Life course evolution of body size and breast cancer survival in the E3N cohort

Abstract

Although adult obesity has been associated with poor breast cancer survival, data on adiposity at different periods in life and its lifelong evolution are scarce. Our aims were to assess the associations between breast cancer survival and body size during childhood, puberty, and early adulthood and body size trajectories from childhood to adulthood.

Self-assessed body size at age 8, at puberty, at age 20-25, and at age 35-40 and trajectories of body size of 4 662 breast cancer survivors from the prospective E3N cohort were studied in relation to risk of death from any cause, death from breast cancer and second invasive cancer event using multivariate Cox regression models.

Four trajectories of body size were identified (T1 "moderate increase", T2 "stable/low increase", T3 "increase at puberty", T4 "constantly high"). Compared with stable body size, an increase in body size during adult life was associated with an increased risk of death from any cause (HR T1 versus T2=1.27; 95% CI=1.01-1.60), and an increased risk of second invasive cancer event (HR T1 versus T2=1.25; 95% CI=1.06-1.47). Silhouettes at various ages were not associated with survival.

Our results suggest that the evolution of body size from childhood to adulthood has a long-term influence on breast cancer survival. Although these results need to be confirmed, this work sheds light on the need to combine lifelong approaches to current BMI to better identify breast cancer survivors who are at higher risk of recurrence or second primary cancer, or of death. This article is protected by copyright. All rights reserved.

http://ift.tt/2naSFCH