ASCO 2021: aanbevolen abstracten specifiek gerelateerd aan borstkanker

Zie ook literatuurlijst niet-toxische middelen en behandelingen specifiek bij borstkanker van arts-bioloog drs. Engelbert Valstar

13 juni 2021: Bron: ASCO 2021:

Hier een aantal aanbevolen abstracten over borstkanker door artsen die zelf voor ASCO werken. Klik op de nummers voor de abstracten. Het zijn veel abstracten want door maar liefst vier verschillende oncologen / artsen zijn lijsten gemaakt.

Aanbevolen door Reshma Mahtani, MD.

Poster Discussion Session: Breast Cancer—Local/Regional/Adjuvant
vailable Starting on Friday, June 4, 2021; 9:00 EDT

507 Usefulness of assessment of circulating tumor DNA(ctDNA) of cerebrospinal fluid(CSF) samples for early detection of brain metastasis (BrM) in patients with triple-negative breast cancer (TNBC). L Raimondi, G Naso, R Lazzeroni, et al

Take-Home Message

This study evaluated whether CSF-derived circulating tumor DNA (ctDNA) predicted brain metastases in 323 women with newly diagnosed triple-negative breast cancer (TNBC). Following treatment with neoadjuvant therapy and surgery, 126 patients (39%) had detectable ctDNA. Brain metastases developed in 98.4% of patients who had detectable ctDNA compared with 1% of patients without detectable ctDNA (P <.001). Compared with patients with detectable ctDNA, those with undetectable cdDNA had significantly better PFS (HR, 0.3) and OS (HR, 0.2). In multivariable analysis, detectable ctDNA was the strongest predictor of the combined outcome of brain metastases and death at 24 months of follow-up (HR, 3.62).

CSF-derived ctDNA following neoadjuvant therapy and surgery is a reliable biomarker of brain metastases and mortality among women diagnosed with TNBC.

517 Abemaciclib combined with adjuvant endocrine therapy in patients with high risk early breast cancer who received neoadjuvant chemotherapy (NAC). M Martin, R Hegg, S-B Kim, et al

Take-Home Message

The phase III monarchE study compared abemaciclib combined with adjuvant endocrine therapy (ET) with ET alone in patients with HR+/HER2– high-risk early breast cancer. The current analysis included 2056 patients with invasive disease previously treated with neoadjuvant chemotherapy. In multivariable analysis, compared with patients who had ET alone, patients who received abemaciclib + ET had significantly better invasive disease–free survival (HR, 0.61; 2-year survival, 87.2% vs 80.6%), and better distant relapse–free survival (HR, 0.61; 2-year survival, 89.5% vs 82.8%). Safety outcomes were similar in both patient groups.

Abemaciclib + ET demonstrated a significant survival benefit in women with invasive, HR+/HER2– high-risk early breast cancer previously treated with neoadjuvant chemotherapy.

Poster Session: Breast Cancer—Local/Regional/Adjuvant
Available Starting on Friday, June 4, 2021; 9:00 EDT

526 Trastuzumab deruxtecan (T-DXd) in patients with HER2+ metastatic breast cancer with brain metastases: A subgroup analysis of the DESTINY-Breast01 trial. GHM Jerusalem, YH Park, T Yamashita, et al

Take-Home Message

Findings of the DESTINY-Breast01 study demonstrated the significant survival benefit associated with the antibody–conjugate drug Trastuzumab deruxtecan (T-DXd) for unresectable or metastatic HER2+ breast cancer previously treated with trastuzumab emtansine. This subanalysis of DESTINY-Breast01 compared patients with and without a history of brain metastases, finding comparable objective response rates (ORR), median progression-free survival (mPFS), and median duration of response (mDoR) in both patient groups. Following treatment with T-DXd, patients with history of brain metastases had an ORR of 58%, an mPFS of 18.1 months, and an mDoR of 16.9 months.

T-DXd showed a strong clinical benefit in patients with unresectable or metastatic HER2+ breast cancer, regardless of brain metastases.

574 Pyrotinib as neoadjuvant therapy for HER2+ breast cancer: A multicenter, randomized, controlled, phase II trial. X Ding, W Mo, X Xie, et al

Take-Home Message

In this phase II trial, patients with cT2-3N0-3M0 stage, HER2+ breast cancer were randomly assigned to receive six cycles of trastuzumab + docetaxel + carboplatin (TCbH; n = 33) or TCbH + pyrotinib (n = 34). Compared with patients in the TCbH arm, those in the TCbH + pyrotinib arm had a significantly better pathological complete response rate (36.7% vs 71.4%) and a numerically better objective response rate (83.3% vs 100%). Diarrhea of grade 3 was the most common adverse event, occurring in 28.6% and 10% of patients in the TCbH + pyrotinib arm and TCbH arm, respectively.

In the setting of neoadjuvant therapy for HER2+ breast cancer, the addition of pyrotinib to TCbH improved treatment responses and had a manageable safety profile.

Poster Session: Breast Cancer—Metastatic
Available Starting on Friday, June 4, 2021; 9:00 EDT

1039 Safety of trastuzumab emtansine (T-DM1) in patients (pts) with HER2-positive locally advanced or metastatic breast cancer (mBC): Final results from KAMILLA Cohorts 1 (global) and 2 (Asia). R Wuerstlein, P Ellis, F Montemurro, et al

Take-Home Message

These authors compared safety outcomes in two patient cohorts from KAMILLA, a trial assessing the safety of the targeted therapy T-DM1 in patients with previously treated, locally advanced or metastatic HER2+ breast cancer. Length of exposure to T-DM1 was similar in the Asian cohort (n = 362) and the global cohort (n = 2002; median, 5.6 vs 5.0 months). Prespecified adverse events (hepatic events, allergic reactions, thrombocytopenia ) of grade ≥3 were more common in the Asian compared with the global cohort, particularly TCP. Treatment-related adverse events were also significantly more common in the Asian (48.6%) compared with the global cohort (18.4%). The cohorts had similar rates of progression-free survival and overall survival.

T-DM1 was associated with higher rates of adverse events of grade ≥3 among Asian compared with global patients, a finding in agreement with that of previous studies. Nevertheless, a survival benefit with T-DM1 for previously treated metastatic breast cancer was seen in all patients.

1043 Updated results of tucatinib versus placebo added to trastuzumab and capecitabine for patients with pretreated HER2+ metastatic breast cancer with and without brain metastases (HER2CLIMB). G Curigliano, V Mueller, VF Borges, et al

Take-Home Message

The report of an updated analysis of HER2CLIMB trial data will present overall survival, progression-free survival, and safety outcomes in the overall study population and stratified by brain metastases, ECOG performance status, and geographic region.

1055 Overall survival in patients with breast cancer treated with a CDK 4/6 inhibitor plus fulvestrant: A U.S. Food and Drug Administration pooled analysis. JJ Gao, J Cheng, TM Prowell, et al

Take-Home Message

The study authors conducted a pooled, exploratory analysis of data from trials evaluating treatment with CDK inhibitors plus fulvestrant for locally advanced or metastatic, HR+/HER2– breast cancer. The addition of a CDK inhibitor to fulvestrant improved overall survival in most patient subgroups, which were defined by demographic and clinicopathologic factors. However, among younger patients (<40 years old; n = 89), the overall survival was better among treated with fulvestrant alone compared with those treated with fulvestrant plus a CDK inhibitor.

In most patient subgroups, the addition of a CDK inhibitor to fulvestrant enhanced survival compared with fulvestrant alone.

