Sensitivity of cervico-vaginal cytology in endometrial carcinoma: A systematic review and meta-analysis

Cervico-vaginal cytology is primarily a cervical cancer screening test. The anatomical continuity of the uterine cavity with the cervix makes the Papanicolaou (Pap) test accessible to evaluate signs of disease shed from the endometrium. Our aim was to determine the sensitivity of routine Pap test in endometrial carcinoma detection and its relationship with clinico-pathologic factors. We performed a systematic review of studies reporting Pap test results prior to diagnosis of or surgery for endometrial carcinoma between 1990 and 2018 in PubMed or Web of Science. Two independent reviewers extracted data and assessed study quality using an adapted Newcastle-Ottawa Quality Assessment Scale and Quality Assessment of Diagnostic Accuracy Studies tool. We identified 45 studies including a total of 6599 women with endometrial cancer. Abnormal Pap test results prior to diagnosis of or surgery for endometrial carcinoma were observed in 45% (95% CI, 40%-50%) of study participants. This percentage was significantly higher among those of non-endometrioid histology compared with endometrioid subtypes (77% [95% CI, 66%-87%] vs 44% [95% CI, 34%-53%], respectively; P heterogeneity <.001). Several clinico-pathologic factors were related to a higher percentage of abnormal Pap test results, including high-stage, myometrial invasion >50%, high histological grade, positive peritoneal cytology, presence of lymph node metastasis, cervical involvement, and lymphovascular invasion (P heterogeneity <.05 for all variables). Routine cervical cytology can detect endometrial cancer in almost half of patients, whereas sensitivity is higher among individuals with non-endometrioid histology or more advanced cancers. This review summarizes the current clinical and prognostic value of cervical cytology in endometrial carcinoma. Recent technological developments using molecular biomarkers may improve accuracy for early cancer detection.