Aromatase inhibitor-induced bone mineral loss and its prevention by bisphosphonate administration in postmenopausal breast cancer patients

• Published in: The Journal of obstetrics and gynaecology research Vol. 33; no. 5; pp. 696 - 699
• Main Authors: Yonehara, Yukie, Iwamoto, Ichiro, Kosha, Shoichiro, Rai, Yoshiaki, Sagara, Yoshiatsu, Douchi, Tsutomu
• Format: Journal Article
• Language: English
• Published: Melbourne, Australia Blackwell Publishing Asia 01.10.2007
• Subjects: Aged; aromatase inhibitor; Aromatase Inhibitors - adverse effects; Aromatase Inhibitors - therapeutic use; bisphosphonate; Bone Density - drug effects; Bone Density Conservation Agents - therapeutic use; bone mineral density; Breast Neoplasms - drug therapy; Drug Interactions; Etidronic Acid - analogs & derivatives; Etidronic Acid - therapeutic use; Female; Humans; Middle Aged; Nitriles - adverse effects; Nitriles - therapeutic use; Osteoporosis - chemically induced; Osteoporosis - pathology; Osteoporosis - prevention & control; postmenopausal breast cancer patient; Postmenopause; Risedronate Sodium; Triazoles - adverse effects; Triazoles - therapeutic use
• ISSN: 1341-8076; 1447-0756
• DOI: 10.1111/j.1447-0756.2007.00634.x

Aim:  To investigate aromatase inhibitor‐induced bone mineral loss and its prevention by bisphosphonate administration in postmenopausal breast cancer patients. Methods:  Subjects were 17 postmenopausal breast cancer patients (mean age, 63.3 ± 9.9 years) receiving non‐steroidal aromatase inhibitor (AI; anastrozole, 1 mg daily) only and 10 such patients (mean age, 65.0 ± 5.1 years) receiving AI + bisphosphonate (risedronate sodium, 2.5 mg daily) for 6 months. All of the subjects had undergone surgical resection and had positive estrogen receptor tumor status. Age, age at menopause, years since menopause, height, weight, and body mass index (Wt/Ht2) were recorded. Lumbar spine (L2–4) bone mineral density (BMD), T‐, and Z‐scores were assessed on dual‐energy X‐ray absorptiometry before and after therapy. Results:  In the AI‐only group BMD, T‐, and Z‐scores significantly decreased from the baseline during the 6‐month therapy period (P < 0.05). Mean decreases in L2–4 BMD and Z‐score were 2.5% and 3.0%, respectively. In the AI + bisphosphonate group, however, BMD, T‐, and Z‐scores significantly increased from the baseline values (P < 0.01). Mean increases in L2–4 BMD and Z‐score were 4.5% and 3.3%, respectively. Conclusion:  AI carries a potential risk of bone mineral loss despite the short therapy duration. Bisphosphonate has a preventive effect on this loss.