Breast cancer is a malignant tumor that has developed from cells of the breast. Although the disease occurs primarily in women, it occasionally occurs in men too. Read on to get the facts.

Many people do not realize that men have breast tissue and that they can develop breast cancer. Until puberty, young boys and girls have a small amount of breast tissue consisting of a few ducts (tubular passages) located under the nipple and areola (area around the nipple). At puberty, a girl's ovaries produce female hormones, causing breast ducts to grow, lobules (milk glands) to form at the ends of ducts and the amount of stroma (fatty and connective tissue surrounding ducts and lobules) to increase. On the other hand, male hormones produced by the testicles prevent further growth of breast tissue. Men's breast tissue contains ducts but only a few, if any, lobules.

More On Breast Cancer

Like all cells of the body, a man's breast-duct cells can undergo cancerous changes. Because women have many more breast cells than men do, and perhaps because their breast cells are constantly exposed to the growth-promoting effects of female hormones, breast cancer is much more common in women.

The prognosis (outlook) for men with breast cancer was once thought to be worse than that for women, but this is not true. Stage for stage, the survival rates are equal. In other words, men and women with each stage of breast cancer have a similar outlook for survival. Although at one time breast cancers of men were more often diagnosed at more advanced stages, this may no longer be true.

For detailed statistics on men and breast cancer, click here.

Go to the American Cancer Society site to learn more about this issue.