Department of Gynecology and Obstetrics, University of Heidelberg, Heidelberg, Germany.

BACKGROUND: Adding oral clodronate to postoperative adjuvant breast cancer therapy significantly improves disease-free survival (DFS) and overall survival (OS). Long-term follow-up data from the prospective, randomized, controlled study are reported.

PATIENTS AND METHODS: Patients with primary breast cancer received clodronate 1600 mg/day for 2 years or no treatment along with standard adjuvant breast cancer treatment.

RESULTS: Analysis of 290 of 302 patients demonstrated that a significant improvement in OS was maintained in the clodronate group at a median follow-up of 103 +/- 12 months; 20.4% of patients in the clodronate group versus 40.7% of control group patients (P = 0.04) died during the 8.5 years following primary surgical therapy. Significant reductions in the incidence of bony and visceral metastases and improvement in duration of DFS at 36- and 55-month follow-up periods were no longer seen with clodronate.

CONCLUSION: These long-term survival data extend the survival advantage reported in previous studies with oral clodronate in breast cancer.

PMID: 18664560 [PubMed - as supplied by publisher]

1: Breast Cancer Res. 2006;8(2):R13. Epub 2006 Mar 15. Links

Erratum in:

Breast Cancer Res. 2006;8(3):406.

Reduction in bone relapse and improved survival with oral clodronate for adjuvant treatment of operable breast cancer .

Parkside Oncology, London, UK. hdummer@parkside-hospital.co.uk

INTRODUCTION: Experimental and clinical data show that the oral bisphosphonate clodronate (Bonefos) can inhibit tumor-induced osteoclastic bone resorption. This randomized, double-blind, placebo-controlled, multicenter trial was designed to determine if the addition of oral clodronate to standard treatment for primary operable breast cancer could reduce the subsequent occurrence of bone metastases and thereby improve overall survival.

METHODS: 1,069 patients with primary operable stage I-III breast cancer were randomized to receive oral clodronate (1,600 mg/day) or placebo for 2 years, in conjunction with standard treatment for primary breast cancer including surgery, radiotherapy, adjuvant chemotherapy, and/or tamoxifen. All patients were assessed for bone metastases at two and five years and additionally when clinically indicated. Survival status was determined as of the close of the study on 30 June 2000 with a median follow up of 5.6 years. The treatment arms were compared using the unstratified log-rank test. Hazard ratios (HRs) with 95% confidence intervals were calculated.

RESULTS: Oral clodronate significantly reduced the risk of bone metastases in all patients over the 5 year study period (51 patients versus 73 patients with placebo; HR = 0.692, P = 0.043); the difference was also statistically significant over the 2 year medication period (19 patients versus 35 patients with placebo; HR = 0.546, P = 0.031). These differences were most pronounced in patients with stage II/III disease (39 patients versus 64 patients with placebo, HR = 0.592, P = 0.009 over 5 years; 16 patients versus 32 patients with placebo, HR= 0.496, P = 0.020 over 2 years). Survival data also favoured the clodronate arm (HR for all patients = 0.768, P = 0.048; HR for stage II/III disease = 0.743, P = 0.041), although this was not significant due to multiple analyses. Oral clodronate was well tolerated, with mild-to-moderate diarrhoea being the most frequently reported adverse event.

CONCLUSION: These results confirm that oral clodronate will significantly improve the 5 year bone relapse free survival when used as a supplementary adjuvant treatment for patients receiving standard treatment for primary operable breast cancer.

PMID: 16542503 [PubMed - indexed for MEDLINE]

PMCID: PMC1557723