LEBANON — Screening colon cancer patients for the hereditary Lynch syndrome has become a common practice at many academic cancer centers across the country, but perhaps it is time to start screening uterine cancer patients as well, says a Norris Cotton Cancer Center review to be published early next year.
Next to colorectal cancer, endometrial cancer is the most common form of cancer in women with Lynch syndrome, Norris Cotton Cancer Center researchers said in a press release Wednesday.
A review by the researchers of current scientific evidence that warrants screening all endometrial cancers for Lynch syndrome is to be published in the January 2014 issue of the journal Clinical Chemistry.
Any Dartmouth-Hitchcock Medical Center patient diagnosed with colon cancer is screened for Lynch syndrome via specialized tumor testing.
"The reason is that there is a push to identify people with Lynch syndrome is twofold," Eleanor Riggs, a genetic counselor at the Norris Cotton Cancer Center's Familial Cancer Program, said Wednesday. "If someone with colon cancer has Lynch syndrome they are at risk for other cancers. … The second reason is for the family, because if you find out if someone has Lynch syndrome then all their first-degree relatives have a 50 percent chance of also having the condition."
Lynch syndrome is the most common form of hereditary colorectal cancer and is caused by germline mutations in DNA mismatch repair genes, according to the Journal of the American Medical Association.
A colon cancer patient's tumor is first tested for the presence or absence of the proteins that form the four possible genes that cause Lynch syndrome, Riggs said. If found the patient then meets with a genetic counselor like Riggs for further testing and possibly family testing.
Those with Lynch syndrome tend to be afflicted with earlier onset forms of cancer. A person in their 20s found to have Lynch syndrome may be advised to have colonoscopies every one to two years as opposed to what people with the general population risk are told, which is to receive colonoscopies at the age of 50 and then at 10-year intervals, Riggs said.
"Lynch syndrome is one of the possibilities or one of the causes of the predisposition to colon cancer," Riggs said. "There are a couple of them, but Lynch syndrome is one of them."
Lynch syndrome also points to a predisposition to other cancers such as uterine, ovarian, stomach, pancreatic, urinary tract, kidney and biliary tract, Riggs said.
Riggs said her department has been testing all colon cancer patients at Dartmouth-Hitchcock for the past year for Lynch syndrome and all colon cancer patients for Lynch syndrome who were younger than 60 since about 2008.
It's time to start contemplating screening uterine cancer patients for Lynch syndrome, she said.
While the general population risk for uterine cancer is 1.5 to 2 percent, those with Lynch syndrome carry a lifetime risk of 25 to 60 percent.
"It's a big jump up," Riggs said.
If the patient is found to have Lynch syndrome, their family members can also be tested for the syndrome and take measures to ultimately reduce their risk for getting cancer, she said.