TY - JOUR TI - Anthropometric and Hormonal Risk Factors for Male Breast Cancer: Male Breast Cancer Pooling Project Results AU - Brinton, Louise A. AU - Cook, Michael B. AU - McCormack, Valerie and AU - Johnson, Kenneth C. AU - Olsson, Hakan AU - Casagrande, John T. AU - Cooke, AU - Rosie AU - Falk, Roni T. AU - Gapstur, Susan M. AU - Gaudet, Mia M. and AU - Gaziano, J. Michael AU - Gkiokas, Georgios AU - Guenel, Pascal and AU - Henderson, Brian E. AU - Hollenbeck, Albert AU - Hsing, Ann W. and AU - Kolonel, Laurence N. AU - Isaacs, Claudine AU - Lubin, Jay H. AU - Michels, AU - Karin B. AU - Negri, Eva AU - Parisi, Dominick AU - Petridou, Eleni Th. and AU - Pike, Malcolm C. AU - Riboli, Elio AU - Sesso, Howard D. AU - Snyder, Kirk AU - and Swerdlow, Anthony J. AU - Trichopoulos, Dimitrios AU - Ursin, Giske AU - and van den Brandt, Piet A. AU - Van Den Eeden, Stephen K. and AU - Weiderpass, Elisabete AU - Willett, Walter C. AU - Ewertz, Marianne and AU - Thomas, David B. AU - European Rare Canc Study Grp JO - JNCI Journal of the National Cancer Institute PY - 2014 VL - 106 TODO - 3 SP - null PB - OXFORD UNIV PRESS INC SN - 0027-8874, 1460-2105 TODO - 10.1093/jnci/djt465 TODO - null TODO - The etiology of male breast cancer is poorly understood, partly because of its relative rarity. Although genetic factors are involved, less is known regarding the role of anthropometric and hormonally related risk factors. In the Male Breast Cancer Pooling Project, a consortium of 11 casecontrol and 10 cohort investigations involving 2405 case patients (n 1190 from casecontrol and n 1215 from cohort studies) and 52013 control subjects, individual participant data were harmonized and pooled. Unconditional logistic regression generated study designspecific (casecontrol/cohort) odds ratios (ORs) and 95% confidence intervals (CIs), with exposure estimates combined using fixed effects meta-analysis. All statistical tests were two-sided. Risk was statistically significantly associated with weight (highest/lowest tertile: OR 1.36; 95% CI 1.18 to 1.57), height (OR 1.18; 95% CI 1.01 to 1.38), and body mass index (BMI; OR 1.30; 95% CI 1.12 to 1.51), with evidence that recent rather than distant BMI was the strongest predictor. Klinefelter syndrome (OR 24.7; 95% CI 8.94 to 68.4) and gynecomastia (OR 9.78; 95% CI 7.52 to 12.7) were also statistically significantly associated with risk, relations that were independent of BMI. Diabetes also emerged as an independent risk factor (OR 1.19; 95% CI 1.04 to 1.37). There were also suggestive relations with cryptorchidism (OR 2.18; 95% CI 0.96 to 4.94) and orchitis (OR 1.43; 95% CI 1.02 to 1.99). Although age at onset of puberty and histories of infertility were unrelated to risk, never having had children was statistically significantly related (OR 1.29; 95% CI 1.01 to 1.66). Among individuals diagnosed at older ages, a history of fractures was statistically significantly related (OR 1.41; 95% CI 1.07 to 1.86). Consistent findings across casecontrol and cohort investigations, complemented by pooled analyses, indicated important roles for anthropometric and hormonal risk factors in the etiology of male breast cancer. Further investigation should focus on potential roles of endogenous hormones. ER -