By now, many women know that having a family history of breast or ovarian cancer puts them at higher risk for developing these cancers themselves. But the men in such families may not realize they also could be at risk.

A history of breast and ovarian cancer may mark a family that carries the BRCA1 or BRCA2 gene mutation. These gene mutations are responsible for about 5%-10% of all breast cancers in women, as well as many ovarian cancers. Now, an article in the Journal of Clinical Oncology (Vol. 22, No. 4: 735-742) describes what is known about the cancer risks in men who carry these mutations.

Men who have a mutation of their BRCA gene have a higher-than-normal chance of developing several types of cancer, according to the researchers from Cedars-Sinai Medical Center in Los Angeles and Sunnybrook & Women's College Health Sciences Center in Toronto.

One of these is breast cancer. Although breast cancer is rare in men, those men with a BRCA2 mutation carry a risk 80 times that of other men. Their lifetime chance of developing the disease is 1 in 14. Still, this will only affect a small number of men, because breast cancer accounts for only 1% of cancers in men. About 1,400 men are diagnosed with this disease in the United States each year, according to American Cancer Society estimates. The researchers say about 15% of male breast cancers are caused by BRCA2 mutations.

The danger is much greater with prostate cancer, the most common cancer seen in men. More than 230,000 men will be diagnosed with this cancer in 2004. But the risk is even higher in men with one of these gene mutations, the review points out. The average man's chance of being diagnosed with prostate cancer during his lifetime is 1 in 6. But men with the BRCA2 mutation can have a risk as high as 1 in 3, and many of these cancers will develop in men under age 65, which is considered young for prostate cancer.

Melanoma is another cancer affected by BRCA gene mutations, the article says. This cancer, which already is more common in men than women, occurs twice as often in male BRCA carriers as in other men. Other cancers that are found more often in men with BRCA mutations include pancreatic and stomach cancers. All these cancers tend to develop at a younger age than expected.

Women who have a strong family history of breast or ovarian cancers often undergo genetic testing to see if they have either of these BRCA gene mutations. The researchers point out, though, that far fewer men with strong family histories of breast cancer are pursuing genetic testing.

"Misinformation about the cancer risks to men" may be part of the problem, they say.

The criteria for deciding which men need genetic testing should be similar to the criteria used for women, the researchers note.

Men from families with a history of breast and ovarian cancer should consider testing for the gene mutation, they say, particularly if any of the breast cancers occurred before age 50. Men with breast cancer themselves also are eligible. Men who have prostate cancer and a family history of breast cancer should also think about testing.

Men who know they carry a BRCA gene mutation can help protect themselves by being screened regularly for some of the cancers associated with the mutation. The researchers recommend annual prostate cancer screening with a PSA test, for instance, and annual skin examinations for melanoma. Although mammography is not recommended for most men, even if they carry a BRCA mutation, the researchers say men do need to seek medical advice about any changes in their breasts.