1080 Assessment of sacituzumab govitecan (SG) versus treatment of physician’s choice (TPC) cohort by agent in the phase 3 ASCENT study of patients (pts) with metastatic triple-negative breast cancer (mTNBC). LA Carey, D Loirat, K Punie, et al

Take-Home Message

The ASCENT trial evaluated the antibody–drug conjugate sacituzumab govitecan in the setting of metastatic triple-negative breast cancer (mTNBC). This subanalysis evaluated outcomes among patients who had disease recurrence within 12 months of neoadjuvant chemotherapy and one second-line therapy; no patients had brain metastases. Compared with patients who received a second-line treatment of physician’s choice (n = 32), those who received second-line sacituzumab govitecan (n = 33) had significantly longer progression-free survival (median, 5.7 vs 1.5 months) and overall survival (median, 10.9 vs 4.9 months) and objective response rate (30% vs 3%).

Sacituzumab govitecan conferred a significant survival advantage over physician’s choice in the context of second-line treatment in patients with mTNBC but without brain metastases.

Oral Abstract Session: Breast Cancer—Metastatic
Saturday, June 5, 2021; 1:30 PM–4:30 PM EDT

1000 Overall survival (OS) with palbociclib (PAL) + fulvestrant (FUL) in women with hormone receptor–positive (HR+), human epidermal growth factor receptor 2–negative (HER2–) advanced breast cancer (ABC): Updated analyses from PALOMA-3. M Cristofanilli, HS Rugo, S-A Im, et al

Take-Home Message

The phase III PALOMA-3 trial evaluated the addition of palbociclib to fulvestrant (PAL + FUL) for treatment of HR+/HER2– advanced breast cancer with progression following endocrine therapy, finding a significant survival benefit for PAL + FUL compared with FUL alone. The current analysis demonstrates a continuation of this trend. After a median follow-up of 73.3 months, PAL + FUL was associated with better OS compared with FUL alone (HR, 0.81), as well as better 5-year OS rates (23.3% vs 16.8%). This trend was observed in most patient subgroups, except those in which patients were endocrine-resistant or had previous chemotherapy for advanced breast cancer.

Study findings support the continued clinical benefit of PAL + FUL over the longer term for treatment of HR+/HER2– advanced breast cancer.

1001 Updated overall survival (OS) results from the phase III MONALEESA-3 trial of postmenopausal patients (pts) with HR+/HER2- advanced breast cancer (ABC) treated with fulvestrant (FUL) ± ribociclib (RIB). DJ Slamon, P Neven, SKL Chi

Take-Home Message

Findings from the MONALEESA-3 trial demonstrated a survival benefit with ribociclib plus fulvestrant (RIB + FUL) compared with FUL alone for treatment of HR+/HER2– advanced breast cancer in postmenopausal women. This trend continued over longer-term follow-up (median, 56.3 months). Compared with patients who received FUL alone, those who received RIB + FUL had longer overall survival (median, 53.7 vs 41.5 months); this finding was observed regardless of whether patients were receiving first- or second-line therapy. The clinical benefit of RIB + FUL was also observed for progression-free survival and chemotherapy-free survival.

An ongoing clinical benefit of adding to RIB to FUL for treatment of HR+/HER2– advanced breast cancer continued after almost 5 years of follow-up.

1002 Dalpiciclib versus placebo plus fulvestrant in HR+/HER2- advanced breast cancer that relapsed or progressed on previous endocrine therapy (DAWNA-1): A multicenter, randomized, phase 3 study. B Xu, Q Zhang, P Zhang, et al

Take-Home Message

In the phase III DAWNA-1 study, 361 patients with HR+/HER2− locally advanced or metastatic breast cancer were randomized 2:1 to receive fulvestrant plus either dalpiciclib, a novel CDK4/6 inhibitor, or placebo. Progression-free survival was significantly improved in the group receiving dalpiciclib (median 15.7 months vs 7.2 months; HR, 0.42; 95% CI, 0.31–0.58; P < .0001).

Adding dalpiciclib to fulvestrant improved progression-free survival in patients with HR+/HER2− advanced/metastatic breast cancer.

Oral Abstract Session: Breast Cancer—Local/Regional/Adjuvant
Sunday, June 6, 2021; 8:00 AM–11:00 AM EDT

500 Outcome of patients with an ultralow risk 70-gene signature in the MINDACT trial. JL Cardozo, C Drukker, M Schmidt, et al

Take-Home Message

Study authors used data from the phase III MINDACT trial to assess survival among 1000 patients stratified on the 70-gene MammaPrint assay (MP) as ultra–low risk for distant recurrence of breast cancer. The overall 8-year distant metastasis–free interval (DMFI) in ultra–low risk patients was 97%; DMFI was similar after adjustment for tumor and treatment characteristics.

Patients stratified as ultra–low risk for distant recurrence of breast cancer on MP had an 8-year survival rate of over 95%, regardless of treatment or tumor type.

501 Breast Cancer Index (BCI) and prediction of benefit from extended aromatase inhibitor (AI) therapy (tx) in HR+ breast cancer: NRG oncology/NSABP B-42. EP Mamounas, H Bandos, P Rastogi, et al

Take-Home Message

In the phase III NSABP B-42 trial, the authors evaluated extended letrozole treatment (ELT) among 2179 patients with HR+ breast cancer who had completed 5 years of endocrine therapy. Overall, ELT improved 10-year recurrence-free survival by 1.6%. Breast cancer–free survival, disease-free survival, and distant recurrence over the shorter-term (<4 years) did not vary significantly by the Breast Cancer Index (BCI) HOXB13/IL17BR ratio (BCI-H/I). However, after 4 years of follow-up, ELT significantly reduced distant recurrence among patients with a high BCI-H/I (HR, 0.29; P = .003) but not among patients with a low BCI-H/I (HR, 0.68; P = .28).

The BCI-H/I did not predict the effect of ELT on 10-year recurrence-free survival among patients with HR+ breast cancer. Beyond 4 years of follow-up, ELT reduced distant recurrence but only among patients with a high BCI-H/I.

502 Utility of the 70-gene MammaPrint assay for prediction of benefit from extended letrozole therapy (ELT) in the NRG Oncology/NSABP B-42 trial. P Rastogi, H Bandos, PC Lucas, et al

Take-Home Message

In the phase III NSABP B-42 trial, the study investigators evaluated whether the 70-gene MammaPrint assay (MP) predicted the benefit of extended letrozole treatment (ELT) among patients with HR+ breast cancer who had completed 5 years of endocrine therapy. ELT had a significant benefit in terms of distant recurrence among patients stratified by MP as low risk (HR, 0.43; P = .002) but not among patients stratified as high-risk (HR, 0.65; P = .19). Similar trends were observed for disease-free survival and breast cancer–free survival. Among patients stratified by MP as low risk, those with ultra-low risk had the greatest benefit from ELT for all outcomes.

In the setting of HR+ breast cancer, a significant benefit of ELT was observed among patients stratified as low risk on MP but not among those stratified as high risk. The benefit was greatest among patients with ultra-low risk.

503 De-escalated neoadjuvant pertuzumab+trastuzumab with or without paclitaxel weekly in HR-/HER2+ early breast cancer: ADAPT-HR-/HER2+ biomarker and survival results. N Harbeck, O Gluz, M Christgen, et al

Take-Home Message

The authors present first survival data for the ADAPT HR−/HER2+ study, in which 134 patients with HR-negative (ER and PR <1%) and HER2-positive tumors were randomly assigned to receive four cycles of neoadjuvant pertuzumab (P) plus trastuzumab (T) with or without paclitaxel (PAC), with the aim of comparing partial complete response in the two arms.

Because of the partial complete response superiority observed for the P+T+PAC group, the trial was stopped early. Of the 69 patients with a partial complete response, 39 (56.5%) did not receive further chemotherapy (9 in the P+T group vs 30 in the P+T+PAC group). A single distant relapse (1.4%) occurred.

