A gene that greatly increases a woman's risk of breast cancer also causes a particularly deadly form of prostate cancer, say Canadian researchers who studied 301 prostate cancer patients. On average, those with the defective BRCA2 gene lived an average of four years after diagnosis. The average survival time for prostate cancer patients is 12 years.

The University of Toronto study, published in the British Journal of Cancer, appears to confirm previous findings that BRCA2 is associated with highly dangerous prostate cancer, BBC News reported. An Icelandic study found that prostate cancer patients with the gene lived an average of 2.1 years.

The defective BRCA2 gene is found in about one in 500 men, and men with the gene can be five times more likely to develop prostate cancer than men in the general population.

"Although only a very small percentage of men with prostate cancer will carry a faulty BRCA2 gene, they're much more likely to die from the disease," Dr. Lesley Walker, of the charity Cancer Research UK, told BBC News. "It is important that more research is done in this area to ensure that this group is targeted effectively so cancer is picked up at an early stage and, more importantly, that they are given the most appropriate treatment."