Predictive value of the anal cytology for detecting anal intraepithelial neoplasia or worse: A systematic review and meta‐analysis

BACKGROUND: Anal intraepithelial neoplasia (AIN) refers to a precancerous lesion of anal squamous cell carcinoma (SCC). Human papillomavirus (HPV) is considered a crucial risk factor for AIN. Individuals with high-risk sexual behaviour, such as receptive anal intercourse and multiple sexual partners, as well as men who have sex with men exhibit a relatively high rate of AIN. The anal cytology is a screening method for AIN in high-risk individuals, and patients with abnormal anal cytology may benefit from high-resolution anoscopy. This study explored the predictive value of the anal cytology for the detection of AIN or worse (AIN+). METHODS: We searched the databases of PubMed, BioMed Central, Cochrane Library, and Google Scholar for relevant studies. Studies on the diagnostic efficacy of the anal cytology for predicting anal cancer on a per-patient basis were included. We excluded review articles. Either prospective trials or retrospective studies were included. We performed the meta-analysis by using a random-effects model to generate a pooled sensitivity, specificity, and diagnostic odds ratio (DOR). All analyses were performed using the MetaDiSc version 1.4 software (Universidad Complutense, Madrid, Spain). RESULTS: Twelve studies with 2541 participants were retrieved. The meta-analysis of the studies assessing the predictive value of the anal cytology for detecting AIN+ generated a pooled sensitivity of 0.79 (95% confidence interval [CI], 0.77-0.82) and a pooled specificity of 0.66 (95% CI, 0.64-0.69). The pooled DOR for the anal cytology was 5.31 (95% CI, 3.31-8.49). CONCLUSIONS: Our results revealed that the anal cytology might be effective in diagnosing AIN+.