Eligibility for Genetic Testing in Lynch Syndrome Expands With New NCCN Guidelines

More patients with Lynch syndrome will be eligible for genetic testing with availability of a new, more sensitive assay from Myriad Genetics and support for wider use of the test through guidelines issued by the National Comprehensive Cancer Network.

New guidelines from the National Comprehensive Cancer Network (NCCN) expand screening tests for patients with Lynch syndrome. This hereditary syndrome requires genetic testing for the genetic tendency for colon cancer. The new guidelines are designed to better protect patients with mutated genes that increase the risk of colon cancer and endometrial cancer in patients with Lynch syndrome.

A patient with a mutation of 1 of the 5 genes associated with Lynch syndrome—including genes known by the names MLH1, MSH2, MSH6, PMS2, and EPCAM—increases the risk of developing colorectal cancer by 82% over a lifetime. In addition, women with a single mutation of any of these genes are 71% more likely to develop endometrial cancer than an unaffected individual. Not only does Lynch syndrome increase the risk of colorectal and endometrial cancer, but the diagnosis tends to occur earlier in life at an average age of 45 years, versus 63 years for a patient without Lynch syndrome.

Under the new guidelines testing is recommended for at-risk patients, which should change insurance reimbursement policies for these patients. Patients with a 5% or greater risk of Lynch syndrome should receive testing for all 5 genes—not sequentially, as was done in the past, but through panel testing, in which testing for the presence or absence of each gene occurs simultaneously. In addition, patients who have already developed endometrial or colon cancer can receive gene sequencing testing immediately—not after a complicated tissue screening step, as was done in the past.

Changes to the guidelines were necessitated by a new, more sensitive test for the mutations associated with Lynch syndrome developed by Myriad Genetic Laboratories.

"Myriad will continue to work with professional organizations to identify appropriate patients, especially as we launch our next generation test, Myriad myRisk Hereditary Cancer, which has been shown to detect over 60 percent more deleterious mutations than standard of care in patients at risk of hereditary colon cancer," said Myriad president Mark Capone in a press release.