title: Bisphosphonates and breast cancer prevention.
abstract: Bisphosphonates are commonly used in patients with breast cancer to reduce skeletal-related events in metastatic disease and to mitigate bone loss associated with cancer therapy in early stage disease. In addition, adjuvant breast cancer trials evaluating the oral bisphosphonate clodronate suggested a reduction in cancer recurrence, but the findings were mixed, with 2 positive and 1 negative report. In the Austrian Breast and Colorectal Cancer Study Group (ABCSG) 12 study, adding the intravenous bisphosphonate zoledronic acid to endocrine therapy in premenopausal breast cancer patients significantly prolonged disease-free survival versus endocrine therapy alone (hazard ratio = 0.68; p = 0.008) at 62 months, and reduced local, regional, and distant recurrences. Clinical trial findings from other adjuvant trials (Z-FAST, ZO-FAST), neoadjuvant studies, and studies involving disseminated tumor cells (DTCs) are generally supportive of the ABCSG-12 conclusion, and recent data from AZURE suggest the importance of menopausal status. Preclinical studies provide data on the mechanisms of action that could mediate bisphosphonate direct and indirect anti-cancer effects. Recently, several observational studies (2 cohort studies and 2 case-control analyses) have associated oral bisphosphonate use with a lower breast cancer incidence. Such reports require cautious interpretation because confounding by indication is an issue: bisphosphonates are prescribed for women with low bone mineral density, and women with low bone density are at decreased breast cancer risk.
authors.affiliation: Los Angeles Biomedical Research Institute, Harbor-UCLA Medical Center, 1124 W. Carson St. Torrance, CA 90502, USA. rchlebowski@gmail.com
authors.forename: Rowan T
authors.initials: RT
authors.lastname: Chlebowski
authors.forename: Nananda
authors.initials: N
authors.lastname: Col
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology / Q000627:therapeutic use*; D050071:Bone Density Conservation Agents / Q000494:pharmacology / Q000627:therapeutic use*; D001940:Breast / Q000187:drug effects / Q000473:pathology; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000473:pathology / Q000517:prevention & control; D017024:Chemotherapy, Adjuvant; D004164:Diphosphonates / Q000494:pharmacology / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology / Q000627:therapeutic use; D000077211:Zoledronic Acid
chemical_list: D000970:Antineoplastic Agents; D050071:Bone Density Conservation Agents; D004164:Diphosphonates; D007093:Imidazoles; D000077211:Zoledronic Acid