Over 50% of women with breast cancer are overweight or obese. Obese breast cancer survivors have a significantly higher risk of breast cancer-specific and overall mortality compared with non-obese survivors. Weight loss post-diagnosis may improve breast cancer outcomes, however very few breast cancer patients are advised to manage their weight despite recommendations from major international cancer organisations.
We conducted a feasibility trial to assess the acceptability and efficacy of a telephone-delivered weight loss program for women following treatment for breast cancer, on the primary outcome of weight loss and secondary outcomes including quality of life and treatment-related side-effects.
Women diagnosed with stage I-III breast cancer were recruited from an Australian State-based Cancer Registry. Participants were randomised to the weight loss intervention (posted intervention materials and up to 16 telephone calls from a dietitian over 6 months) or usual care. Weight was measured at baseline and 6-months. Secondary outcomes included quality of life (SF-36), fatigue (FACIT-Fatigue), body image (BIRS Total Score) and lymphoedema (bioelectrical impedance spectroscopy). Linear regression analyses adjusted for baseline values and confounding variables, using multiple imputation for missing data (82% retention at 6-months).
Ninety women (mean±SD BMI: 31.0±4.3kg/m2; age: 55.3±8.7 years; median 16 months post-diagnosis [min-max: 12-21]) participated. A significant intervention effect was observed for percentage weight loss at 6-months (intervention – usual care [95% CI]: -4.4 [-6.4, -2.4]%). No statistically significant intervention effects were observed for the secondary outcomes listed; however the mean intervention effect on the mental health component of quality of life was considered clinically meaningful (0.4 [95%CI -0.6, 1.6]). No serious adverse events were reported.
This study showed that weight loss is safe and feasible to achieve in women following treatment for breast cancer. More research is needed to understand the impact of weight loss on breast cancer-related outcomes.