Anthropometric and Hormonal Factors Increase Risk for Male Breast Cancer
In a study reported in the Journal of the National Cancer Institute, Brinton et al assessed the role of anthropometric, medical history, and hormone-related factors in male breast cancer in the Male Breast Cancer Pooling Project. Factors found to be associated with risk included height, weight, body mass index (BMI), Klinefelter syndrome, gynecomastia, diabetes, and fractures.
Study Details
The Male Breast Cancer Pooling Project is a consortium of 11 case-control (1,190 case patients, 4,531 controls) and 10 cohort (1,215 case patients, 47,482 controls) investigations involving 2,405 case patients and 52,013 control subjects. Individual participant data were harmonized and pooled, and unconditional logistic regression analysis generated study design-specific (case-control/cohort) odds ratios (ORs), with exposure estimates combined using fixed effects meta-analysis.
Risk Factors
Among anthropometric variables, the meta-analysis showed that independent risk factors for breast cancer were highest vs lowest tertiles of body weight (OR = 1.36, P < .001), height (OR = 1.18, P = .03), and BMI (OR = 1.30; 95% CI = 1.12–1.51), with evidence indicating that recent BMI is a stronger predictor than less-recent BMI.
Among medical diagnoses, independent risk factors were Klinefelter syndrome (resulting from additional X genetic material in males; OR = 24.7, P < .001), gynecomastia (OR = 9.78, P < .001), diabetes (OR = 1.19, P = .01), and orchitis (OR = 1.43, P = .04).
Among reproductive parameters, age at onset of puberty and history of infertility were not related to risk, but never having had children was an independent predictor (OR = 1.29, P = .04).
Among individuals diagnosed with breast cancer at age ≥ 66 years, history of fracture was associated with increased risk (OR = 1.41, P = .02).
The investigators concluded, “In this pooled analysis, we identified statistically significant associations of male breast cancer with a number of anthropometric and hormonally related risk factors, including BMI and various medical and reproductive parameters. Many of these risk factors support the need for exploring the role of endogenous hormones, which will be assessed in future analyses using samples from our cohort investigations.”
Louise A. Brinton, PhD, of the National Cancer Institute, is the corresponding author for the Journal of the National Cancer Institute article.
This study was funded in part by the National Institutes of Health.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
