Adherence Poor for Lynch Syndrome Testing

There is poor adherence to recommended genetic testing and colonoscopy screening among patients at high-risk for Lynch syndrome, according to a study published online Feb. 9 in the American Journal of Gastroenterology. Furthermore, only a small percentage of their endoscopists provide these high-risk patients with appropriate screening recommendations, highlighting the need for improved educational interventions targeted to both providers and patients, the authors say.

While Lynch syndrome only accounts for two to four percent of all colorectal cancers (CRCs), those with the autosomal dominant mutation have up to an 80 percent lifetime risk of developing CRC, experts say. Professional guidelines recommend offering genetic counseling to all high-risk individuals and have found that aggressive screening reduces CRC incidence and mortality. But, the researchers say that individuals at risk for Lynch syndrome are “grossly under-recognized, resulting in missed opportunities to capture high-risk patients and their family members for appropriate genetic counseling and colonoscopic screening.”

At-risk participants in the Family Health Promotion Project (n=165) were surveyed at baseline and 24 months later to assess their knowledge of risk-appropriate guidelines for genetic counseling and colonoscopy screening. Participants were recruited from both high-risk cancer clinics and population-based registries of unaffected first-degree relatives of CRC patients. Follow-up recommendations made by their endoscopists were also assessed.

The survey revealed that the majority (98 percent) agreed that genetics and family history are important predictors of CRC. Yet, under two-thirds (63 percent) had heard of genetic testing for CRC, only 31 percent reported being advised to undergo genetic counseling by their doctor, and only 7 percent had undergone genetic testing. Just over one-quarter of participants (26 percent) reported that they thought they should have a colonoscopy every one to two years and 30 percent of endoscopists for these participants recommended screening at this interval—a 65 percent concordance between endoscopist recommendations and participant reports regarding screening intervals.

The researchers found that participants who were recruited because their family member was being seen in a high-risk cancer clinic were 20 percent more likely to report that they had heard of genetic testing and had discussed genetic testing with their provider. However, this knowledge did not translate into higher rates of referral for or completion of genetic testing. Similarly, those recruited from high-risk clinics were more likely to have better knowledge of appropriate screening intervals 24 months after enrollment and were more likely to adhere to colonoscopic screening, suggesting that at-risk families in the general population are not getting needed information, the authors say.

“These findings demonstrate a major deficit in guideline-based care for members of hereditary non-polyposis CRC families in the United States,” write the authors led by Swati Patel, M.D., from University of Colorado (Aurora).