Screening of Endometrial Cancer Related to Lynch Syndrome in China by Suction Curettage-Based Cytology and Histology: A Retrospective Study

OBJECTIVE: To explore the feasibility of sampling Chinese patients by suction curettage for cytological and histological screening of endometrial cancer related to Lynch syndrome. METHODS: This retrospective study enrolled patients who underwent endometrial biopsy at our hospital between May 2018 and January 2019. Endometrial sampling (cytological and micro-histological specimens) was conducted by suction curettage. The gold standard for diagnosis was traditional sharp dilation and curettage (D&C). The sensitivity, specificity, and diagnostic accuracy of cytology, micro-histology, and the combination of cytology and micro-histology were calculated. Additionally, receiver operating characteristic (ROC) analysis was used to evaluate the diagnostic efficiency of three screening methods. Mismatch repair proteins were further detected using immunohistochemistry (IHC) in endometrial cancer. RESULTS: This retrospective finally enrolled 100 patients, which satisfactory samples were obtained from 96 patients for liquid-based cytology and 93 patients for microtissue histology. The concordance rates with D&C, sensitivity, and specificity were 94.8%, 76.9%, and 97.5% for liquid-based cytology, 96.8%, 84.6%, and 98.8% for microtissue histology, and 99.0%, 92.3%, and 100.0% for liquid-based cytology and microtissue histology combined, respectively. The AUC of ROC curves in liquid-based cytology, microtissue histology, and the combined methods for diagnostic ability were 0.873, 0.917, and 0.962, respectively. Absence rates of MLHl, MSH2, MSH6, and PMS2 proteins were 15.3% (2/13), 0% (0/13), 7.7% (1/13), and 15.3% (2/13) in the 13 endometrial cancer samples. CONCLUSION: Liquid-based cytology and microtissue histology samples from suction curettage combined IHC are useful for endometrial cancer screening.