Pap smears to screen for cervical cancer could soon be replaced with a new, more reliable screening test that was recently approved by the U.S. Food and Drug Administration. The screening test, the cobas human papillomavirus (HPV) DNA test, can be a primary screening method for cervical cancer.
Typically, an HPV infection clears up on its own and doesn't lead to health problems. But, about 10 percent of women infected with high-risk HPV develop a persistent infection that may put them at risk of cancer.
Developed by Roche Molecular Systems, the cobas HPV test can detect 14 types of HPV that present high risk of cervical cancer. Specifically, the test identifies HPV 16 and HPV 18 -- the two types that are responsible for around 70 percent of cervical cancer cases.
The cobas HPV test can also be used to see if a woman needs additional screening for cervical cancer and to gather information about her future risk. The FDA provides guidelines for how the test should be used.
According to the FDA, if the cobas HPV test detects HPV types 16 or 18, women should have a colposcopy, which uses a device to illuminate and magnify the cervix so a doctor can find abnormal areas that could be cancers or pre-cancers.
If the cobas HPV test detects one of the other 12 HPV types, women should have a Pap test to determine the need for a colposcopy. Women who test negative for all 14 types should repeat the test in three years.
The FDA initially approved the cobas HPV test in 2011, for use alongside or as a follow-up to Pap smears. However this is the first time it has been approved as a primary screening technique.
Whether or not doctors will accept using the cobas HPV test first instead of a Pap test depends upon both the clinical trial data supporting it and on doctors and patients being educated about it.
The study included more than 40,000 women 25 years of age and older who had either Pap tests or HPV testing. It found that women who had just the HPV test initially were more likely to have any cancers detected and were less likely to have unnecessary biopsies than those who had only Pap smears.