Tuesday, May 3, 2011

New HPV Test to Detect Greater Cancer Risk

On April 20, 2011 Roche Diagnostics announced the FDA’s approved of its new HPV test, cobas. This new test detects the presence of DNA for fourteen high risk strains of the virus. There are a few differences however between cobas and the other HPV tests currently on the market.Roche’s test will check for fourteen of the high risk HPV strains. The Hologic test, Cervista, also tests for these same fourteen strains, while the digene test checks for thirteen.

Once this is completed, the Roche test will then concurrently genotype the specimen for HPV types 16 and 18. These two HPV strains are shown to cause approximately 70 percent of all cervical cancers.

The ATHENA study was utilized to determine the effectiveness of this new test, cobas. The study was conducted throughout the United States and involved a total of 47,000 women. It showed that one in ten women who tested positive for types 16 and 18genotyping had precancerous lesions despite having a negative result on their Pap smears.

Roche representatives, Christoph Majewski , Head of HPV molecular science and Dr. Catherine Behrens, Director of Medical Affairs, state that of the women involved in the ATHENA study with a Pap result of ASCUS (atypical squamous cells of undetermined significance) 90 percent were shown on biopsy to have CIN2/3 lesions. Of those, 46 percent were CIN3.

The National Cancer Institute indicates that 10 percent of women who are positive for HPV types 16 and 18 have been shown to develop CIN3 (cervical intraepithelial neoplasia grade 3) within three years. CIN3/CIS (carcinoma in situ) is the most severe type of abnormality prior to the lesion becoming an invasive cancer.
The current digene HPV test in existence for over ten years does not, at this point, genotype within its 13 panel assay. It has however since its inception performed over forty million tests and had over three-hundred peer review articles with respect to its methods. Both Hologic and Roche have a bit of catching up to do in that respect.

Cervista (the HPV test from Hologic and also approved by the FDA) like cobas, also tests for fourteen high risk strains. While Cervista does not concurrently genotype for 16 and 18 like cobas, they do offer a separate test to genotype for both 16 and 18.

It may seem more convenient to have all testing done relatively simultaneously in one HPV test. However, since much of the cost of testing is ultimately determined by the laboratories performing them, it will be interesting to see just which test will take the lead.