October 1, 2008

Gene Variation Linked To Colon Cancer

Researchers have discovered a genetic link to a hormone secreted by the body's fat cells that may lower the risk of colon cancer.

About half of the study's participants had the gene variation, which scientists believe controls the amount of the hormone adiponectin fat cells secrete.

Reporting in the Journal of the American Medical Association on Tuesday, researchers said people with more of the hormone in their blood are known to have a lower risk of colon cancer, but the body's mechanism for controlling adiponectin secretion by cells is unclear.

Obese people, who have a higher risk of cancer, tend to have less of the hormone. People with more adiponectin have less risk of heart disease and diabetes.

Overall, scientists analyzed data from two groups of 1,500 people.

In one group, New Yorkers of Ashkenazi Jewish ancestry who had the gene were 28 percent less likely to have been diagnosed with colon cancer. The disease is more common in Ashkenazi Jews -- who originated in Europe -- than the general population.

The other group, from Chicago, was diverse ethnically and those with the gene had a 52 percent lower risk.

"Is this the (genetic) snip that is the cause of the disease? Most likely not. It just gives us a region on the gene where we think the association to colorectal cancer risk stems from," said Dr. Boris Pasche of the University of Alabama at Birmingham. Pasche led the research, done primarily while he was at Northwestern University in Chicago.

Colon cancer will be diagnosed in 149,000 Americans this year and will kill 50,000, according to the American Cancer Society. Globally, about 1.2 million cases of colorectal cancer are diagnosed annually and the disease kills about 630,000 people.

Apart from genetics, other contributing factors include high fat diets with low fiber, a sedentary lifestyle and heavy drinking and smoking.

Tracing the genetic source of diseases such as cancer is in its infancy, but holds promise. If diagnosed early, colon cancer is highly treatable, Pasche said.


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