Maintaining bone density in patients undergoing treatment for breast cancer: is there an adjuvant benefit?
Women undergoing treatment for breast cancer often experience a marked decrease in bone mineral density. This decrease is observed with chemotherapy as well as endocrine therapy and is more pronounced and rapid than normal postmenopausal bone loss. Pharmacologic intervention is, therefore, necessary in many cases to preserve bone health and prevent fractures. Many small studies have demonstrated that cancer therapy-induced bone loss (CTIBL) is effectively prevented by bone-targeted therapies, such as bisphosphonates and other inhibitors of bone resorption. Recently, several trials have confirmed the efficacy of bisphosphonates in the prevention of CTIBL in both premenopausal and postmenopausal women with early-stage breast cancer. In addition, concomitant treatment with zoledronic acid 4 mg every 6 months and standard adjuvant endocrine therapy has been reported to significantly improve disease-free survival and decrease disease recurrence in bone as well as other sites compared with standard therapy alone. Zoledronic acid treatment has also decreased residual tumor volume in the neoadjuvant setting. Furthermore, long-term follow-up of a single study in patients with bone marrow micrometastases from breast cancer revealed overall survival benefits for patients receiving clodronate 1600 mg/day compared with placebo; however, combined results from several trials of clodronate are inconclusive. Overall, a large body of evidence is accumulating to support the potential adjuvant benefits of bisphosphonates in the treatment of early-stage breast cancer. Results from ongoing studies are expected to further elucidate the benefits of bisphosphonates in maintaining bone health and improving clinical outcomes in patients with breast cancer.
Gnant
Michael
M
Department of Surgery, Medical University of Vienna, Vienna, Austria. michael.gnant@meduniwien.ac.at
Dubsky
Peter
P
Fitzal
Florian
F
Blaha
Peter
P
Schoppmann
Sebastian
S
Steger
Günther
G
Marth
Christian
C
Samonigg
Hellmut
H
Hüttner
Katharina
K
Fohler
Hannes
H
Ruecklinger
Ernst
E
Jakesz
Raimund
R
Greil
Richard
R
D000277:Adjuvants, Pharmaceutic / Q000627:therapeutic use*; D000970:Antineoplastic Agents / Q000009:adverse effects; D015519:Bone Density / Q000187:drug effects*; D050071:Bone Density Conservation Agents / Q000627:therapeutic use; D001851:Bone Diseases, Metabolic / Q000139:chemically induced / Q000188:drug therapy* / Q000503:physiopathology; D001943:Breast Neoplasms / Q000503:physiopathology / Q000628:therapy*; D002986:Clinical Trials as Topic; D004164:Diphosphonates / Q000627:therapeutic use; D005260:Female; D006801:Humans
D000277:Adjuvants, Pharmaceutic; D000970:Antineoplastic Agents; D050071:Bone Density Conservation Agents; D004164:Diphosphonates