Family of Those With Benign Polyps May Be at Risk

Close relatives of patients with benign polyps in their colons or rectums run an increased risk of developing cancer in those regions, according to a study published recently in the New England Journal of Medicine.

As a result of their findings, the investigators from nine medical centers across the United States and one in Great Britain suggested that people younger than 60 who are parents or siblings of patients with benign polyps undergo routine screening.

Because it takes as long as 10 years for these benign polyps to develop, the investigators, headed by Dr. Sidney J. Winawer of the National Polyp Study Headquarters at Memorial Sloan-Kettering Cancer Center in New York, said screenings should be done at five-year intervals.

With the cost of medical treatment constantly being evaluated, the researchers said they are unsure whether such screening would be cost-effective even though it could help reduce the incidence of colon and rectal cancers.

The study looked at 1,031 patients with newly diagnosed benign polyps who were part of the National Polyp Study at seven clinical centers. The investigators then looked at the rates of colon and rectal cancer among parents and siblings and compared them with the rate among spouses serving as a control group.

Earlier studies had shown that patients with benign polyps run an increased risk of developing colon or rectal cancer if the polyps are not removed.

This study showed that cancer risks were significantly higher among parents and siblings of patients in whom the benign polyps were found before they turned 50 and for siblings of patients between 50 and 60 when the benign polyps were found.

The investigators said it was unclear why close relatives of patients with benign colon or rectal polyps ran an increased risk of developing cancer. They suggested that it could be due to a common genetic mutation, but said they were unable to find any.