Colon cancer patients with a family history of the malignancy are more likely to survive, according to a study that raises the possibility that the same genes that increase risk may also provide a defense against the disease.
The study in the Journal of the American Medical Association found people whose parents or siblings had colorectal cancer were 28 percent less likely to die from their tumors or suffer a relapse. Having more close relatives with cancer increased a person’s survival chances, researchers said. People with two affected relatives had a 51 percent lower risk of death or recurrence than those with one.
While the research didn’t identify a specific genetic connection, it did rule out lifestyle factors or early detection as reasons for improved survival. About 16 percent to 20 percent of patients with colon cancer have a close relative with colon cancer, researchers said in the study. A genetic connection to surviving the disease as well may help lead doctors to new ways to test for and treat the disease.
“If we can understand the biological mechanism for why patients are doing differently and we’re able to develop a treatment that targets that mechanism, then people may have a better outcome,” said Jennifer Chan, a doctor at Boston’s Dana-Farber Cancer Institute and lead author of the paper. “But a lot of testing needs to be done before we’re there.”
Almost 150,000 people in the U.S. will be diagnosed with colorectal cancer in 2008, according to the American Cancer Society.
