“Our study supports that MSI-high is predictive of LS across tumor types...and also supports that the spectrum of cancers associated with Lynch Syndrome seems to be much broader that previously thought, she said, concluding that “MSI-high tumor signature, regardless of cancer subtype and irrespective of the family cancer history, should prompt germline genetic assessment for the evaluation of Lynch [Syndrome].
“This will result in an increased ability to recognize Lynch Syndrome not only in cancer patients, but also in at-risk family members who will benefit from genetic testing for Lynch [Syndrome] and subsequent enhanced cancer surveillance and risk reduction measures.”
In emphasizing the practice-changing nature of these findings, Dr. Westin, a gynecologic oncologist at MD Anderson Cancer Center, Houston, said that with the rise of precision medicine, increasing numbers of patients are undergoing testing for microsatellite instability, mainly to determine if their tumor can be affected by an-approved therapy.
“What we’ve learned is that MSI not only has therapeutic implications, it also has cancer prevention implications,” she said. “We’ve only been testing the tip of the iceberg of patients who are affected by Lynch Syndrome, and what we now know is that under the surface there is a larger number of patients with specific cancer types that should be tested for Lynch Syndrome.”