Breast cancer, male: Breast cancer in a man. Male breast cancer is much less common than breast cancer in women. Fewer than 1% of persons with breast cancer are male. However, breast cancer is no less dangerous in males than in females. After the diagnosis of breast cancer is made, the mortality rates are virtually the same for men and for women.

Male breast cancer tends to occur after age 50. Men taking estrogen or naturally producing higher levels of the hormone are at increased risk, as are men with Klinefelter syndrome, which results in low testicular function. As with women, men with relatives who carry the breast cancer gene are at elevated risk. And as with breast cancer in women, black men are more likely than white men to die of the disease.

About 175,000 women will be diagnosed with breast cancer annually in the US and 40,000 of these women will die of the disease. By comparison, breast cancer will be diagnosed in about 1,500 men this year and 400 of these men will die of their disease.