Meta-analysis of the accuracy of p16 or p16/Ki-67 immunocytochemistry versus HPV testing for the detection of CIN2+/CIN3+ in triage of women with minor abnormal cytology.

BACKGROUND: Women with atypical squamous cells of undetermined significance (ASC-US) can be triaged accurately with a high-risk human papillomavirus (hrHPV) test to identify those who need a referral. However, the triage of low-grade squamous intraepithelial lesion (LSIL) with hrHPV testing has very low specificity. Overexpression of p16, with or without Ki-67, indicates neoplastic transformation of human papillomavirus-infected cervical cells and may more accurately predict underlying cervical intraepithelial neoplasia of grade 3 or worse (CIN3+).

METHODS: A literature search was conducted in 3 bibliographic databases. Studies were selected if they included women with ASC-US or LSIL who were triaged with dual staining (p16/Ki-67) and/or p16 staining and, if available, with a comparator hrHPV test to detect cervical intraepithelial neoplasia of grade 2 or worse (CIN2+) or CIN3+.

RESULTS: Thirty-eight studies were eligible. The sensitivity of p16 staining for CIN3+ was significantly lower than that of hrHPV DNA testing (ratio for ASC-US, 0.87; 95% confidence interval [CI], 0.78-0.97; ratio for LSIL, 0.86; 95% CI, 0.80-0.93). In contrast, the specificity of p16 staining was substantially higher with relative specificities of 1.60 (95% CI, 1.35-1.88) and 2.29 (95% CI, 2.05-2.56) for ASC-US and LSIL respectively. Dual staining was as sensitive as hrHPV DNA testing but was more specific (ratio for ASC-US, 1.65; 95% CI, 1.42-1.92; ratio for LSIL, 2.45; 95% CI, 2.17-2.77).

CONCLUSIONS: This meta-analysis confirms that p16 staining and p16/Ki-67 staining are more specific for CIN2+/CIN3+ than hrHPV DNA testing. Although p16 staining is less sensitive for CIN3+ than hrHPV DNA testing, dual staining has similar sensitivity.