Phase II Feasibility Study of a Weight Loss Intervention in Female Breast and Colorectal Cancer Survivors (SWOG S1008)

Objective: This study aimed to test the feasibility of a 12-month weight loss intervention using telephone-based counseling plus community-situated physical activity (PA) in female breast cancer (BC) and colorectal cancer (CRC) survivors. Methods: This multisite cooperative group study enrolled sedentary, female, postmenopausal BC and CRC survivors with BMI ≥ 25 kg/m² to receive 12-month fitness center memberships and telephone counseling encouraging 150 min/wk of PA and a 500-kcal/ddecrease in energy intake. Feasibility criteria included accrual, adherence, and retention. Target weight loss was ≥ 5%. Results: Among 25 BC survivors, median baseline BMI was 37.2 (range: 27.7-54.6), accrual occurred in 10 months, 60% and 28% met diet and exercise goals, 80% provided 12-month measures, and average weight loss was 7.6% (95% CI: −3.9%, 19.2%). Among 23 CRC survivors, median BMI was 31.8 (range: 26.4-48.7), accrual occurred in 24 months, 61% and 17% met diet and exercise goals, 87% provided measures, and average weight loss was 2.5% (95% CI: −8.2%, 13.3%). Conclusions: It is feasible to recruit and retain BC survivors in a cooperative group diet and PA weight loss trial. BC survivors achieved clinically meaningful weight loss but did not meet a priori adherence goals. In CRC survivors, recruitment was more difficult, and the intervention was less effective.