%0 Journal Article %T Role of Obesity in the Risk of Breast Cancer: Lessons from Anthropometry %A Amina Amadou %A Pierre Hainaut %A Isabelle Romieu %J Journal of Oncology %D 2013 %I Hindawi Publishing Corporation %R 10.1155/2013/906495 %X An estimated 1.38 million new cases of breast cancer (BC) are diagnosed each year in women worldwide. Of these, the majority are categorized as invasive ductal cell carcinoma. Subgroups of BC are frequently distinguished into five ˇ°intrinsicˇ± subtypes, namely, luminal A, luminal B, normal-like, HER2-positive, and basal-like subtypes. Epidemiological evidence has shown that anthropometric factors are implicated in BC development. Overall consistent positive associations have been observed between high body mass index (BMI) and waist-to-hip ratio (WHR) and the risk of BC among postmenopausal women, while conflicting results persist for premenopausal BC, both for BMI and for other anthropometric parameters as well as across ethnic groups. Furthermore, some evidence suggests that body size, body shape, and weight gain during childhood or adolescence may play a role in the risk of BC. In this paper, we describe the evidence linking anthropometric indices at different ages and BC risk, in order to improve our understanding of the role of body fat distribution in the risk of BC, investigate differences in these associations according to menopausal status and ethnic groups, and discuss the potential biological mechanisms linking body size and BC risk. 1. Introduction Breast cancer (BC) is the most frequently diagnosed cancer in women worldwide, accounting for 23% (1.38 million) of the total new cancer cases in 2008 [1, 2]. The majority of invasive breast neoplasms are categorized as ˇ°invasive ductal cell carcinoma, not otherwise specifiedˇ± (ICD-O 8500/3) [3]. This entity has long been recognized to include tumors with heterogeneous molecular characteristics, characterized by distinct patterns of gene expression [4] and of genomic/genetic alterations [5]. Subgroups of BC are frequently distinguished into luminal A (estrogen/progesterone-positive), luminal B, HER2+, and so-called ˇ°triple negativeˇ± subtypes [6]. Among these subtypes, HER2+ and basal-like subtypes tend to be more common among premenopausal women, as well as in women of African ancestry. Luminal subtypes are more common in postmenopausal women and among Caucasians [7]. The incidence rates of BC show a heterogeneous distribution, while Western countries present the highest incidence rates, the lowest incidences are observed in low resource countries. BC ranks as the fifth cause of death from cancer overall (458,000 deaths), but is still the most frequent cause of cancer death in women in both developing (269,000 deaths) and developed regions (189,500 deaths) [1]. Incidence and mortality rates have %U http://www.hindawi.com/journals/jo/2013/906495/