Colon Cancer Risk: It's Often All in the Family
Forty-one-year-old Amenia Lauth has a family history of colon cancer. Her grandfather and uncle, both of whom developed colon cancer at a young age, succumbed to the disease, and several other relatives had precancerous polyps in their colon.
After a colonoscopy revealed that Lauth had thousands of polyps lining her colon, doctors at the University of Michigan Health System recognized that she had familial adenomatous polyposis, a condition with a high risk of colon cancer. Because of her family history, Lauth wondered if her children, too, were genetically predisposed to colon cancer. Fortunately, genetic screening and counseling found that none of her three children were carriers of the familial adenomatous polyposis gene that caused her polyps.
"I felt a great deal of relief after they were screened because it meant that they wouldn't have to go through what I had gone through," says Lauth, who had her colon removed following her diagnosis to prevent colon cancer from occurring.
Since about 10 percent of all colon cancers have a genetic component to them, experts at the University of Michigan Comprehensive Cancer Center recommend that people with a strong family history of colon cancer get genetic counseling and early screening, like Lauth and her children, to know their risks.
"Colon cancer is one of the most common cancers in the United States, and the good news is that it's largely preventable with early screening," says Stephen B. Gruber, M.D., Ph.D., director of the cancer genetics clinics at the U-M Cancer Center, and associate professor of internal medicine at the U-M Medical School.
The American Cancer Society estimates that some 150,000 new cases of colon cancer will be diagnosed in 2007, and more than 50,000 deaths from colorectal cancer will occur.
Although most cancers are not "inherited," some families are particularly susceptible to cancer and may benefit from early detection or other risk reduction strategies. Genetic counseling and screening can help to identify two common conditions associated with familial colon cancer risk: familial adenomatous polyposis, which caused colon cancer in Lauth's family, or Lynch Syndrome, which usually causes cancer to develop either in the colon or the uterus.
"The best way to recognize Lynch Syndrome is to look at the patient's family history to see if three or more family member have been diagnosed with colon cancer, and if any have been diagnosed before the age of 50," notes Gruber. "Young onset colon cancer is one of the clues to inherited susceptibility for cancer."
People concerned about a family history of cancer, or those who have been diagnosed with colon cancer before age 50, should talk to their doctor about the possible benefits of genetic counseling. In fact, Gruber encourages any patient with cancer who has two or more family members with colon cancer to consider genetic counseling.