NPS BREAST CANCER JOURNAL
npj Breast Cancer (2020)6:6
Pamela J. Goodwin, Roanne J. Segal, Michael Vallis, Jennifer A. Ligibel, Gregory R. Pond, André Robidoux, Brian Findlay, Julie R. Gralow, Som D. Mukherjee, Mark Levine and Kathleen I. Pritchard
Obesity has been associated with poor breast cancer (BC) outcomes. We investigated whether a standardized, telephone-based weight loss lifestyle intervention in the adjuvant setting would impact BC outcomes. We conducted a multicenter trial randomizing women 1:1 to mail-based educational material alone (control) or combined with a standardized, telephone-based lifestyle intervention that focused on diet, physical activity, and behavior and involved 19 calls over 2 years to achieve up to 10% weight loss. In all, 338 (of 2150 planned) T1-3, N0-3, M0 hormone receptor positive BC patients with body mass index (BMI)≥24 kg/m2receiving adjuvant letrozole were randomized (enrolment ended due to funding loss). The primary outcome was disease-free survival (DFS); secondary outcome was Overall Survival (OS). At 8 years’ median follow-up, in a planned analysis, DFS and OS were compared using the Kaplan–Meier method. Baseline BMI and other characteristics were similar between study arms. In all, 22 of 171(12.9%) in the lifestyle intervention arm versus 30 of 167 (18.0%) in the education had DFS events; the hazard ratio (HR) was 0.71(95% confidence interval [CI]: 0.41–1.24,p=0.23). Although loss of funding reduced sample size, we view these hypothesis generating results as compatible with our hypothesis of a potential beneficial effect of a lifestyle intervention on DFS. They provide support for completion of ongoing randomized controlled trials of the effect of lifestyle interventions in BC outcomes.