Introduction Lynch syndrome (LS) accounts for most of the inherited endometrial cancers. Screening for mismatch repair (MMR) defects is recommended using immunohistochemistry (IHC) to identify qualifying patients for genetic testing. We report LS screening and genetic testing rates at a tertiary care center with a large minority population.

Methods Retrospective cohort study of patients with newly diagnosed endometrial cancer between January 2014 and June 2022 at the NewYork-Presbyterian Brooklyn Methodist Hospital.

Results 373 patients included. 45% identified as white, 42% black; 8.3% were of Hispanic ethnicity and 18% were non-English speaking. 207(55%) patients were screened using MMR-IHC. 82(40%) of these patients had MMR deficiencies. Of these, 63(77%) received genetic counseling. 62(98%) subsequently underwent genetic testing, and 7(11%) were diagnosed with LS. The rate of LS detected was 1.9%. MMR-IHC testing rates reached 95% in 2021 and 100% in 2022. It was not influenced by race, language, BMI, family history of cancer, or stage. The proportion of patients that received genetic counseling and testing also increased over time (p<0.01). Rates were different by ethnicity (p=0.03), with only 3.0% of patients receiving services identifying as Hispanic. 98% of genetic counseling was performed by a gynecologic oncologist, as opposed to a genetic counselor.

Conclusion/Implications There were no disparities in access to IHC screening in this diverse population, however more work must be done to reach all ethnicities for genetic counseling and testing. The rate of LS detected was less than the known prevalence in endometrial cancer, indicating demographic differences or gaps in screening.

© 2023 American Society of Clinical Oncology, Inc. Reused with permission. This abstract was accepted and previously presented at the 2023 ASCO Annual Meeting. All rights reserved.’