DNA Testing Produces Sensitive Assay for Human Papillomavirus

Human papillomavirus (HPV) testing for HPV16 and HPV18 DNA has been introduced to improve the sensitivity and positive predictive value (PPV) of the assay.

Cytology-based screening for cervical cancer is now considered inefficient because of low sensitivity, and many repeated screenings may be needed for increased sensitivity and is being replaced my molecular tests.

A study carried out under the auspices of the American Society for Clinical Pathology Institute (Washington DC, USA) has compared liquid-based cytology testing versus separate testing for HPV16 and HPV18 DNA as well as co-testing to examine the sensitivity and PPV of the different approaches. Liquid-based cytology and HPV DNA testing with two first-generation assays, Amplicor HPV test and Linear Array HPV genotyping test; and individual HPV16 and HPV18 detection by use of the second-generation cobas HPV test were performed on all cervical specimens. The cobas HPV test is a fully automated HPV DNA test that detects in three separate channels: HPV16 individually, HPV18 individually, and a pool of 12 other HPV genotypes.

Of 47,208 women enrolled from May 27, 2008, to August 27, 2009, a total of 41,955 met the eligibility criteria, and 40,901 (97%) had valid cobas HPV and liquid-based cytology test results. Of the 40,901 women, cytology results were abnormal in 2,617 (6%), 4,275 (10%) tested cobas HPV positive, and 431 women were diagnosed with cervical intraepithelial neoplasia grade 2 (CIN2) or worse and 274 with CIN3 or worse. For detection of CIN3 or worse among women who underwent colposcopy, the cobas HPV test was more sensitive than liquid-based cytology testing, 92.0% versus 53.3%, respectively. Adding liquid-based cytology to HPV testing increased sensitivity for CIN3 or worse to 96.7%, but at the cost of increasing the number of screen positives by 35.2%.

Three DNA tests for carcinogenic or high-risk HPV have been approved by the US Food and Drug Administration (FDA; Silver Springs, MD, USA): Hybrid Capture 2 (Qiagen; Gaithersburg, MD, USA), Cervista HPV HR (Hologic; Bedford, MA, USA), and the cobas HPV test (Roche Molecular Systems; Pleasanton, CA, USA). The authors concluded that HPV testing with separate HPV16 and HPV18 detection could provide an alternative, more sensitive, and efficient strategy for cervical cancer screening than do methods based solely on cytology. The study was published in September 2011 in the journal Lancet Oncology.

Related Links:
American Society for Clinical Pathology Institute
US Food and Drug Administration
Roche Molecular Systems