Human papillomavirus (HPV) in an Icelandic population: the role of HPV DNA testing based on hybrid capture and PCR assays among women with screen-detected abnormal Pap smears.

Abstract

This study was based on 358 cases with abnormal smears referred for colposcopy and HPV DNA testing. We analysed: 1) the frequency of different grades of cyto- and histopathologic findings; 2) the frequency and relative amount of HPV DNA with the hybrid capture assay (HCA) in swabs, and the frequency of HPV with PCR in swabs (-S) and biopsies (-B); and 3) the frequency of HPV types according to the grade of the cyto- and histopathologic findings. Of all cases, 95% were positive with all HPV tests combined. The HCA (HPV: 16, 18, 31, 33, 35, 45, 51, 52 and 56) and the PCR-S and PCR-B (HPV: 16, 18, 31, 33 and 35) tests for high-risk HPV exhibited sensitivities of 57%, 56% and 48%, respectively. The high-grade smears and the high-risk PCR-S HPV had about 80% sensitivity for histologic high-grade lesions compared with around 70% for HCA and the PCR-B. Combining the high-grade smears and the high-risk HPV increased the sensitivity to 93-96%. Among the cervical intraepithelial neoplasia I (CIN I) and the atypical squamous cells of undetermined significance (ASCUS) smears the sensitivity of high-risk HPV for high-grade histologic lesions was 63% for the HCA and 79% for the PCR-S. No correlation was found between the relative amount of HPV DNA detected by HCA and the grade of cyto- and histological lesions. We conclude that the results strongly indicate that HCA is less sensitive than PCR in the diagnosis of high-risk HPV, that swabs are more sensitive than biopsies as a sampling method, that high-risk HPV and high-grade smears are complementary for the diagnosis of high-grade histologic lesions and that the present role of HPV testing in screening could be limited to identifying women with low-grade smears and koilocytotic or low-grade colposcopic biopsies that are at risk of concealing or developing high-grade histologic lesions.