A new study has reported that obesity does not reduce survival in women with triple negative breast cancer. Triple negative breast cancer is a subtype of breast cancer that is estrogen receptor negative (ER-), progesterone receptor negative (PR-), and human epidermal growth factor receptor 2 (HER2) negative. The study was designed to investigate the prognostic effects of body mass index (BMI) in patients with triple negative breast cancer. Obesity is known to be associated with poorer outcomes in those with hormone receptor positive breast cancer. However, this association has not been established for women with triple negative breast cancer.

The study included 418 women with triple negative breast cancer treated between July 1996 and July 2010. A total of 124 (29.7%) participants were classified as normal/underweight (BMI ≤ 24.9 kg/m2 ), 130 (31.1%) were overweight (BMI from 25 to 29.9 kg/m2 ), and 164 (39.2%) were obese (BMI ≥ 30 kg/m2). Recurrence-free survival and overall survival were evaluated in relation to BMI after controlling for clinically significant factors.

There were 105 breast cancer recurrences and 87 deaths during the study follow-up period (median 37.2 months). Obese patients were not found to have poorer recurrence-free survival or overall survival than normal/underweight patients. Treatment with chemotherapy and ductal breast cancer type were found to be associated with more favorable overall survival, whereas stage III disease and increasing tumor size were associated with worse overall survival. The authors conclude that they found no significant relation between obesity and recurrence-free survival or overall survival in women with triple negative breast cancer after controlling for other variables known to be associated with breast cancer prognosis.

Please see our articles on triple negative breast cancer prognosis and what triple negative patients and survivors should eat for more information on triple negative breast cancer.