The oncologist
-
Randomized Controlled Trial Comparative Study
Integrated analysis of zoledronic acid for prevention of aromatase inhibitor-associated bone loss in postmenopausal women with early breast cancer receiving adjuvant letrozole.
The interim (12-month) results of two similarly designed, ongoing studies (the Zometa-Femara Adjuvant Synergy Trials [Z-FAST and ZO-FAST]) suggest that zoledronic acid (4 mg intravenously every 6 months) when initiated with adjuvant letrozole increases bone mineral density (BMD) of the lumbar spine (LS) in postmenopausal women with early-stage breast cancer compared with patients who receive zoledronic acid only when bone loss became clinically significant or a fragility fracture occurred. ⋯ The results of this analysis strengthen the statistical validity of the preliminary results of the Z-FAST and ZO-FAST studies, showing that upfront zoledronic acid prevents aromatase inhibitor-associated bone loss more effectively than delayed-start zoledronic acid in postmenopausal women with early-stage breast cancer receiving letrozole. Additionally, disease recurrence appears to be lower with upfront zoledronic acid, but further follow-up is needed to confirm these interim results.