Men who develop breast cancer are more than twice as likely as other men to have female relatives with breast cancer. And, if there is a family history of breast cancer among first degree relatives (mother, sisters or daughters) men are about four times more likely to develop breast cancer than men in families where no close relatives are affected. These facts have suggested that there might be a genetic link for some men who develop breast cancer.

Some breast cancers in women are linked to changes in the genes. The two most important of these are the BRCA1 and BRCA2 genes. Abnormal changes (mutations) in one or other of these two genes greatly increase the risk of a woman developing breast cancer before the age of 70.

In men, mutations of the BRCA1 gene do not seem to increase the chances of getting a breast cancer. But BRCA2 mutations definitely are linked to an increase risk of breast cancer developing. More than half the men who have breast cancer and a close female relative with breast cancer are likely to have BRCA2 mutations.

So a man who has breast cancer and a strong family history of breast cancer among his close female relatives may have a BRCA2 mutation.

It is thought that about 1 in 5 breast cancers in men are related to abnormal changes in the BRCA2 gene.

Breast cancers in men that are linked to BRCA2 mutations don't seem to behave differently from other breast cancers in men, although they tend to affect men at a younger age than average. (The average for the discovery of breast cancer in men is in the late sixties.)