Breast cancer survivors have previously been reported to experience weight gains after initial cancer diagnosis. In this prospective study of breast cancer survivors over a 36-month period, the objectives were to determine the changes in body mass index (BMI) and weight after initial diagnosis and to determine potential associated factors.
Chinese women with newly diagnosed early-stage breast cancer were recruited. Individual patients had their height measured at W0. Their weight and BMI were determined at breast cancer diagnosis (W0) and at 36-month follow-up (W1). Socio-demographic, clinical and lifestyle factors were recorded. Analyses were conducted to determine potential associated factors with weight change.
1133 patients were studied. The mean age at diagnosis was 52 years; 602 patients were premenopausal at breast cancer diagnosis. The proportions of overweight and obese patients were 21.2% and 28.5%, respectively, at W0, and 21.7% and 30.9%, respectively, at W1. When compared to W0, assessments at W1 revealed that 29.0% of breast cancer survivors had weight change within ±2%, 19.7% had weight gain by 2-5% and 23.2% had weight gain >5%, while 28.1% had weight loss >2%. The median value of weight change between W0 and W1 was 0.6 kg (range: -19.6, 20.5). On univariate analysis, younger women, women who were premenopausal at T2, women who were underweight at diagnosis and those who did not receive adjuvant chemotherapy had more weight gain at 36-month post-diagnosis. Lifestyle factors, including smoking and alcohol, level of physical activity and energy intake, as well as other socio-demographic and clinical factors were not associated with weight change.
At 36-month follow-up, this prospective study revealed that the proportions of Chinese breast cancer survivors who were overweight and obese were relatively stable. Further, weight gain was uncommon among the studied population. Further studies are warranted to assess their long-term outcomes.
Clinical trial identification
Legal entity responsible for the study
Joint CUHK-NTEC Clinical Research Ethics Committee and the KWC Research Ethics Committee.
World Cancer Research Fund International (Grant Number WCRF 2010/249 and WCRF 2014/1197).
All authors have declared no conflicts of interest.