DECISION FOR NON-COMPLETION OF FOLLOWUP AMONG PATIENTS WITH ABNORMAL SCREENING TEST FOR HEREDITARY COLORECTAL CANCER SYNDROME
Lynch Syndrome (LS) is the most common hereditary colorectal cancer (CRC) syndrome. CRCs associated with LS are hallmarked by DNA mismatch repair deficiency (dMMR), and testing tumors for dMMR has been advocated as a screening test for LS. Patients with dMMR CRCs and suspected to have LS undergo genetic counseling, confirmatory germline genetic testing, and specialized clinical genetics care. Completion of this 3-component follow-up clinical pathway remains poorly investigated. We examined the decision associated with completion vs. non-completion of the follow-up genetics care process among patients suspected to have LS.
During 2009-2014, a prospective protocol of universal LS screening tested 1597 consecutive CRCs for MMR status. dMMR CRC was determined by MSI testing and/or immunohistochemistry (IHC). A standardized follow-up clinical pathway was established for patients with dMMR CRCs and included 3 components: 1) genetic counseling at the point of care, 2) confirmatory germline genetic testing, and 3) enrollment in the Familial High-risk Clinic. Clinical and sociodemographic factors were examined to identify risk factors associated with the decision to complete vs. not complete the follow-up clinical pathway.
110 patients with dMMR CRCs were suspected to have LS. The treating physicians triggered a referral to genetic counseling in each case. Eighty-five (77%) of the referred patients completed genetic counseling, while 25 (23%) did not. Non-completion of this component of follow-up was associated with older age at CRC diagnosis (58 vs. 49 years, median; p=0.03), and not having private insurance (44% vs. 22%; p=0.024; 36% of the non-completion patients had Medicare). Among 85 patients who participated in genetic counseling, 75 (88%) completed the recommended confirmatory germline genetic testing, and 62 (83%) of the tested enrolled in the Familial High-risk Clinic. Similarly, non-completion of these two components was associated with older age (55 vs. 49 years, median; p=0.01) and lack of private insurance (48% vs. 27%; p=0.036).
The 3-component follow-up clinical pathway was associated with varying completion rates. It was lowest for genetic counseling, a decision triggered solely by the treating physicians, and highest for confirmatory genetic testing, a decision following genetic counseling. Aligning each care component with joint decision processes that involves both the patient and physician will likely increase follow-up, empower decision-making, and improve resource utilization.