Clinical Usefulness Of Universal Screening For Lynch Syndrome In Gynecological Cancer Of A Single-Center Investigation

Reportedly, Lynch syndrome (LS) accounts for 2-3% of endometrial and colorectal cancer. Although clinical screening, Amsterdam or Bethesda criteria are used to identify patients at risk of LS, these screening tools are limited by their low sensitivity. Currently, immunohistochemical (IHC) evaluation is preferred to determine the expression of the four mismatch repair proteins (MLH1, MSH2, MSH6, and PMS2) because of its cost-effectiveness and high concordance. We report the results of IHC and genetic counseling performed in patients with uterine corpus cancer, ovarian cancer, and cervical adenocarcinoma. This study included 73 patients diagnosed with endometrial carcinoma (34 patients), ovarian carcinoma (31 patients), and cervical adenocarcinoma (8 patients), who were treated at a single hospital between 2018 and 2020. Informed consent was obtained from all patients. We performed IHC evaluation for universal screening of tumors. Genetic counseling was recommended for patients with mismatch repair protein (MMR) deficiency. MMR proteins disappeared in four patients (11.7%) with endometrial carcinoma but not in patients with ovarian and cervical cancer. Although the four patients with MMR deficiency were recommended to undergo genetic counseling, three patients did not undergo genetic counseling. Only one patient without a family history suspicious for LS received genetic counseling and did not choose a definitive diagnosis owing to the cost. We identified four patients with endometrial cancer associated with MMR deficiency. Universal screening can be useful for screening of LS, particularly in patients with endometrial cancer.