Lynch Syndrome Identification in Endometrial Cancer Patients: Should Universal Screening be Used for all Histologies?

Background: There is an increased proportion of non-endometrioid histologies in Lynch syndrome-associated compared to sporadic endometrial cancer; however, screening recommendations do not differ between type I and type II cancers. Objective: Our objective was to examine the frequency of Lynch syndrome identified in type I and type II endometrial cancers and their associated characteristics. Methods: We reviewed patients with type I and type II endometrial cancer who were screened for Lynch Syndrome or referred for genetic testing according to an age and family history-based screening protocol. All patients were seen and treated at a large academic institution affiliated with a county safety-net hospital. Clinical, pathologic, immunohistochemistry, and germline genetic testing results were obtained as well as the choice of genetic screening approach, personal and family history, and compliance with testing were assessed. Results: 234 women with type I and 29 patients with type II endometrial cancer were identified. Lynch syndrome was diagnosed in a total of eight (3.4%) type I endometrial cancer patients, all identified after age-based tumor screening. In type II endometrial cancer group, three (10.3%) patients had Lynch syndrome. One was referred for testing after abnormal immunohistochemistry screening under age 60. The other two were >60 years old and identified after abnormal immunohistochemistry screening performed on physician’s request. Conclusion: Age-based screening may not diagnose Lynch Syndrome in women with type II endometrial cancers. Our findings underscore the need for a universal screening approach in patients with type II endometrial cancers, even in a low-resource population.