Diagnostic accuracy of cytology for the detection of endometrial cancer in urine and vaginal samples

TLDR

Postmenopausal bleeding prompts invasive testing, yet 90–95 % of women do not have endometrial cancer. The study seeks to validate a simple, non‑invasive cytology test that accurately detects endometrial cancer and could replace invasive investigations. In a cross‑sectional study of 103 cancer patients and 113 women with unexplained postmenopausal bleeding, urine and vaginal cytology achieved 91.7 % sensitivity and 88.8 % specificity, correctly identifying 91 endometrial cancers and a few others, with an 11.2 % false‑positive rate.

Abstract

Abstract Postmenopausal bleeding triggers urgent investigation by sequential invasive tests that are avoidable for the 90–95% of women who do not have endometrial cancer. A simple, non-invasive tool that accurately identifies cancer and safely reassures healthy women could transform patient care. Here we report, in a cross-sectional diagnostic accuracy study of 103 women with known cancer and 113 with unexplained postmenopausal bleeding, that urine and vaginal cytology has a combined sensitivity of 91.7% (95% CI 85.0%, 96.1%) and specificity of 88.8% (81.2%, 94.1%) for gynecological cancer detection. Cytology identifies 91 endometrial, two fallopian tube and one cervical cancer from 103 known cancer cases. In women with unexplained postmenopausal bleeding, cytology identifies all four endometrial cancers and three others (cervical, ovarian and bladder), for a 12/107 (11.2%) false positive rate. We show proof-of-principle that endometrial cancer can be detected in urine and vaginal fluid. Prospective validation of these findings will support incorporation of this non-invasive test into clinical practice.