Association of Overweight with Breast Cancer Survival

Abstract
The authors investigated the association between overweight at the time of or soon after cancer diagnosis and survival in a cohort of 1,455 breast cancer patients aged 25–64 years. The patients were recruited into the Shanghai Breast Cancer Study (Shanghai, China), a population-based case-control study, between August 1996 and March 1998. The median follow-up time for this cohort was 5.1 years (1996–2002) after breast cancer diagnosis, and 240 deaths were identified. Being overweight at cancer diagnosis or soon afterward, as measured by body mass index (BMI; weight (kg)/height (m)2), was associated with poorer overall survival and disease-free survival. Five-year survival rates were 86.5%, 83.8%, and 80.1% for subjects whose BMIs were p = 0.02); the corresponding 5-year disease-free survival rates were 81.9%, 78.1%, and 76.6% (p = 0.05). The inverse association between BMI and survival persisted after adjustment for age at diagnosis and other known prognostic factors for breast cancer, including disease stage. The authors found neither waist:hip ratio nor waist circumference to be independently associated with overall survival or disease-free survival. These results suggest that excess weight may be an independent predictor of breast cancer survival among Chinese women.