505 Neoadjuvant talazoparib in patients with germline BRCA1/2 (gBRCA1/2) mutation-positive, early HER2-negative breast cancer (BC): Results of a phase 2 study. JK Litton, JT Beck, JM Jones, et al

Take-Home Message

This phase II nonrandomized single-arm study evaluated the safety and efficacy of PARP inhibitor talazoparib in patients with germline BRCA1/2–mutated HER2-negative locally advanced or metastatic breast cancer. The primary endpoint was pathologic complete response after 24 weeks of neoadjuvant talazoparib (1 mg daily) monotherapy followed by surgery. All 61 patients had triple-negative disease; 48 patients comprised the evaluable population. Approximately 98% of the patients experienced treatment-emergent adverse events, primarily fatigue, nausea, and alopecia.

Results showed talazoparib to be well-tolerated overall and active in the neoadjuvant setting, with pathologic complete response rates similar to rates noted with combined anthracycline and taxane regimens.

506 Durvalumab improves long-term outcome in TNBC: results from the phase II randomized GeparNUEVO study investigating neodjuvant durvalumab in addition to an anthracycline/taxane based neoadjuvant chemotherapy in early triple-negative breast cancer (TNBC). S Loibl, A Schneeweiss, JB Huober, et al

Take-Home Message

The GeparNeuvo study was designed to examine the benefits of adding durvalumab to preoperative chemotherapy in early-stage A total of 174 patients with cT1b-cT4a-d tumors and centrally confirmed TNBC were randomized to receive either durvalumab or placebo monotherapy for 2 weeks, followed by the addition of nab-paclitaxel weekly for 12 weeks and then durvalumab/placebo plus epirubicin/cyclophosphamide every 2 weeks for four cycles.

The 3-year invasive disease–free survival with durvalumab was 84.9% versus 76.9% with placebo, and 3-year overall survival with durvalumab was 95.1% versus 83.1% with placebo. Durvalumab appears to improve long-term outcomes in patients with TNBC.

605 A randomized phase III post-operative trial of platinum-based chemotherapy (P) versus capecitabine (C) in patients (pts) with residual triple-negative breast cancer (TNBC) following neoadjuvant chemotherapy (NAC): ECOG-ACRIN EA1131. IA Mayer, F Zhao, CL Arteaga, et al

Take-Home Message

The authors sought to determine whether the use of platinum chemotherapy is superior to use of capecitabine for improving invasive disease–free survival (IDFS) in patients with basal-subtype early-stage TNBC and residual disease after preoperative chemotherapy. A total of 401 patients with clinical stage II/III TNBC (310 with basal subtype) and ≥1 cm residual invasive disease post neoadjuvant chemotherapy were randomized 1:1 to receive either platinum-based chemotherapy (carboplatin or cisplatin) or capecitabine.

The 3-year IDFS was 40% for the platinum group and 44% for the capecitabine group. The trial was stopped upon recommendation at the fifth interim analysis because of the unlikelihood that it would demonstrate noninferiority or superiority of the platinum regimen. In patients with TNBC, in particular those with the basal subtype, and ≥1 cm residual disease after neoadjuvant chemotherapy, adjuvant platinum chemotherapy did not improve outcomes.

Plenary Session
Sunday, June 6, 2021; 1:00 PM–4:00 PM EDT

LBA1 OlympiA: A phase III, multicenter, randomized, placebo-controlled trial of adjuvant olaparib after (neo)adjuvant chemotherapy in patients with germline BRCA1/2 mutations and high-risk HER2-negative early breast cancer. A Tutt, JE Garber, B Kaufman, et al

Take-Home Message

This plenary session presentation demonstrates the benefits of adjuvant olaparib in early-stage BRCA-mutant breast cancer.

Aanbevolen door Lee Schwartzberg, MD en FCAP

Oral Abstract Session: Breast Cancer—Metastatic
Saturday, June 5, 2021; 1:30 PM–4:30 PM EDT

Take-Home Message

The phase III PALOMA-3 trial evaluated the addition of palbociclib to fulvestrant (PAL + FUL) for treatment of HR+/HER2– advanced breast cancer with progression following endocrine therapy, finding a significant survival benefit for PAL + FUL compared with FUL alone. The current analysis demonstrates a continuation of this trend. After a median follow-up of 73.3 months, PAL + FUL was associated with better OS compared with FUL alone (HR, 0.81), as well as better 5-year OS rates (23.3% vs 16.8%). This trend was observed in most patient subgroups, except those in which patients were endocrine-resistant or had previous chemotherapy for advanced breast cancer.

Study findings support the continued clinical benefit of PAL + FUL over the longer term for treatment of HR+/HER2– advanced breast cancer.

Take-Home Message

Findings from the MONALEESA-3 trial demonstrated a survival benefit with ribociclib plus fulvestrant (RIB + FUL) compared with FUL alone for treatment of HR+/HER2– advanced breast cancer in postmenopausal women. This trend continued over longer-term follow-up (median, 56.3 months). Compared with patients who received FUL alone, those who received RIB + FUL had longer overall survival (median, 53.7 vs 41.5 months); this finding was observed regardless of whether patients were receiving first- or second-line therapy. The clinical benefit of RIB + FUL was also observed for progression-free survival and chemotherapy-free survival.

An ongoing clinical benefit of adding to RIB to FUL for treatment of HR+/HER2– advanced breast cancer continued after almost 5 years of follow-up.

Take-Home Message

In the phase III DAWNA-1 study, 361 patients with HR+/HER2− locally advanced or metastatic breast cancer were randomized 2:1 to receive fulvestrant plus either dalpiciclib, a novel CDK4/6 inhibitor, or placebo. Progression-free survival was significantly improved in the group receiving dalpiciclib (median 15.7 months vs 7.2 months; HR, 0.42; 95% CI, 0.31–0.58; P < .0001).

Adding dalpiciclib to fulvestrant improved progression-free survival in patients with HR+/HER2− advanced/metastatic breast cancer.

1003 Trastuzumab plus endocrine therapy or chemotherapy as first-line treatment for metastatic breast cancer with hormone receptor-positive and HER2-positive: The sysucc-002 randomized clinical trial. Z Yuan, J-J Huang, X Hua, et al

Take-Home Message

The open-label, randomized, controlled phase III SYSUCC-002 trial was designed to compare the efficacy of trastuzumab plus endocrine therapy (ET group) with that of trastuzumab plus chemotherapy (CT group). A total of 392 patients with HR+ and HER2+ histologically confirmed advanced breast cancer were randomized 1:1 to the two groups. Median progression-free survival was 19.2 months in the ET group versus 14.8 months in the CT group (HR, 0.88; 95% CI, 0.71–1.09; noninferiority P < .0001), with the patients in the CT group experiencing significantly more toxicities.

Trastuzumab plus endocrine therapy was noninferior to trastuzumab plus chemotherapy and resulted in fewer toxic effects.

Oral Abstract Session: Breast Cancer—Local/Regional/Adjuvant
Sunday, June 6, 2021; 8:00 AM–11:00 AM EDT

500 Outcome of patients with an ultralow risk 70-gene signature in the MINDACT trial. JL Cardozo, C Drukker, M Schmidt, et al

Take-Home Message

Study authors used data from the phase III MINDACT trial to assess survival among 1000 patients stratified on the 70-gene MammaPrint assay (MP) as ultra–low risk for distant recurrence of breast cancer. The overall 8-year distant metastasis–free interval (DMFI) in ultra–low risk patients was 97%; DMFI was similar after adjustment for tumor and treatment characteristics.
Patients stratified as ultra–low risk for distant recurrence of breast cancer on MP had an 8-year survival rate of over 95%, regardless of treatment or tumor type.

