Mutational analysis of cervical cytology improves diagnosis of endometrial cancer: A prospective multicentre cohort study

Endometrial carcinoma (EC) is traditionally diagnosed by a histopathological assessment of an endometrial biopsy, leaving up to 30% of patients undiagnosed due to technical failure or an inadequate amount of tissue. The aim of the current study is to assess whether mutational analysis of cervical cytology or pipelle endometrial biopsies improves the diagnostic accuracy of traditional histopathological diagnosis of EC. This prospective multicentre cohort study included patients surgically treated for EC or a benign gynaecological condition (control group). A Pap brush sample, cervicovaginal self‐sample, pipelle endometrial biopsy and surgical specimen of either the EC or normal endometrium were obtained. A targeted next‐generation sequencing panel was used to analyse these samples for mutations in eight genes. Sensitivity, specificity and predictive values were calculated. Fifty‐nine EC patients and 31 control patients were included. In these patients, traditional histopathological diagnosis by pipelle had a sensitivity of 79% and a specificity of 100%. For EC patients, 97% of surgical specimens contained at least one mutation. Mutational analysis of Pap brush samples, self‐samples and pipelle endometrial biopsies yielded a sensitivity of 78, 67 and 96% with a specificity of 97, 97 and 94%, respectively. Combining one of these three methods with histopathological pipelle endometrial biopsy evaluations yielded a sensitivity of 96, 93 and 96%, respectively. Our study has shown that mutational analysis of either cervical cytology or pipelle endometrial biopsies improves diagnosis of EC. Prospective validation will support implementation in clinical practice. What's new? Diagnosing endometrial cancer generally relies on histopathological analysis of endometrial biopsy samples. However, these tests are inconclusive in up to 30% of patients. To find a better way, these authors tested whether genetic analysis of endometrial or cervical samples could boost the diagnostic accuracy of the test. They tested 59 EC patients and 31 controls for 8 different genetic mutations using tissue from either Pap brush samples, pipelle biopsies, or self‐samples. Combining histopathology with mutation testing increased sensitivity from 79% to 93‐97%.