The role of HPV testing in patients with possible high-grade cervical cytology

Triage of ASC-H: A meta-analysis of the accuracy of high-risk HPV testing and other markers to detect cervical precancer

BACKGROUND

Women with a cytological diagnosis of atypical squamous cells, cannot exclude high-grade squamous intraepithelial lesion (ASC-H) are usually immediately referred for colposcopy. However, triage may reduce the burden of the diagnostic workup and prevent overtreatment.

METHODS

A meta-analysis was conducted to assess the accuracy of high-risk human papillomavirus (hrHPV) testing and testing for other molecular markers for the detection of grade 2 cervical intraepithelial neoplasia or worse (CIN2+) or grade 3 cervical intraepithelial neoplasia or worse (CIN3+) in women with ASC-H. An additional question that was assessed was whether triage would be useful in light of the relatively high pretriage probability of underlying precancer.

RESULTS

The pooled absolute sensitivity and specificity of the Hybrid Capture 2 (HC2) assay for CIN2 + (derived from 19 studies) were 93% (95% confidence interval [CI], 89%-95%) and 45% (95% CI, 41%-50%), respectively. p16(INK4a) staining (only 3 studies) had similar sensitivity (93%; 95% CI, 75%-100%) but superior specificity (specificity ratio, 1.69) to HC2 for CIN2+. Testing for paired box 1 gene methylation (only 1 study) showed a superior specificity of 95% (specificity ratio, 2.08). The average pretest risk was 34% for CIN2 + and 20% for CIN3+. A negative HC2 result decreased this to 8% and 5%, respectively, whereas a positive result upgraded the risk to 47% and 28%, respectively.

CONCLUSIONS

Because of the high probability of precancer with a diagnosis of ASC-H, the utility of triage is limited. The usual recommendation for referring women with ASC-H for colposcopy is not altered by a positive triage test, whatever test is used. A negative hrHPV DNA or p16(INK4a) test may allow repeat testing, but this recommendation will depend on local decision thresholds for referral.

Increase in viral load, viral integration, and gain of telomerase genes during uterine cervical carcinogenesis can be simultaneously assessed by the HPV 16/18 MLPA-assay

Oncogenic human papillomavirus (HPV) infection is the most important risk factor in cervical carcinogenesis cases; high viral loads, viral integration into the host genome, and gain of the telomerase-related genes, TERT and TERC, are all factors associated with progression to cancer. A recently developed multiparameter HPV 16/18 multiplex ligation-dependent probe amplification (MLPA) assay, which allows the simultaneous assessment of these factors, was applied to a series of 67 normal and (pre)malignant frozen uterine cervical samples, as well as to 91 cytological preparations, to test the ability of the MLPA assay to identify high-risk lesions on the basis of these factors. Validation was performed using quantitative PCR, the PapilloCheck and fluorescence in situ hybridization. Only 5 out of 37 normal tissue samples or low-grade cervical lesions (ie, CIN1 and condyloma) showed either an HPV16 viral load higher than 25 copies per cell, viral integration, and/or gain of one of the telomerase-related genes, whereas for the high-grade cervical lesions, one or more of these risk factors was found in 25 of 30 cases. The HPV MLPA assay showed a sensitivity of 83% and a specificity of 86% in frozen cervical specimens. Furthermore, the feasibility of the MLPA assay was shown for cytological samples, where in 57% of high-grade squamous intraepithelial lesion cases, the high-risk factors were detected using this assay.