Take-Home Message

The authors present first survival data for the ADAPT HR−/HER2+ study, in which 134 patients with HR-negative (ER and PR <1%) and HER2-positive tumors were randomly assigned to receive four cycles of neoadjuvant pertuzumab (P) plus trastuzumab (T) with or without paclitaxel (PAC), with the aim of comparing partial complete response in the two arms.
Because of the partial complete response superiority observed for the P+T+PAC group, the trial was stopped early. Of the 69 patients with a partial complete response, 39 (56.5%) did not receive further chemotherapy (9 in the P+T group vs 30 in the P+T+PAC group). A single distant relapse (1.4%) occurred.

Take-Home Message

This phase II nonrandomized single-arm study evaluated the safety and efficacy of PARP inhibitor talazoparib in patients with germline BRCA1/2–mutated HER2-negative locally advanced or metastatic breast cancer. The primary endpoint was pathologic complete response after 24 weeks of neoadjuvant talazoparib (1 mg daily) monotherapy followed by surgery. All 61 patients had triple-negative disease; 48 patients comprised the evaluable population. Approximately 98% of the patients experienced treatment-emergent adverse events, primarily fatigue, nausea, and alopecia.

Results showed talazoparib to be well-tolerated overall and active in the neoadjuvant setting, with pathologic complete response rates similar to rates noted with combined anthracycline and taxane regimens.

Take-Home Message

The authors sought to determine whether the use of platinum chemotherapy is superior to use of capecitabine for improving invasive disease–free survival (IDFS) in patients with basal-subtype early-stage TNBC and residual disease after preoperative chemotherapy. A total of 401 patients with clinical stage II/III TNBC (310 with basal subtype) and ≥1 cm residual invasive disease post neoadjuvant chemotherapy were randomized 1:1 to receive either platinum-based chemotherapy (carboplatin or cisplatin) or capecitabine.

The 3-year IDFS was 40% for the platinum group and 44% for the capecitabine group. The trial was stopped upon recommendation at the fifth interim analysis because of the unlikelihood that it would demonstrate noninferiority or superiority of the platinum regimen. In patients with TNBC, in particular those with the basal subtype, and ≥1 cm residual disease after neoadjuvant chemotherapy, adjuvant platinum chemotherapy did not improve outcomes.

Plenary Session
Sunday, June 6, 2021; 1:00 PM–4:00 PM EDT

Take-Home Message

This plenary session presentation demonstrates the benefits of adjuvant olaparib in early-stage BRCA-mutant breast cancer.

Aanbevolen door Sara M. Tolaney MD, MPH

Poster Discussion Session: Breast Cancer—Metastatic
Available Starting on Friday, June 4, 2021; 9:00 EDT

1022 RC48-ADC, a HER2-targeting antibody-drug conjugate, in patients with HER2-positive and HER2-low expressing advanced or metastatic breast cancer: A pooled analysis of two studies. J Wang, Y Liu, Q Zhang, et al

Take-Home Message

The authors pooled analysis of the C001 CANCER and C003 CANCER studies to assess the safety and efficacy of RC48, a novel HER2-targeting antibody–drug conjugate. A total of 118 patients with breast cancer received RC48-ADC; 70 were HER2-positive, and 48 were HER2–low-expressing. In the HER2-positive patients, ORRs were 22.2%, 42.9%, and 40.0% for doses of 1.5, 2.0, and 2.5 mg/kg, respectively. In the HER2–low-expressing patients (dose, 2.0 mg/kg), the ORR was 39.6%. Most treatment-related adverse events were grade 1 or 2.

RC48 is a novel HER2-targeting antibody–drug conjugate that was shown to be effective and well-tolerated in HER2-positive and HER2–low-expressing subgroups.

1023 BEGONIA: Phase 1b/2 study of durvalumab (D) combinations in locally advanced/metastatic triple-negative breast cancer (TNBC)—Initial results from arm 1, d+paclitaxel (P), and arm 6, d+trastuzumab deruxtecan (T-DXd). P Schmid, S-A Im, A Armstrong, et al

Take-Home Message

The authors present preliminary data from the BEGONIA trial for the combinations of durvalumab (D) plus trastuzumab deruxtecan (T-DXd) or paclitaxel (P) as first-line therapy in patients with metastatic triple-negative breast cancer. Patients in arm 1 of BEGONIA received D+P (n = 23); confirmed ORR was 57% (13/23), with 54% of those patients retaining response after 12 months. Patients in arm 6 received D+ T-DXd (n = 11); confirmed ORR was 100% (4/4 patients with completed on-treatment disease assessments), with 100% retaining response at data cutoff.

The combination D+P was well-tolerated, and the response rate was as expected for such a combination. Patient enrollment for D+T-DXd is ongoing, with the combination demonstrating promise.

Poster Session: Breast Cancer—Metastatic
Available Starting on Friday, June 4, 2021; 9:00 EDT

1038 Safety and unique pharmacokinetic profile of ARX788, a site-specific ADC, in heavily pretreated patients with HER2-overexpresing solid tumors: Results from two phase 1 clinical trials. SA Hurvitz, H Park, S Frentzas, et al

Take-Home Message

The authors present phase I data on the pharmacokinetics, safety, and activity of ARX788, a novel anti-HER2 antibody–drug conjugate, against advanced solid tumors. A total of 103 pretreated patients in the ACE-Breast-01 and ACE-Pan Tumor-01 trials received ARX788 monotherapy; ORRs for those receiving the 1.5-mg/kg dose were 74% (14/19) and 67% (2/3) in the two trials, respectively.

ARX788 was well-tolerated, with most adverse events being grade 1–2. Low systemic toxicity was noted, and pharmacokinetic profiles were comparable for all dose levels.

Plenary Session
Sunday, June 6, 2021; 1:00 PM–4:00 PM EDT

Take-Home Message

This plenary session presentation demonstrates the benefits of adjuvant olaparib in early-stage BRCA-mutant breast cancer.

Oral Abstract Session: Breast Cancer—Metastatic
Saturday, June 5, 2021; 1:30 PM–4:30 PM EDT

Take-Home Message

In the phase III DAWNA-1 study, 361 patients with HR+/HER2− locally advanced or metastatic breast cancer were randomized 2:1 to receive fulvestrant plus either dalpiciclib, a novel CDK4/6 inhibitor, or placebo. Progression-free survival was significantly improved in the group receiving dalpiciclib (median 15.7 months vs 7.2 months; HR, 0.42; 95% CI, 0.31–0.58; P < .0001).

Adding dalpiciclib to fulvestrant improved progression-free survival in patients with HR+/HER2− advanced/metastatic breast cancer.

Take-Home Message

The open-label, randomized, controlled phase III SYSUCC-002 trial was designed to compare the efficacy of trastuzumab plus endocrine therapy (ET group) with that of trastuzumab plus chemotherapy (CT group). A total of 392 patients with HR+ and HER2+ histologically confirmed advanced breast cancer were randomized 1:1 to the two groups. Median progression-free survival was 19.2 months in the ET group versus 14.8 months in the CT group (HR, 0.88; 95% CI, 0.71–1.09; noninferiority P < .0001), with the patients in the CT group experiencing significantly more toxicities.

Trastuzumab plus endocrine therapy was noninferior to trastuzumab plus chemotherapy and resulted in fewer toxic effects.

1006 The tumor microenvironment (TME) and atezolizumab + nab-paclitaxel (A+nP) activity in metastatic triple-negative breast cancer (mTNBC): IMpassion130. LA Emens, LD Goldstein, P Schmid, et al

Take-Home Message

The authors of the IMpassion130 study investigated the tumor microenvironment (TME) and its association with outcomes in patients with metastatic triple-negative breast cancer. The present analysis concerns the TME as it relates to the efficacy of atezolizumab plus nab-paclitaxel therapy.

