Weight gain in breast cancer patients: Tamoxifen versus anastrazole
10544 Background: Weight gain is a common complaint among breast cancer patients, especially those taking tamoxifen. Aromatase inhibitors have been increasingly used in postmenopausal breast cancer patients, and are generally thought to have a more tolerable side-effect profile than selective estrogen receptor modulators (SERM’s). This study specifically addresses weight gain in patients on the SERM, tamoxifen, compared to patients on the aromatase inhibitor, anastrazole. Methods: Ninety-six outpatients with primary breast cancer of any stage received standard doses of adjuvant hormonal therapy. Seventy received tamoxifen (Group T) and 26 anastrazole (Group A). The nursing staff in the clinic weighed all patients at the time of diagnosis, at start of chemotherapy (if received), at start of hormone therapy, and at 3 month intervals for 12 months after starting hormone therapy. Data were gathered in a retrospective manner. Results: Demographic variables were compared between the two groups. In all patients, it was noted that increasing age was correlated with greater weight gain at 3 months after starting hormone therapy (p = 0.0257), but not at any other intervals. No other variables were significantly correlated with weight gain. In Group T, mean weight gain was clinically (>1.8 kgs) and statistically significant at 9 and 12 months (p = 0.0137, p = 0.0003). In Group A, mean weight gain was not clinically significant at any point. Using the Wilcoxon two-sample tests to compare groups T and A, it was shown that there was no statistically significant difference in weight gain between the two groups at any interval (see table). Conclusions: These results are consistent with previous studies that show significant weight gain in breast cancer patients on tamoxifen. This study failed to show a statistically significant difference in weight gain between patients on tamoxifen and patients on anastrazole. Group A did not have statistically significant weight gain at any interval after starting hormone therapy. [Table: see text] No significant financial relationships to disclose.