Impact of obesity in postmenopausal early breast cancer patients receiving frontline adjuvant aromatase inhibitors.

e11020 Background: Aromatase inhibitors (AIs), anastrozole (ANA) and letrozole (LET), have been shown to be more effective than tamoxifen in the adjuvant treatment of postmenopausal hormone receptor positive breast cancer. However, data from preclinical studies and subgroup analyses of some major clinical trials suggest differring efficacy among AIs. Yet the best clinical choice is still not very clear. This retrospective study aims at comparing the results of treatment with either AI among different subgroups of patients, especially among the obese patients. Methods: Between 2006-2011, 335 women with stage I to IIIC hormone receptor positive postmenopausal breast cancer treated with either ANA or LET as adjuvant treatment were included. Body mass index (BMI), estrogen and progesterone receptor (ER and PR) and HER-2 status at the time of diagnosis were recorded. Patients were grouped as BMI ≤ 30 and BMI > 30. The Kaplan-Meier survival estimates were calculated. Subgroups were compared with the log rank te...