Sensitivity to cancer immunotherapy was greatest for PD-L1 immune cell–positive inflamed tumors and PD-L1 immune cell–positive basal-like immune activated tumors. Patients with luminal androgen receptor tumors may be resistant to cancer immunotherapy.

Oral Abstract Session: Breast Cancer—Local/Regional/Adjuvant
Sunday, June 6, 2021; 8:00 AM–11:00 AM EDT

Take-Home Message

The authors present first survival data for the ADAPT HR−/HER2+ study, in which 134 patients with HR-negative (ER and PR <1%) and HER2-positive tumors were randomly assigned to receive four cycles of neoadjuvant pertuzumab (P) plus trastuzumab (T) with or without paclitaxel (PAC), with the aim of comparing partial complete response in the two arms.

Because of the partial complete response superiority observed for the P+T+PAC group, the trial was stopped early. Of the 69 patients with a partial complete response, 39 (56.5%) did not receive further chemotherapy (9 in the P+T group vs 30 in the P+T+PAC group). A single distant relapse (1.4%) occurred.

Take-Home Message

The GeparNeuvo study was designed to examine the benefits of adding durvalumab to preoperative chemotherapy in early-stage A total of 174 patients with cT1b-cT4a-d tumors and centrally confirmed TNBC were randomized to receive either durvalumab or placebo monotherapy for 2 weeks, followed by the addition of nab-paclitaxel weekly for 12 weeks and then durvalumab/placebo plus epirubicin/cyclophosphamide every 2 weeks for four cycles.

The 3-year invasive disease–free survival with durvalumab was 84.9% versus 76.9% with placebo, and 3-year overall survival with durvalumab was 95.1% versus 83.1% with placebo. Durvalumab appears to improve long-term outcomes in patients with TNBC.

Take-Home Message

The authors sought to determine whether the use of platinum chemotherapy is superior to use of capecitabine for improving invasive disease–free survival (IDFS) in patients with basal-subtype early-stage TNBC and residual disease after preoperative chemotherapy. A total of 401 patients with clinical stage II/III TNBC (310 with basal subtype) and ≥1 cm residual invasive disease post neoadjuvant chemotherapy were randomized 1:1 to receive either platinum-based chemotherapy (carboplatin or cisplatin) or capecitabine.

The 3-year IDFS was 40% for the platinum group and 44% for the capecitabine group. The trial was stopped upon recommendation at the fifth interim analysis because of the unlikelihood that it would demonstrate noninferiority or superiority of the platinum regimen. In patients with TNBC, in particular those with the basal subtype, and ≥1 cm residual disease after neoadjuvant chemotherapy, adjuvant platinum chemotherapy did not improve outcomes.

Aanbevolen door Lillie D. Shockney RN, BS, MAS, ONN-CG

Poster Session: Breast Cancer—Metastatic
Available Starting on Friday, June 4, 2021; 9:00 EDT

1048 Real-world cost-effectiveness of pertuzumab (P) with trastuzumab + chemo (T+Chemo) in patients (pts) with metastatic breast cancer (MBC): A population-based retrospective cohort study by the Canadian Real-world Evidence for Value in Cancer Drugs (CanREValue) collaboration. WF Dai, JM Beca, C Nagamuthu, et al

Take-Home Message

This retrospective cohort analysis evaluated the real-world population-based effectiveness and cost-effectiveness of pertuzumab (P) treatment in 1823 metastatic breast cancer (MBC) patients between January 2008 and March 2018 in Ontario, Canada. Controls were treated prior to universal public funding of P in November 2013 and received only trastuzumab (T). After November 2013, study patients received P and T treatments. These study patients demonstrated increased overall survival (OS; HR = 0.66), with a median of 3.4 years compared with the control group’s median OS of 2.1 years. The addition of P also increased life years gained (LYG) by 0.63. The data demonstrated the probability of the addition of P to be cost-effective as <1%, mainly due to drug and cancer clinic costs.

The addition of P to T in the treatment of MBC does increase OS, but it does so at significant cost.

1071 Real-world quality of life (QoL) in black, indigenous and people of color (BIPOC) treated with palbociclib (PAL) and endocrine therapy for hormone receptor–positive (HR+)/human epidermal growth factor receptor 2–negative (HER2–) advanced breast cancer (ABC): A subgroup analysis from POLARIS. GB Rocque, JL Blum, A Montero, et al

Take-Home Message

This subgroup analysis from the POLARIS study included 233 black, indigenous, and people of color (BIPOC) being treated for breast cancer with palbociclib (PAL) to evaluate whether racial disparity affects quality of life (QoL). Scores evaluating specific side-effect symptoms, including nausea and vomiting, pain, dyspnea, insomnia, appetite loss, constipation, and diarrhea, remained stable over the first year of PAL treatment. Mean EORTC QLQ-C30 global health QoL and functional scales scores also remained stable during that timeframe.

There was no significant adverse effect of PAL treatment on QOL in BIPOC.

1095 Survival among patients with untreated metastatic breast cancer. JK Plichta, SM Thomas, S Sammons, et al

Take-Home Message

This study evaluated the survival outcomes of metastatic breast cancer (MBC) patients who opted to receive no treatment for their disease. The medial unadjusted overall survival (OS) in the untreated group was 2.5 months versus 36.4 months in the treated group (P < .001). Higher tumor grade, higher comorbidity score, increased age, and triple negative (vs HR+/HER2−) tumor subtype (all P < .05) were all associated with decreased OS in the untreated cohort; however, the number of metastatic sites was shown not to be associated with OS.

Patients with MBC who choose to forgo treatment are more likely to have comorbid conditions, be of advanced age, and have clinically aggressive disease. The prognosis for untreated MBC is extremely poor.

Poster Discussion Session: Breast Cancer—Metastatic
Available Starting on Friday, June 4, 2021; 9:00 EDT

1015 Characterizing demographics, clinical, and genomic characteristics for U.S. patients with HR+, HER2- metastatic breast cancer following progression on a CDK4 and 6 inhibitor. F Andre, A Aggarwal, X Rao, et al

Take-Home Message

This retrospective study was designed to aid in the development of treatment strategies for metastatic breast cancer (MBC) patients with hormone receptor–positive (HR+), human epidermal growth factor receptor 2–negative (HER2−) disease following progression on CDK4/6 inhibitors with or without endocrine therapy. Two cohorts of US patients were identified: all 369 patients had been diagnosed with HR+, HER2− MBC in January 2011 or later. Biopsy was obtained from the first cohort following progression on a CDK4/6 inhibitor with or without endocrine therapy (Cohortpost). Biopsy was obtained from the second group, which had no evidence of CDK4/6 inhibitor treatment (Cohortpre). The results demonstrated that patients in Cohortpost had a significantly higher tumor mutation burden compared with patients in Cohortpre (median, 2.92 vs 1.67; P < .0001).

Additional study is needed to increase understanding of the mutational and transcriptional signatures and timing of resistance leading to progression associated with CDK4/6 inhibitors with or without endocrine therapy. That knowledge will then lead to the development of treatment options for MBC patients who are post progression.

Poster Session: Breast Cancer—Local/Regional/Adjuvant
Available Starting on Friday, June 4, 2021; 9:00 EDT

528 The impact of COVID-19 on breast cancer stage at diagnosis. MR Lloyd, SJ Stephens, JC Hong, et al

Take-Home Message

Routine screening mammography was stopped during the beginning months of the SARS-CoV-2 pandemic in spring 2020. The number of new breast cancer diagnoses per month decreased significantly during the shutdown. The number of patients diagnosed later in the year with stage III or IV disease was markedly increased as compared with the previous 4 years (6.6% in the control cohort compared with 12.6% in the 2020 test cohort; P < .001). Later stage at time of diagnosis was associated with year of diagnosis (2020 vs 2016–2019; OR, 4.25; P < .001), low income (<200% of the federal poverty level; OR, 2.73; P = .006) and increased Charlson Comorbidity Index (OR, 12.01; P < .001.

