Vancouver, British Columbia—Mayo Clinic researchers are calling for all young patients with colorectal cancer (CRC) to undergo preoperative testing for Lynch syndrome as the results can significantly alter surgical management.

“The benefit of this testing to the patient and their family is huge,” said Rajesh Pendlimari, MBBS, a research fellow at Mayo Clinic in Rochester, Minn., and a study investigator.

“If they have Lynch syndrome and will, therefore, be more prone to getting cancer, they can get screened more regularly. The knowledge gleaned can change the course of surgical treatment.”

At the 2011 annual meeting of the American Society of Colon and Rectal Surgeons, the Mayo team presented two studies examining the benefit of pre- and postoperative microsatellite instability (MSI) testing for Lynch syndrome.

In the first study, 210 of 258 newly diagnosed patients younger than age 50 years who underwent colorectal surgery at Mayo Clinic had MSI testing between 2003 and 2008. Of these, 82 underwent testing postoperatively, according to the hospital’s protocol requiring pathologists to complete MSI testing on operative specimens for all young patients who did not have the tests done prior to surgery. Overall, 13% of patients were found to have high levels of MSI and 33% of these would have been missed without the testing protocol.

The second, complementary paper retrospectively compared the surgical management of 210 patients who were tested pre- and postoperatively for MSI (n=103, n=107, respectively).

Results showed that the MSI test results significantly influenced surgical recommendations for total colectomy. Of patients with positive preoperative MSI tests (MSI-H), 94% underwent total colectomy, compared with 8% of patients whose status was not known until after surgery (P<0.0001). Moreover, there appears to be an increased rate of hysterectomy among women with MSI-H. Eight of 10 MSI-H women had a hysterectomy. There was only one female patient who was tested postoperatively and she did not have a hysterectomy.

“Probably the most significant result of this research is that it has stimulated our multidisciplinary team of geneticists, pathologists, gastroenterologists and surgeons to develop new clinical pathways that will direct patients at risk to providers experienced with management of Lynch syndrome,” said Eric Dozois, MD, professor of surgery at Mayo Clinic and lead researcher on the project.

Other gastroenterologists and surgeons applauded the paper, saying that preoperative testing for Lynch syndrome is easy to do and can dramatically affect surgical treatment.