21 juli 2010: Bron: J Clin Oncol. Published online June 21, 2010

Dagelijks gebruik van bisphosfonaten zoals Zometa lijken het risico op hormoongevoelige invasieve borstkanker met ca. 30% te kunnen verminderen voor vrouwen na de overgang. Dit blijkt uit drie onafhankelijk van elkaar uitgevoerde retropostpectieve studies onder grote groepen vrouwen. Zie hier de abstracten van de studies waarvan de resultaten voor zich spreken. Zie ook artikel in Medscape hierover. Opmerking: alle onderzoekers betrokken bij deze studie melden banden te hebben met de bedrijven die bisphosfonaten produceren.

J Clin Oncol. 2010 Jun 21. [Epub ahead of print]

Use of Bisphosphonates and Risk of Postmenopausal Breast Cancer.

Rennert G, Pinchev M, Rennert HS.

Carmel Medical Center and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology; and Clalit Health Services National Cancer Control Center, Haifa, Israel.

Abstract

PURPOSE Bisphosphonates are commonly used for the treatment of osteoporosis and for prevention and treatment of skeletal lesions due to malignancy. However, the association between the use of bisphosphonates and the risk of developing breast cancer has not been reported.

PATIENTS AND METHODS The Breast Cancer in Northern Israel Study is a population-based case-control study in northern Israel of patients with breast cancer and age-, clinic-, and ethnic-group matched controls. Use of bisphosphonates was assessed in 4,039 postmenopausal patients and controls, members of Clalit Health Services, using pharmacy records. Results The use of bisphosphonates for longer than 1 year before diagnosis, but not for shorter than 1 year, was associated with a significantly reduced relative risk of breast cancer (odds ratio , 0.61; 95% CI, 0.50 to 0.76). This association remained significant after adjustment for age, fruit, and vegetable consumption, sports activity, family history of breast cancer, ethnic group, body mass index, use of calcium supplements, hormone replacement therapy use, number of pregnancies, months of breast feeding, and age at first pregnancy (OR, 0.72; 95% CI, 0.57 to 0.90). Breast cancer risk did not change further if bisphosphonates were used for more years. Breast tumors identified in bisphosphonates users were more often estrogen receptor positive and less often poorly differentiated.

CONCLUSION The use of bisphosphonates for longer than 1 year was associated with a 28% relative reduction in the risk of postmenopausal breast cancer. Tumors developing under bisphosphonates treatment tended to have a favorable prognostic factors profile.

PMID: 20567021 [PubMed - as supplied by publisher]

J Clin Oncol. 2010 Jun 21. [Epub ahead of print]

Oral Bisphosphonate Use and Breast Cancer Incidence in Postmenopausal Women.

Chlebowski RT, Chen Z, Cauley JA, Anderson G, Rodabough RJ, McTiernan A, Lane DS, Manson JE, Snetselaar L, Yasmeen S, O'Sullivan MJ, Safford M, Hendrix SL, Wallace RB.

Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance; University of California at Davis, Sacramento, CA; University of Arizona, Tucson, AZ; University of Pittsburgh, Pittsburgh, PA; Fred Hutchinson Cancer Research Center, Seattle, WA; State University of New York, Stony Brook, NY; Brigham and Women's Hospital and Harvard Medical School, Boston, MA; University of Iowa; University of Iowa Hospitals and Clinics, Iowa City, IA; University of Miami, Miami, FL; University of Alabama School of Medicine, Birmingham, AL; and Wayne State University School of Medicine and Hutzel Hospital, Detroit, MI.

Abstract

PURPOSE Emerging clinical evidence suggests intravenous bisphosphonates may inhibit breast cancer while oral bisphosphonates have received limited evaluation regarding breast cancer influence.

PATIENTS AND METHODS The association between oral bisphosphonate use and invasive breast cancer was examined in postmenopausal women enrolled onto the Women's Health Initiative (WHI). We compared a published hip fracture prediction model, which did not incorporate bone mineral density (BMD), with total hip BMD in 10,418 WHI participants who had both determinations. To adjust for potential BMD difference based on bisphosphonate use, the hip fracture prediction score was included in multivariant analyses as a BMD surrogate. Results Of the 154,768 participants, 2,816 were oral bisphosphonate users at entry (90% alendronate, 10% etidronate). As calculated hip fracture risk score was significantly associated with both BMD (regression line = 0.79 to 0.0478 log predicted fracture; P < .001; r = 0.43) and breast cancer incidence (P = .03), this variable was incorporated into regression analyses to adjust for BMD difference between users and nonusers of bisphopshonate. After 7.8 mean years of follow-up (standard deviation, 1.7), invasive breast cancer incidence was lower in bisphosphonate users (hazard ratio , 0.68; 95% CI, 0.52 to 0.88; P < .01) as was incidence of estrogen receptor (ER)-positive invasive cancers (HR, 0.70; 95% CI, 0.52 to 0.94, P = .02). A similar but not significant trend was seen for ER-negative invasive cancers. The incidence of ductal carcinoma in situ was higher in bisphosphonate users (HR, 1.58; 95% CI, 1.08 to 2.31; P = .02).

CONCLUSION Oral bisphosphonate use was associated with significantly lower invasive breast cancer incidence, suggesting bisphosphonates may have inhibiting effects on breast cancer.

PMID: 20567009 [PubMed - as supplied by publisher]

preventie, borstkanker, Zometa, bisphosfonaten