Late-stage breast cancer diagnoses were increased in the later months of 2020 following the global shutdown due to the SARS-CoV-2 pandemic, especially in patients with comorbidities and lower income.

Poster Session: Health Services Research and Quality Improvement
Available Starting on Friday, June 4, 2021; 9:00 EDT

6525 Impact of Medicaid expansion on two-year mortality among stage IV breast cancer (BC) patients according to race. C Malinowski, X Lei, H Zhao, et al

Take-Home Message

This study of 7675 patients evaluated the impact of Medicaid expansion on the 2-year mortality rate of metastatic breast cancer patients according to race. Patients diagnosed with stage IV metastatic disease were placed in either the pre-expansion period (2010–2013) or the post-expansion period (2014–2015) based on date of diagnosis. The 2-year mortality rate decreased among white patients from the pre-expansion period to the post-expansion period (42.5% to 38.7%) and among non-white patients in the same time periods (45.4% to 36.4%). Death rates of non-whites compared with whites were higher in the pre-expansion period (HR, 1.14; P = .04). In the post-expansion period, no difference in death rate was seen between the groups (HR, 0.93; P = .31).

Medicaid expansion decreased the 2-year mortality rate of patients with metastatic breast cancer and narrowed the gap between death rates of non-whites and whites.

6541 Racial disparities in second-line (2L) treatment and overall survival among patients (pts) with hormone receptor positive HER2 negative (HR+HER2-) metastatic breast cancer (mBC) treated in routine practice. X Wang, M Ascha, T Green, et al

Take-Home Message

This study evaluated the effects of racial differences on outcomes and survival rates associated with second-line treatment in patients with HR-positive, HER2-negative metastatic breast cancer. Black patients exhibited a 48% higher mortality rate if they had received CDK4/6 inhibitors (CDKi) in the second first line but not if they received CDKi in the first line (aHR, 1.48). They had a 49% higher mortality rate if they received endocrine monotherapy (aHR, 1.49) in the second line. White patients demonstrated a median real-world overall survival (rwOS) of 25.6 months as compared with black patients, who exhibited a rwOS of 20.4 months. rwOS was decreased among black patients in all second-line treatment groups.

The findings suggest that black patients with metastatic breast cancer who did not receive CDKi in the first line had poorer rwOS as compared with white patients, even after receiving CDKi in the second line.

Publication-Only Abstract Titles
Breast Cancer—Local/Regional/Adjuvant

e13036 Impact of race on the utilization and efficacy of CDK4/6i: Result from a real world database. SS Dawood, K Brzozowski

Take Home Message

This retrospective analysis evaluated the clinical use and prognostic impact of CDK4/6 inhibitors (CDK4/6i) in white and black patients with HR-positive/HER2-negative metastatic breast cancer. There was no significant difference in overall survival (OS) between white and black patients who received CDK4/6i (HR, 0.94; P = .80). The 2-year OS was 69.9% for white patients and 69.5% for black patients.

OS rates of white and black patients are similar when CDK4/6i are used in treating HR-positive/HER2-negative metastatic disease.

e13065 Relationship between tumor size and metastatic site in patients with stage IV breast cancer: A large SEER-based study. Q Dong, M Zhang, D Jiang

Take Home Message

In this analysis, the relationship between tumor size and metastatic site in stage IV breast cancer patients was studied. A higher incidence of bone metastasis then brain metastasis was demonstrated regardless of tumor size. Liver and lung metastases were also seen in various subtypes of breast cancer.

Site of metastasis in patients with stage IV metastatic breast cancer is significantly different based on the subtype of the cancer. This information is beneficial in evidence-based decision-making for treatment of these patients.

e18566 Cancer disparities among patients with advanced metastatic breast cancer. D Saravia, L Elson, H Liang, et al

Take Home Message

This study evaluated conditions predictive of overall survival in a cohort of 47,032 patients with stage IV metastatic breast cancer. Conditions shown to increase the risk of death in patients with metastatic breast cancer included visceral involvement compared with bone-only involvement, male gender, income <$38,000, insurance coverage through the government, and triple-negative disease. Patients who received chemotherapy and not hormonal therapy were found to have a poorer prognosis. In addition, black patients had higher mortality rates as compared with white patients.

Regardless of subtype, certain sociodemographic conditions affect overall survival rates among patients with stage IV metastatic disease. Improving treatment approaches and focusing on these conditions may improve outcomes for patients in these sociodemographic groups.

Aanbevolen abstracten voor borstkanker en Covid-19 door Benjamin O. Anderson MD, FACS

Poster Session: Breast Cancer—Local/Regional/Adjuvant
Available Starting on Friday, June 4, 2021; 9:00 EDT

528 The impact of COVID-19 on breast cancer stage at diagnosis. MR Lloyd, SJ Stephens, JC Hong, et al

Take-Home Message

The study authors evaluated whether reduced availability in the US of mammography during the COVID-19 pandemic delayed diagnosis of breast cancer. Using data from patients identified in the Beth Israel Deaconess Medical Center Cancer Registry (mean age at diagnosis, 60 years; 69% White), the authors compared monthly screening volumes and stage of breast cancer diagnosis before (2016–2019) and during (2020) the COVID-19 pandemic. In total, 1597 patients were diagnosed before the epidemic and 333, during the pandemic. The volume of mammographies conducted was 90% lower during March to June, 2020, compared with the volume conducted before the pandemic. The proportion of patients diagnosed with late-stage disease was significantly higher during the pandemic (12.6%) compared with before the pandemic (6.6%). On multivariate analysis, factors associated with late-stage diagnosis were initial diagnosis during the pandemic, lower income, and increased Charlson Comorbidity Index.

Reduced access to screening and diagnostic mammography during the COVID-19 pandemic was associated with an increased risk of late-stage breast cancer diagnosis, particularly in patients with low-incomes and/or comorbidities.

543 Survival following locoregional recurrence in breast cancer by clinical subtype. K Allen, CA Lohrisch, D Le, et al

Take-Home Message

Study authors evaluated the impact of clinical subtype and locoregional recurrence (LRR) on breast cancer survival among 492 patients treated during the era of adjuvant therapy (2005–2013). Tumor subtypes evaluated were luminal A, luminal B, and triple negative. Median patient follow-up was 7.2 years from LRR and 11.8 years from diagnosis. LRR was predominantly local (accounting for 69.3%); regional recurrence was associated with higher cancer stage, grade, and luminal status. Over half of patients did not complete adjuvant therapy. Occurrence of local versus regional LRR did not affect completion of adjuvant therapy or median time to death from LRR. However, overall survival after LRR varied by tumor subtype, being lowest among patients with triple-negative disease (median, 3.1 years) and highest among those with luminal A (median not reached; 64.7% of patients had >10-year survival).

Study findings highlight differences in survival time following LRR based on tumor subtype, the biological basis of which, if clarified, could help define patient-tailored therapies.

551 Population-based estimates of the age-specific cumulative risk of breast cancer for pathogenic variants in CHEK2: Findings from the Australian Breast Cancer Family Registry. T Nguyen-Dumont, J Dowty, JA Steen, et al

Take-Home Message

Study authors conducted a genetic screen of CHEK2 in a population-based case-control family study of breast cancer from Australia to evaluate the risk of breast cancer associated with all CHEK2 pathogenic variants. Prior estimates of this risk have been predominantly based on the 1100delC variant of CHEK2. In segregation analysis, carriage of CHEK2 (all variants) was associated with a 4.9-fold increased risk of breast cancer compared with noncarriage. Excess risk of breast cancer was less pronounced in carriers of the 1100delC variant of CHEK2 (HR, 3.5) than in carriers of other CHEK2 variants (HR, 5.7). CHEK2 carriage was associated with appreciable age-specific cumulative risks of breast cancer: risk was 18% to age 60 years and 33% to age 80 years.

