1. ¹Equipe Inserm 'Nutrition, Hormones et Cancer', Institut Gustave Roussy, 39 rue Camille Desmoulins, 94805 Villejuif Cedex, France
2. ²International Agency for Cancer Research, Lyon, France

Correspondence: Dr F Clavel-Chapelon, E-mail: clavel@igr.fr

Received 1 January 2005; Revised 13 April 2005; Accepted 13 April 2005; Published online 24 May 2005.

Abstract

We analysed the relation between adult breast cancer risk and adiposity in ages 8–25, and among 90 509 women included in the E3N cohort study, and investigated the potential modification effect of certain factors. Participants completed a questionnaire that included a set of eight silhouettes corresponding to body shape at different ages. During the follow-up (mean=11.4 years), 3491 breast cancer cases were identified. Negative trends in risk of breast cancer with increasing body silhouettes at age 8 and at menarche were observed, irrespective of menopausal status, with relative risks of 0.73 (0.53–0.99) and 0.82 (0.66–1.02) for women who reported a silhouette equal or greater than the fifth silhouette at age 8 and at menarche, respectively. We observed no clear effect modification by age at menarche, delay between age at menarche, regular cycling, regularity of cycles in adult life or body mass index at baseline.