Demystifying Colorectal Hereditary Syndromes

Medical and surgical strategies for gastrointestinal cancer surveillance were discussed by a researcher from Puerto Rico at a presentation given this week during a joint conference of the American Gastroenterological Association and the American Society for Gastrointestinal Endoscopy in Coronado, California.

About one in 25 people in the United States will develop colorectal cancer, said Marcia Cruz-Correa, MD, an associate professor of medicine and biochemistry at the University of Puerto Rico at San Juan. The risk increases to about 15 to 20 percent when a family member has the disease, she said.

People with hereditary colorectal syndromes such as Lynch syndrome, adenomatous polyposis, and hamartomatous polyposis have a much higher likelihood of developing colorectal cancer.

Cancer in people with Lynch syndrome usually develops before the age of 50, with the tumors on the right side of the colon about 60 percent of the time. “If someone has Lynch syndrome by age 50, 25 percent of them will already have colorectal cancer, compared to less than 5 percent in the US population,” said Cruz-Correa.

Lynch syndrome also increases risks for several other noncolorectal cancers, including cancer of the small bowel and the brain, according to Cruz-Correa, who noted that the syndromes in her discussion are not just colorectal syndromes but cancer syndromes. “Patients that present to us for evaluation for colorectal cancer might have a high risk of having some other tumors,” she said.

In fact some women with these syndromes may be diagnosed first with endometrial cancer before the colorectal develops or is discovered. “So we need to be very cognizant about this these are cancer syndromes,” said Cruz-Correa.

With colorectal cancer surveillance, testing high-risk patients begins with conducting a colonoscopy between the ages of 20 to 25 and repeating the procedure every year or two. When the patient turns 40 it should be done every year. “We know that this reduces colorectal cancer risk and mortality,” Cruz-Correa said.

Since colorectal hereditary syndromes are also cancer syndromes, surveillance is also recommended for other cancers such as endometrial, gastric, and small bowel cancer, Cruz-Correa said.

Marcia Cruz-Correa has held speaking and teaching engagements at Myriad Genetic Laboratories.