Men who have breast cancer have a significantly increased risk for a second cancer, malignant melanoma and stomach cancer, according to the largest study ever done on the subject. "We looked at the risk not only of a second breast cancer but also of other cancers. We found the risk of other cancers increased as well," said lead researcher Hoda Anton-Culver, director of epidemiology at the University of California at Irvine.
Breast cancer remains rare among men. About 1,400 new cases are reported in the US each year, according to the American Cancer Society.
Because of the relatively small incidence of male breast cancer, not one study until now has looked at large numbers, Anton-Oulver said. However, our study looks at a very large number of men," she said, "so there can be validity to large numbers of a rare cancer like this one."
The researchers analyzed data on 1,926 men with breast cancer. Of these, 221, or 11.5%, developed a second cancer at least two months after their breast cancer diagnosis.
One significant second cancer was malignant melanoma, with an incidence that was 50% higher than normal, as well as an elevated risk of stomach cancer, according to Anton-Culver.
There are several possible explanations for the increased risk, she said. It might be due to the side effects of treatment of the primary breast cancer, for example. But the most probable cause is genetics, she said, with the men being at "higher risk of developing cancer in general."
And studies by the group have shown a high incidence of a breast cancer-related gene, BRCA2, in the men, Anton-Culver said.
"We definitely do see an association between breast cancer in men and an increased risk of being a carrier of a cancer-related gene," AntonCulver said. That relationship indicates that a screening program looking at close relatives of men with breast cancer could help with the early detection of malignancies, she said.
Risk Factors for Men
Although breast cancer is approximately 100 times more common in women than in men, it will be diagnosed in an estimated 2,030 American men this year. Among men, those between the ages of 60 to 70 are at greatest risk.
Breast cancer risk factors for men include a family history of breast cancer in women or men), obesity, physical inactivity, radiation exposure, heavy alcohol consumption and estrogen treatment. Men who notice a lump or swelling skin dimpling, a nipple that turns inward...redness or scaling of the nipple or breast skin...or nipple discharge should see a doctor as soon as possible.