@article{3161024,
    title = "Anthropometric and Hormonal Risk Factors for Male Breast Cancer: Male
Breast Cancer Pooling Project Results",
    author = "Brinton, Louise A. and Cook, Michael B. and McCormack, Valerie and and Johnson, Kenneth C. and Olsson, Hakan and Casagrande, John T. and Cooke, and Rosie and Falk, Roni T. and Gapstur, Susan M. and Gaudet, Mia M. and and Gaziano, J. Michael and Gkiokas, Georgios and Guenel, Pascal and and Henderson, Brian E. and Hollenbeck, Albert and Hsing, Ann W. and and Kolonel, Laurence N. and Isaacs, Claudine and Lubin, Jay H. and Michels, and Karin B. and Negri, Eva and Parisi, Dominick and Petridou, Eleni Th. and and Pike, Malcolm C. and Riboli, Elio and Sesso, Howard D. and Snyder, Kirk and and Swerdlow, Anthony J. and Trichopoulos, Dimitrios and Ursin, Giske and and van den Brandt, Piet A. and Van Den Eeden, Stephen K. and and Weiderpass, Elisabete and Willett, Walter C. and Ewertz, Marianne and and Thomas, David B. and European Rare Canc Study Grp",
    journal = "JNCI Journal of the National Cancer Institute",
    year = "2014",
    volume = "106",
    number = "3",
    publisher = "OXFORD UNIV PRESS INC",
    issn = "0027-8874, 1460-2105",
    doi = "10.1093/jnci/djt465",
    abstract = "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."
}