Testing for human papillomavirus (HPV) is an integral part of equivocal cervical cytology triage. Clinical validation of non-FDA (Food and Drug Administration)-approved methods is therefore important because of the high volume of such tests and the implications for missed high-grade lesions if test performance is not optimal.
A preinitiation study and 17 months of follow-up data using Hybrid Capture II (HC II) HPV detection with SurePath (SP) sample collection were analyzed. Results of HPV tests on abnormal cytology samples were collected and compared with follow-up results. HPV-positive rates were determined in cases of low-grade squamous intraepithelial lesion (LSIL) and high-grade squamous intraepithelial lesion (HSIL), and follow-up rates of cervical intraepithelial neoplasia (CIN) were determined in HPV-positive and -negative cases of atypical squamous cells of unknown significance (ASC-US). Rates were compared with published data using FDA-validated methods.
The preinitiation study showed the test method to be 100% sensitive for the detection of LSIL (20 cases) and HSIL (8). The ASC-US follow-up study (2319 cases with 625 having biopsy results) showed that the rate of CIN III+ in HPV +/- cases was 7.8%/1.4%, and of CIN II+ was 17.5%/4.3%, respectively. The positive predictive values/negative predictive values (PPV/NPVs) (CIN II+) for the test were 17.5%/95.7%, respectively.
Published FDA-validated HPV testing follow-up data show that the expected rates of CIN III+ and CIN II+ in the HPV-negative ASC-US population are 1.4% and 5%, respectively, with PPV/NPVs (CIN II+) of 20%/99%, respectively. By comparison, the present data using HC II with SP show strong similarity, indicating clinical validity for the use of this method.