Accuracy of p57(KIP) (2) compared with genotyping to diagnose complete hydatidiform mole: a systematic review and meta‐analysis

BACKGROUND: Distinguishing hydatidiform moles (HMs) from nonmolar specimens and the subclassification of HM are important because complete hydatidiform mole (CHM) is associated with an increased risk of development of gestational trophoblastic neoplasia. However, diagnosis based solely on morphology has poor inter‐observer reproducibility. Recent studies have demonstrated that the use of p57(KIP) (2) immunostaining improves diagnostic accuracy for CHM. OBJECTIVES: To evaluate the accuracy of p57(KIP) (2) immunostaining compared with molecular genotyping for the diagnosis of CHM. SEARCH STRATEGY: Major databases were searched from inception to March 2017 using the terms ‘hydatidiform mole’, ‘p57’, and ‘genotyping’, with their variations, and the search limit for the relevant study design. SELECTION CRITERIA: Any cross‐sectional study, case series, case–control study, cohort study, or clinical trial that evaluated the accuracy of p57(KIP) (2) immunostaining for the diagnosis of CHM compared with genotyping was included. Case reports, narrative reviews, expert opinions, and animal testing were excluded. DATA COLLECTION AND ANALYSIS: Extracted accuracy data were tabulated and pooled using a hierarchical bivariate random effects model. MAIN RESULTS: Bivariate meta‐analysis produced a summary sensitivity of 0.984 (95% CI: 0.916–1.000) and specificity of 0.625 (95% CI: 0.503–0.736) with significant heterogeneity for specificity (I (2) = 71.8, chi‐square P = 0.029). The pooled summary diagnostic odds ratio was 56.54 (95% CI: 11.03–289.74) with no heterogeneity (I (2) = 0.00%, chi‐square P = 0.67). The diagnostic performance of the test was high with an area under the curve of (AUC) 0.980. CONCLUSIONS: p57(KIP) (2) immunostaining is accurate when diagnosing CHM. It can be used as an adjunct test in a combination algorithmic approach. TWEETABLE ABSTRACT: A meta‐analysis to evaluate the accuracy of p57(KIP) (2) compared with genotyping to diagnose CHM.