The Influence Of Obesity For Hormone Receptor-positive Postmenopausal Breast Cancer Patients Using Aromatase Inhibitors

BACKGROUNDThe aromatase in postmenopausal breast cancer patients mainly arises from fatty tissue. Obesity may increasingly induce aromatase expression in breast cancer patients with postmenopausal status. Aromatase inhibitor could indirectly stop estrogen from stimulating cell proliferation by suppressing aromatase enzyme. Therefore, we performed a retrospective research to investigate the relationship between obesity and aromatase inhibitor in hormone receptor-positive postmenopausal breast cancer patient.METHODSA total of209newly diagnosed breast caner patients with hormone receptor-positive breast cancer who are postmenopausal and non-metastatic in Sir Run Run Shaw Hospital from August2001to December2012were enrolled. Patients with BMI ranging between18.5kg/m2to24.9kg/m2were considered as normal weight group(n=121), patients with a BMI ranging≥25kg/m2were grouped as overweight and obese patients(n=88). Compare DFS and OS in each group by Kaplan-Meier survival analysis.RESULTSIn both groups, most baseline conditions were similar, including pathologic subtypes, surgery types and treatment history in radiotherapy and chemotherapy. However, the tumor size in normal weight group was slightly smaller than that of overweight group (p=0.022), Tl accounted for62.0%VS44.3%respectively. In normal weight patients disease-free survival(DFS) rate was92%and89%, whereas in overweight and obese patients DFS was94%and90%in the first and third years, respectively(p=0.873). Five year survival rate in normal weight group was90%, whereas in overweight group was96%.CONCLUSIONL1. Our results show that BMI seems to negatively affect aromatase inhibitors in postmenopausal hormone-receptor positive breast cancer patients.2. Normal weight patients seem to have smaller tumor-sizes than overweight or obese patients.