Bisphosphonates in adjuvant setting for breast cancer: a review of the meta-analysis of bisphosphonates' effects on breast cancer recurrence presented in December 2013 at San Antonio Breast Conference

Purpose of review Bisphosphonate therapy has been used as standard of care for patients with metastatic bone disease. As bisphosphonate had demonstrated antitumor effects in preclinical studies, it was natural to advance to the development of large phase 3 trials that would test the activity of bisphosphonate in the adjuvant setting. Surprisingly, the results of adjuvant breast cancer trials have shown either modest or contradictory effects. One of the most consistent results across the latest reports on this issue is that bisphosphonate shows benefit in the prevention of distant relapses in breast cancer women after menopause, but not before. We sought to comment on the most recent studies and to reflect on the possible practical recommendations for the use of bisphosphonate in this setting. Recent findings In the last San Antonio Breast Cancer Conference, the Early Breast Cancer Trialists' Collaborative Group's Bisphosphonate Working Group presented a meta-analysis of individual patient data from randomized trials. The main conclusions of this presentation were that all bisphosphonates (not only nitrogen-containing bisphosphonates) can decrease bone recurrence in postmenopausal women with early breast cancer. Summary The benefit of bisphosphonate use in an adjuvant setting is significant only in postmenopausal women. Further investigation into factors influencing the response to bisphosphonate treatment is needed.