Incidence and outcome of male breast cancer: an international population-based study.

PURPOSE Male breast cancer is a rare disease with an incidence rate less than 1% of that of female breast cancer. Given its low incidence, few studies have assessed risk and prognosis. METHODS This population-based study, including 459,846 women and 2,665 men diagnosed with breast cancer in Denmark, Finland, Geneva, Norway, Singapore, and Sweden over the last 40 years, compares trends in incidence, relative survival, and relative excess mortality between the sexes. RESULTS World standardized incidence rates of breast cancer were 66.7 per 10(5) person-years in women and 0.40 per 10(5) person-years in men. Women were diagnosed at a younger median age (61.7 years) than men (69.6 years). Male patients had a poorer 5-year relative survival ratio than women (0.72 [95% CI, 0.70 to 0.75] v 0.78 [95% CI, 0.78 to 0.78], respectively), corresponding to a relative excess risk (RER) of 1.27 (95% CI, 1.13 to 1.42). However, after adjustment for age and year of diagnosis, stage, and treatment, male patients had a significantly better relative survival from breast cancer than female patients (RER, 0.78; 95% CI, 0.62 to 0.97). CONCLUSION Male patients with breast cancer have later onset of disease and more advanced disease than female patients. Male patients with breast cancer have lower risk of death from breast cancer than comparable female patients.