Effect of Zoledronic Acid Therapy on Aromatase Inhibitor Induced Bone Loss
Neeraj Kumar Agarwal, Ved Prakash, Manoj Pandey and Uday P Shahi
World Journal of Surgical Medical and Radiation Oncology 2015, 4:5
In postmenopausal hormone responsive early breast cancer, adjuvant aromatase inhibitor (AI) therapy improves disease free survival; however, it also produces bone loss. There are currently no approved modalities for prevention or treatment of this bone loss.
This study was carried out to study the effects of zoledronic acid on aromatase-inhibitors-induced bone loss (AIBL) in postmenopausal hormone-receptor-positive early-breast-cancer in Indian patients.
The study included 20 postmenopausal hormone receptor positive early breast cancer (stage I-IIIA) patients. All patients had undergone primary surgery, did not have recurrent or metastatic disease and were receiving adjuvant aromatase inhibitor therapy for variable duration. Lumbar spine BMD (LSBMD) and serum bone turnover markers [C-telopeptide crosslinks (CTX) and alkaline phosphatase (ALP) ] were measured at baseline and repeated after zoledronic acid infusion (bone turnover markers at 6 months and LSBMD at 12 months). The primary endpoint was the average percentage change in bone turnover markers at 6 months while the secondary endpoint was average percentage change in LSBMD after one year from baseline.
The mean age of the patients was 60.15±4.29 years. Six months after zoledronic acid, mean serum CTX level decreased from 0.76±0.40 ng/ml to 0.49± 0.27 ng/ml (∆= -35%; p <0.001). Similarly ALP decreased from 194.75±24.44 IU/L to136.20±12.12 IU/L (∆= -30%; p <0.001). At one year follow-up, LSBMD could be done in 7 patients; the mean LS T-score increased from -2.75±0.37 to -2.64±0.35 (p-value = 0.01; ∆= 4.6%), and mean LS BMD increased from 0.788±0.041 gm/cm2 to 0.816±0.032 gm/cm2 (p-value = 0.016; ∆= 3.6%). There were no adverse events recorded during the study.
The zoledronic acid is safe and effective for the treatment of AIBL in postmenopausal hormone responsive early breast cancer patients. This can be potentially used for prevention of AIBL.