Study findings help inform clinical management of breast cancer risk in women who carry CHEK2

575 Racial differences and trends in pathologic complete response following neoadjuvant chemotherapy for breast cancer. SJ Ma, B Yu, LM Serra, et al

Take-Home Message

Using data from the National Cancer Database, the study authors evaluated the effect of racial group on pathologic complete response (pCR) rates among 105,804 patients receiving neoadjuvant chemotherapy for breast cancer. The likelihood of pCR varied by racial group and tumor type.

Findings of this large nationwide study of breast cancer patients treated with adjuvant therapy highlight differences in pCR and overall survival by racial group and tumor type.

Clinical Science Symposium
Available Starting on Friday, June 4, 2021; 9:00 EDT

1009 Disparities within luminal breast cancer: Clinical and molecular features of African American and non-Hispanic white patients. K Hoskins, OC Danciu, VK Gadi, et al

Take-Home Message

To evaluate racial differences in gene expression in breast cancer, study authors conducted 70-gene signature (MammaPrint )/80-gene signature (BluePrint) testing of luminal tumors in African American (n = 364) and non-Hispanic White women (n = 400) recruited in a prospective study of stage I–III breast cancer. Age-matched comparisons between non-Hispanic White women and African American women revealed significant between-group differences in obesity, type 2 diabetes status, and nodal stage, and a greater frequency of MP high-risk tumors in African American women. In an age-matched genetic analysis of luminal B tumors comparing White and African American women, over 1000 differentially expressed genes (DEGs) were identified.

Substantial racial differences in gene expression are present in luminal breast tumors. While the biological basis of this finding is unclear, shared DEGs across breast and basal tumors in African American women suggest that racial factors may drive gene expression in multiple tumor types.

Poster Session: Breast Cancer—Metastatic
Available Starting on Friday, June 4, 2021; 9:00 EDT

1084 Distant metastases after diagnosis: Racial disparities in breast cancer outcomes. J Blanter, I Ramer, J Ray, et al

Take-Home Message

To identify factors associated with distant metastases in breast cancer, the study authors analyzed electronic medical records of women (340 White and 110 Black) previously enrolled in a study of breast cancer prognosis. Distant metastases developed after diagnosis in 11 women (4 White and 7 Black). In analysis adjusted for age, race, and stage at diagnosis, factors significantly associated with distant metastases were younger age and advanced stage at diagnosis.

Distant metastases, an important contributor to breast cancer death, were substantially more likely in Black compared with White women, even after controlling for disease stage. The big question, which may or may not be addressed in this study, is whether this is because treatment is less effective in these women or whether these women are less likely to complete therapy. The underlying causes of the racial disparity in breast cancer metastases require further investigation.

1092 Decreased enrollment of patients with advanced lobular breast cancer compared to ductal breast cancer in interventional clinical trials. MK Abel, ME Melisko, HS Rugo, et al

Take-Home Message

Investigators evaluated the use of RECIST in breast cancer clinical trials. RECIST is intended for measurable tumors, more common in invasive ductal carcinoma of the breast than in invasive lobular carcinoma; thus, its use could influence the representation of histology and stage in clinical trials. In total, 74% of 146 ongoing interventional trials of stage IV breast cancer (registered in gov) used RECIST. The authors compared patients from the UCSF Cancer Registry (n = 8679) with patients from the University of California, San Francisco, clinical trials management system (CTMS; n = 1511). In an analysis of stage IV disease, a significantly lower proportion of patients with invasive lobular carcinoma were included in the CTMS than in the cancer registry. No differences were found in an analysis of early-stage disease.

Patients with metastatic invasive lobular carcinoma were significantly underrepresented in clinical trials of breast cancer, which may be due to extensive application of RECIST criteria. The fact that fewer women with these cancers are in trials is notable. It is hard to know if the finding is actionable.

Poster Session: Care Delivery and Regulatory Policy
Available Starting on Friday, June 4, 2021; 9:00 EDT

1570 Feasibility of integrating the Outcomes4Me smartphone navigation application into the care of breast cancer patients (FIONA). SJ Isakoff, M Said, AH Kwak, et al

Take-Home Message

In this pilot study, the study authors evaluated the feasibility of implementing the smartphone app Outcomes4Me, intended to improve patient engagement in the setting of breast cancer. Patients diagnosed with breast cancer (stage I–IV) were provided with the app and asked to complete a survey at baseline and at a 12-week follow-up visit. In total, 58% of 107 enrolled patients (median age, 53; 90% White, 4% Black, 3% Asian) engaged with the app at least three times over study follow-up (average days of engagement, 5.5). App features reported as being most helpful were background about a user’s breast cancer (76%), information about treatment options (74%), newsfeed about user’s breast cancer (70%), symptom tracking (65%), and clinical trial information (65%).

The Outcomes4Me smartphone app is feasible to implement and may assist patients diagnosed with breast cancer to engage in complex decisions about their care. The use of cell phone technology to improve patient education and engagement is a very hot topic, with implications for patients at all economic levels.

Oral Abstract Session: Health Services Research and Quality Improvement
Available Starting on Friday, June 4, 2021; 9:00 EDT

6500 Racial and ethnic disparities among patients with breast cancer and COVID-19. G Nagaraj, MK Accordino, B French, et al

Take-Home Message

Using data from the COVID-19 and Cancer Consortium registry, investigators evaluated racial differences in clinical outcomes among patients with breast cancer who were also infected with COVID-19. Compared with non-Hispanic White women (n = 575), Hispanic women (n = 183) were significantly younger, less likely to have ever smoked, and more likely to have active breast cancer and recent anti-cancer therapy. In this same comparison, non-Hispanic Black women (n = 243) had higher rates of obesity and a more severe presentation of COVID-19. Rates of hospital admission for COVID-19 were significantly higher among Black women compared with White and Hispanic women (White, 34%; Black, 49%; Hispanic, 34%; P <.001). Similar trends were observed for mechanical ventilation (White, 3%; Black, 9%; Hispanic, 5%; P = .002) and 30-day mortality (White, 6%; Black, 9%; Hispanic, 4%; P = .043).

Findings from this large, registry-based study revealed significantly worse COVID-19 outcomes among Black women with breast cancer compared with their White and Hispanic counterparts, which may be attributable to more frequent comorbidities and a more severe COVID-19 presentation. The higher frequency of active breast cancer observed among Hispanic women did not translate to poorer COVID-19 outcomes in this group.

6508 Reducing racial disparities in time to breast cancer diagnosis: Impact of immediate screening mammogram reads during the COVID pandemic. J Achibiri, BN Dontchos, S Mercaldo, et al

Take-Home Message

Study authors evaluated the effect of immediate-read screening mammography, implemented in response to the COVID-19 pandemic, on racial/ethnic disparities in the time to diagnostic imaging for breast cancer. Multivariable analysis was conducted using data from consecutive patients undergoing mammography screening during the period before (6/1/19–10/31/19; n = 8222) and after implementation (6/1/2020–10/31/2020; n = 7235) of immediate-read screening. The median time to finalize mammography reports was significantly shorter after (4 minutes) compared with before program implementation (61 minutes). Rates of abnormal interpretation were lower after compared with before implementation (5.0% vs 6.3%). Before implementation, non-White patients were significantly less likely than White patients to have same-day diagnostic imaging after an abnormal screening exam (aOR, 0.28), but not after implementation. Rates of cancer detection and the positive predictive value of mammography were unaffected by immediate-read screening.

