Endocervical sampling in women with suspected cervical neoplasia: a systematic review and meta-analysis of diagnostic test accuracy studies

OBJECTIVE: Endocervical sampling in women with suspected cervical neoplasia can be performed by either endocervical brush or endocervical curettage. This study aimed to estimate the diagnostic accuracy, discomfort, and number of inadequate samples with either test.

DATA SOURCES: Four bibliographic databases were searched on June 9, 2022, with no date or language restrictions.

STUDY ELIGIBILITY CRITERIA: We included all diagnostic studies and randomized clinical trials that compared the endocervical brush with endocervical curettage in women with an indication for colposcopy.

METHODS: The review protocol was registered on the International Prospective Register of Systematic Reviews (PROSPERO) (CRD42021222406). Two authors independently screened studies, extracted data, performed the risk-of-bias assessment (Quality Assessment of Diagnostic Accuracy Studies-2), and rated the certainty of the evidence using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology. A meta-analysis of diagnostic test accuracy was performed using a bivariate random-effects model.

RESULTS: We included 7 studies: 4 diagnostic cohort studies and 3 randomized clinical trials. The reference standard was conization or hysterectomy. Risk of bias and concern about applicability were high for some of the studies in patient selection and flow and timing. Overall pooled sensitivity was 81% (95% confidence interval, 48-95; 799 women; 7 studies; low quality of evidence) for endocervical brush and 70% (95% confidence interval, 42-89; 761 women; 7 studies; low quality of evidence) for endocervical curettage. Overall pooled specificity was 73% (95% confidence interval, 36-93; 799 women; 7 studies; low quality of evidence) for endocervical brush and 81% (95% confidence interval, 56-94; 761 women; 7 studies; low quality of evidence) for endocervical curettage. The risk ratio for inadequate samples with endocervical curettage compared with endocervical brush was 2.53 (95% confidence interval, 0.58-11.0; P=.215; low-certainty evidence). Two studies reported on patient discomfort; one found less discomfort in the endocervical brush group, and the other found no difference.

CONCLUSION: No difference was found between endocervical brush and endocervical curettage in diagnostic accuracy, inadequate sampling rate, and adverse effects based on low-quality of evidence. Variation in the characteristics of women and the resulting diagnostic pathways make the external validity limited.