(Ivanhoe Newswire) -- Screening every new colon cancer patient for a particular familial disorder extends lives at a reasonable cost, Stanford University School of Medicine researchers said. The team hopes the results will encourage more medical centers to adopt widespread screening policies.

Approximately 3 to 5 percent of colorectal tumors are caused by a heritable condition called Lynch syndrome, which greatly increases the odds of colon and other cancers in a person's lifetime. Siblings and children of someone with Lynch syndrome each have a 50 percent chance of carrying the mutation, so the first diagnosis in a family reveals the risk for many relatives. But early detection can save lives.

"This is a situation where, if you find out genetic information, you can improve your outcome," Uri Ladabaum, MD, associate professor of gastroenterology and hepatology, and lead author of the study, was quoted as saying. Lynch syndrome patients can take defensive steps (such as yearly colonoscopies) that can either prevent cancer or alert them to get cancer treatment early, when it has the best chance of working.

"We were interested in whether it would be cost-effective to test a lot of colon tumors to find the few that are due to Lynch syndrome and, if so, what would be the most cost-effective strategy," said Ladabaum. He and his colleagues used computer simulations to compare the years of lives gained and the money spent if all new cases of colorectal cancer were tested for Lynch syndrome. They found that such screening programs can reduce cancer deaths at a price within the typical range of U.S. health-care costs. The study will be published in the July 19 issue of Annals of Internal Medicine.

Prior to the availability of genetic testing, Lynch syndrome was identified by sharp-eyed genetic counselors and physicians who noticed the high frequency of cancers in certain families. But this method isn't foolproof, especially if a patient doesn't know his or her family history. "We think there are other families out there that have a predisposition for cancers," co-author James Ford, MD, associate professor of oncology, of genetics and of pediatrics, was quoted as saying. "The initial small investment of doing the screen is ultimately going to pay off in terms of costs to society as well as in saving lives."

An average person's lifetime risk of developing colon cancer is around 5 percent. For a person with Lynch syndrome that risk grows to 70 percent or more. Lynch syndrome also raises the risk of other cancers, including uterine and ovarian cancer. Female patients with the disorder who get regular tumor checks and who choose to have preventative hysterectomies would benefit most from widespread screening of colon tumors, according to the study.

The most cost-effective method involved checking whether tumors were missing any molecular quality inspectors, followed by DNA sequencing of the suspected gene. But no matter which testing methods were used, it was most important to test multiple family members after the initial diagnosis. Pathologists use several tests to identify the specific mutation in the first family member, but that only needs to be done once. Subsequent diagnoses in relatives are much simpler. The researchers found that three or four family members needed to be tested and then follow recommended preventive measures for the process to have a reasonable price tag. "All these interventions are more likely to be cost-effective if you can spread the benefit across more relatives," said Ladabaum.

The study suggests that more medical centers could adopt tumor-screening policies like Stanford's. "A systematic approach to identify families with Lynch syndrome makes sense clinically, because it can save lives, and economically, because its costs are comparable to other things we choose to spend our health-care dollars on," said Ladabaum. "We advocate establishing similar tumor-screening systems on a national level."

SOURCE: Stanford University Medical Center press release