Study findings suggest that immediate-read screening mammography reduces racial/ethnic disparities in access to diagnostic mammography, without lowering the quality of mammography.

Poster Discussion Session: Health Services Research and Quality Improvement
Available Starting on Friday, June 4, 2021; 9:00 EDT

6516 Disparities in surveillance imaging after breast conserving surgery for primary DCIS. D Byng, VP Retel, W van Harten, et al

Take-Home Message

Study authors assessed racial/ethnic differences in adherence to guidelines for surveillance screening following treatment for ductal carcinoma in situ (DCIS). Trends in asymptomatic visits for breast imaging were evaluated in a sample of 12,559 women diagnosed with screen-detected, biopsy-confirmed DCIS in the US (median age, 60 years; median follow-up, 5.6 years). Surveillance imaging within the guideline recommendation of a period of 6 to 18 months after diagnosis was done in 65% of women who received breast-conserving surgery (BCS) and 79.7% of women who received BCS plus radiotherapy. Consistent annual screening was done in 38.7% and 54.0% who received BCS and BCS plus radiotherapy, respectively. Surveillance imaging after treatment of primary DCIS was less common in non-Hispanic Black women (OR, 0.85) and Hispanic women (OR, 0.86) compared with non-Hispanic White women. Surveillance imaging after primary DCIS was also less common among women without private insurance than among women with private insurance. Use of surveillance screening was not associated with prognostic tumor features.

Adherence to guideline recommendations for screening following treatment of primary DCIS is low in the US, particularly among Black and Hispanic women and women without private health insurance.

Poster Session: Health Services Research and Quality Improvement
Available Starting on Friday, June 4, 2021; 9:00 EDT

6521 Socioeconomic status variables contribute to the disparities in female triple negative breast cancer outcome in the United States, 2011-2015: A population study based on NCI Surveillance, Epidemiology and End Results (SEER) database. Z Wang, Y Dong, Z Lu, et al

Take-Home Message

SEER registry data were used to evaluate the effect of race and socioeconomic status on survival trends in 22,434 women diagnosed with triple-negative breast cancer (TNBC) from 2011 to 2015. In multivariable analysis, TNBC cause-specific mortality was found to be significantly higher in women with no insurance (HR, 1.60; reference is private insurance) or Medicaid (HR, 1.29) and in women living in a county with a high poverty rate compared with women living in a county with the lowest poverty rate (HR, 1.25). Being single or widowed was significantly associated with lower TNBC cause-specific mortality compared with being married (OR, 0.86). A significant interaction between race and insurance status was identified: Black women who received Medicaid had better survival compared with non-Hispanic White women who received Medicaid (HR, 0.86).

Study findings suggest that disparities in TNBC cause-specific mortality may be driven in part by inequities in insurance coverage as well as by poverty.

6562 Impact of disruptions in breast cancer control due to the COVID-19 pandemic on breast cancer mortality in the United States: Estimates from collaborative simulation modeling. O Alagoz, KP Lowry, AW Kurian, et al

Take-Home Message

The study authors used projection models from the Cancer Intervention and Surveillance Modeling Network (CISNET) to estimate excess breast cancer mortality due to COVID-19–related interruptions in usual screening and treatment services. The models projected about 2500 excess breast cancer deaths by 2030, corresponding to an 0.6% increase over mortality estimates in the absence of COVID-19. Projected excess deaths were attributed to reduced screening (n = 1297), delayed diagnosis of symptomatic disease (n = 1325), and reduced chemotherapy for early-stage disease (n = 207). In sensitivity analysis, excess mortality was projected to double if interruptions of clinical services for breast cancer lasted for 12 months.

Projected excess mortality from COVID-19–related interruptions in normal breast cancer screening and treatment is minimal but could increase rapidly if interruptions are prolonged. We don’t yet know if delays in mammographic screening in the US will translate to either advanced stage at presentation or worsened oncologic outcomes. The modeling studies are important as we follow-up on this going into the post-pandemic period.

Poster Session: Prevention, Risk Reduction, and Hereditary Cancer
Available Starting on Friday, June 4, 2021; 9:00 EDT

10543 Analysis of breast cancer screening results in urban areas of Henan Province. G Lan-Wei

Take-Home Message

This study analyzed the results of breast cancer screening in 13,760 women living in urban Henan province, China, (age range, 40–75 years). A breast ultrasound examination was conducted in all women, and mammography was conducted in women 45 years or older. Breast lesions classified as BI-RADS 3 were defined as suspicious, and lesions classified as BI-RADS ≥4 were deemed positive. Suspicious lesions were identified in 23.40% of women and positive lesions in 2.55% of women; breast cancer was confirmed in 0.30% of women. Detection of positive lesions and breast cancer increased with age. Suspicious lesions were most common among women 45 to 49 years old (27.79%), positive lesions were most common among women 50 to 54 years old (2.98%), and detection of breast cancer was most common among women 65 to 69 years old. The rate of breast cancer detection was significantly higher in examinations that combined ultrasound with mammography (2.95%) compared with those using breast ultrasound alone (1.99%) or mammography alone (1.25%).

Combined ultrasound and mammography significantly increased the detection of breast cancer compared with either modality alone and should be considered in routine screening. While the study focuses on increased detection, the question is — at what cost to the patient in terms of unnecessary work-ups?

10555 Adverse consequences of the COVID-19 pandemic on breast cancer stage distribution and breast cancer disparities. GA Fasano, Y Chen, S Bayard, et al

Take-Home Message

The study authors analyzed data from 894 patients diagnosed with breast cancer from January 1, 2019, to December 31, 2020, in New York City, to evaluate the effect of a 3-month COVID-19–related hiatus in screening mammography on patient outcomes. Screen detection of cancer was significantly higher before the hiatus (65.5%) compared with during (49.2%) and after (54.7%) the hiatus. Similarly, the detection of small tumors (<1 cm) was more common before (41.9%) compared with after the hiatus (31.7%). Before the hiatus, screen-detected cancer was significantly more common among White patients compared with African American patients (69.1% vs 56.1%) and more common among White patients compared with Hispanic and Asian patients, but not significantly so. After the hiatus, screen-detected cancer was significantly more common among White patients (63.0%) than among all racial groups (African American, 48.1%; Asian, 33.3%; Hispanic, 40%). Similar trends were observed for the detection of small tumors.

Study findings suggest that, in New York City, the 3-month hiatus in routine breast cancer screening during the COVID-19 pandemic led to a more advanced stage of disease at diagnosis and exacerbated racial disparities in access to breast screening services.

10562 Factors associated with breast self-examination in Mexican young women with breast cancer. AB Gaitan, B Vaca-Cartagena, AS Ferrigno, et al

Take-Home Message

To identify factors associated with breast self-examination (BSE), these investigators surveyed young women newly diagnosed with breast cancer at a referral center in Mexico. The study included 554 women (median age at diagnosis, 36 years); an appreciable proportion of women were diagnosed at clinical stage III (32%) and IV (10%). Most women (80%) reported that they practiced BSE, but only 50% of women did so on a monthly basis. Practicing BSE was significantly associated with having at least a high school education (RR, 1.28), as well as early breast cancer stage (stage 0–II) at diagnosis. Patients with private insurance were also significantly more likely to be diagnosed with early-stage cancer compared with patients with public or no insurance (80% vs 56%).

Consistent practice of BSE supports diagnosis of breast cancer at an earlier stage but is not practiced by many younger women in Mexico. Consideration should be given to public health interventions to increase awareness of BSE among this high-risk population.

borstkanker, ASCO 2021, aanbevolen abstracten