258 Screening of Colorectal or Uterine Cancers for Lynch Syndrome Should Be Limited to Younger Patients

Abstract

INTRODUCTION: Universal screening of colorectal and uterine cancers is an effective strategy for diagnosis of Lynch syndrome, but the utility of testing for Lynch syndrome in older patients remains unclear. METHODS: We conducted a single- center study in which all patients with a diagnosis of colorectal or uterine cancer between January 1, 2016 to June 30th, 2018 were included. Specialized text-based search of the pathology lab information systems identified the patients. To capture all patients, the search results were tallied with the local cancer center database. A structured RedCap electronic database was created to systematically collect data about demographics, PREMM scores, genetic testing and a detailed 3-generation family pedigree. All patients underwent screening for lynch syndrome using immunohistochemical or microsatellite instability-based testing. Final diagnosis of Lynch syndrome in patients with abnormal screening was based on well- established commercial assays. The yield of Lynch syndrome was compared across five age groups: ≤50, 50–59, 60–69, 70–79, and >80. Statistical analysis was performed using ANOVA and Student's T-test. RESULTS: Of a total of 737 patients with either colorectal or uterine cancer (demographics shown in Table 1), the final diagnosis of Lynch syndrome was made in 2.7% (20/737). As Table 2 shows, 90% of the patients diagnosed to have Lynch syndrome were under 60 years of age. The two cases of Lynch syndrome in the age groups 60–69 and 70–79 had PREMM scores of >5%. All of the colorectal or uterine cancers after age 80 tested negative for Lynch syndrome. CONCLUSION: Screening of colorectal or uterine cancers for Lynch syndrome should be limited to patients less than age 60 or with abnormal PREMM scores in patients >60. Lynch screening should not be performed after age 80. If confirmed by further studies, our results could further streamline the current recommendation of universal screening of all colorectal and uterine cancers for Lynch syndrome and lead to cost savings.