• 9/4/2005
  • Steven Reinberg
  • DrKoop.com

BRCA2 mutations up risks for other malignancies, study finds.

A mutation in the BRCA2 gene that increases the risk of breast and ovarian cancer in women may also increase the odds of pancreatic, prostate, bone and throat cancer in men, new research suggests.

Compared with the general population, those with the BRCA2 mutation were almost seven times more likely to have pharyngeal cancer and eight times as likely to have pancreatic cancer, Dutch researchers report. In addition, the investigators found that men with the mutation were more than twice as likely to have prostate cancer.

The report appears in the September issue of the Journal of Medical Genetics.

In the study, Dutch researchers led by Flora E. van Leeuwen, the head of the department of epidemiology at the Netherlands Cancer Institute, examined 139 families with 66 different mutations of the BRCA2 gene between them. The families were all part of a national register of families with a strong history of breast and/or ovarian cancers.

Of the 441 people tested for BRCA2, 69 percent had the mutation, the researchers reported. Overall, among 303 carriers of the mutation, there were 158 cases of cancer compared with 18 cases among 138 who did not carry the mutation.

Among those with the mutations, van Leeuwen’s team found that the cases of prostate, pancreatic, pharyngeal and bone cancers were substantially higher than is expected in the general population.

Individuals with the mutation were 15 times more likely to have bone cancer, although this could have been the result of spread from another primary cancer, van Leeuwen’s group noted.

According to the report, most of these increased risks were significant for men only, and were strongest for people under 65.

Since 11 of the 24 men with prostate cancer had died, van Leeuwen’s team suggests doctors consider early, radical treatment for men carrying the mutated gene.

“The observed risks for prostate cancer may warrant consideration of male carriers as candidates for inclusion in high-risk prostate screening studies,” the researchers wrote. “However, screening for prostate cancer is controversial.”

“Nevertheless, early radical treatment instead of watchful waiting, notably among patients with a life expectancy exceeding 15 years, might give survival benefit,” they said. “For all these reasons, surveillance of healthy men from BRCA2 families with an increased risk for developing prostate cancer should only be initiated in a research setting.”

One expert thinks these results need further proof before they could have an impact on treatment.

“I think the study tells us something we knew, but you need a clinical study before you can use this,” said Deborah Saslow, director of breast and gynecologic cancer at the American Cancer Society.

“We now have to see if it makes clinical sense to do anything with this information,” Saslow said. “This study is a statistical study; there needs to be a clinical trial to determine the next step. So it doesn’t really have any value to a doctor in terms of changing clinical practice right now.”