Aromatase inhibitor-induced bone mineral loss and its prevention by bisphosphonate administration in postmenopausal breast cancer patients.
OBJECTIVE
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/Ht(2)) 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.


CONCLUSIONS
AI carries a potential risk of bone mineral loss despite the short therapy duration. Bisphosphonate has a preventive effect on this loss.
Yonehara
Yukie
Y
Department of Obstetrics and Gynecology, Kagoshima University Medical and Dental Hospital, Sakuragaoka, Kagoshima, Japan.
Iwamoto
Ichiro
I
Kosha
Shoichiro
S
Rai
Yoshiaki
Y
Sagara
Yoshiatsu
Y
Douchi
Tsutomu
T
D000368:Aged; D000077384:Anastrozole; D047072:Aromatase Inhibitors / Q000009:adverse effects* / Q000627:therapeutic use; D015519:Bone Density / Q000187:drug effects; D050071:Bone Density Conservation Agents / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy*; D004347:Drug Interactions; D012968:Etidronic Acid / Q000031:analogs & derivatives* / Q000627:therapeutic use; D005260:Female; D006801:Humans; D008875:Middle Aged; D009570:Nitriles / Q000009:adverse effects* / Q000627:therapeutic use; D010024:Osteoporosis / Q000139:chemically induced / Q000473:pathology / Q000517:prevention & control*; D017698:Postmenopause; D000068296:Risedronic Acid; D014230:Triazoles / Q000009:adverse effects* / Q000627:therapeutic use
D047072:Aromatase Inhibitors; D050071:Bone Density Conservation Agents; D009570:Nitriles; D014230:Triazoles; D000077384:Anastrozole; D000068296:Risedronic Acid; D012968:Etidronic Acid