Men from families where the women have high rates of breast cancer could face a heightened risk of prostate cancer, Australian researchers said Monday.
A mutated gene seen as a factor in breast cancer can also expose men to a four times higher risk of prostate cancer, the scientists said, describing confirmation of the link as a world first.
The research was funded by Australia's National Breast Cancer Foundation and carried out by researchers at kConFab, an Australian and New Zealand consortium for research into familial breast cancer.
The consortium has been investigating families with multiple cases of breast and ovarian cancer for 10 years and noticed that prostate cancer was also common in some of the families, said kConFab national manager Heather Thorne.
Those families carried a mutation in the BRCA2 gene, which is passed from one generation to the next, and "this led us to explore whether these prostate cancers were caused by the genetic fault running in the family," she said.
"We discovered that a man with a genetic fault in BRCA2 has almost four times the risk of developing prostate cancer than men in the general population.
"The BRCA2-prostate cancers that arise in these men also tend to be more aggressive".
It was hoped the discovery would lead men to assess their personal risk in the same way women already do with breast and ovarian cancer, Thorne said in a statement.
"If a man comes from a family with multiple cases of breast or ovarian cancer, or knows there is a BRCA2 gene mutation running in their family, they may be at increased risk of developing prostate cancer.
"These men can go to a Family Cancer Clinic and discuss genetic testing, and be given appropriate advice if they are found to be at increased risk."
Breast cancer survivors who find they have a mutation in the BRCA2 gene will also now know that their brothers or sons could be at increased risk of prostate cancer, she said.
The results of the research were published this week in the US journal Clinical Cancer Research and trials were now being undertaken to try to find early detection biomarkers for men who carry the faulty genes, Thorne said.
Prostate cancer is the commonest cancer afflicting men in developed countries.