Role of obesity on the efficacy of exemestane plus ovarian suppression in hormone receptor-positive premenopausal breast cancer.

Abstract

10.2217/FON.15.6 © 2015 Future Medicine Ltd Antihormonal treatment with aromatase inhibitors or tamoxifen are the corner stone treatment options in the adjuvant treatment of hormone receptor-positive breast cancer. In last decade, resulted randomized trials showed that aromatase inhibitors provide more benefit than tamoxifen in hormone receptor-positive postmenopausal breast cancer [1]. Due to the significant diseasefree survival (DFS) and lower recurrences benefit with both upfront aromatase inhibitors for 5 years or sequential therapy with tamoxifen for 2–3 years followed by aromatase inhibitors in early breast cancer, aromatase inhibitors have been accepted as first line endocrine treatment in hormone receptor-positive postmenopausal breast cancer [2]. Obesity and overweight patients have independent risk factor for the development of breast cancer and the outcome of breast cancer was significantly poor in obese patients compared with nonobese patients especially in postmenopausal women [3,4]. Overweight or obese postmenopausal women exhibit a threefold increased risk for developing breast cancer compared with normal weight postmenopausal women [5,6]. Weight gain after diagnosis of breast cancer is also associated with decreased survival and less favorable clinical characteristics such as greater tumor burden, higher grade and poorer prognosis [4,7]. Obesity has been accepted the source of abnormal expression of aromatase enzyme in the breast that leads to increase local estrogen production and predisposition to developing breast cancer and the risk of recurrence has been increased significantly compared with nonobese patients especially in postmenopausal breast cancer patients [8]. In contrast to postmenopausal patients, an increased BMI is associated with a lower risk of breast cancer in premenopausal women and in the pooled analysis of seven prospective cohort studies that comprise 337,819 women and 4385 invasive breast cancer patients showed that BMI ≥31 kg/m were 46% less likely to develop breast cancer than those with a BMI <21 kg/m [9]. Despite the risk of breast cancer significantly decreased in premenopausal breast cancer patients, the outcome was also poor in obese premenopausal and perimenopausal breast cancer patients. In COMMENTARY