Anthropometric and Hormonal Risk Factors for Male Breast Cancer: Male Breast Cancer Pooling Project Results

• Published in: JNCI : Journal of the National Cancer Institute Vol. 106; no. 3; p. djt465
• Main Authors: Brinton, L. A., Cook, M. B., McCormack, V., Johnson, K. C., Olsson, H., Casagrande, J. T., Cooke, R., Falk, R. T., Gapstur, S. M., Gaudet, M. M., Gaziano, J. M., Gkiokas, G., Guenel, P., Henderson, B. E., Hollenbeck, A., Hsing, A. W., Kolonel, L. N., Isaacs, C., Lubin, J. H., Michels, K. B., Negri, E., Parisi, D., Petridou, E. T., Pike, M. C., Riboli, E., Sesso, H. D., Snyder, K., Swerdlow, A. J., Trichopoulos, D., Ursin, G., van den Brandt, P. A., Van Den Eeden, S. K., Weiderpass, E., Willett, W. C., Ewertz, M., Thomas, D. B.
• Format: Journal Article
• Language: English
• Published: Cary, NC Oxford University Press 2014
• Subjects: Adult; Aged; Biological and medical sciences; Body Mass Index; Breast Neoplasms, Male - etiology; Breast Neoplasms, Male - genetics; Breast Neoplasms, Male - metabolism; Cancer and Oncology; Cancer och onkologi; Case-Control Studies; Clinical Medicine; Cohort Studies; Epididymitis - complications; Gonadal Steroid Hormones - metabolism; Gynecology. Andrology. Obstetrics; Gynecomastia - complications; Humans; Klinefelter Syndrome - complications; Klinisk medicin; Logistic Models; Male; Mammary gland diseases; Medical and Health Sciences; Medical sciences; Medicin och hälsovetenskap; Middle Aged; Multiple tumors. Solid tumors. Tumors in childhood (general aspects); Odds Ratio; Orchitis - complications; Overweight - complications; Reproduction; Risk Assessment; Risk Factors; Testis - injuries; Tumors; Mammary gland diseases; Breast disease; Cancerology; Anthropometry; Risk factor; Male; Breast cancer; Malignant tumor; Epidemiology; Cancer
• ISSN: 0027-8874; 1460-2105; 1460-2105
• DOI: 10.1093/jnci/djt465

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 case-control and 10 cohort investigations involving 2405 case patients (n = 1190 from case-control and n = 1215 from cohort studies) and 52013 control subjects, individual participant data were harmonized and pooled. Unconditional logistic regression generated study design-specific (case-control/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 case-control 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.