- HPV test detects 14 types of the virus
- Pap test has been first way to diagnose cervical cancer for 60 years
- The HPV test is sensitive, meaning lots of positive results
The FDA announced approval Thursday of the human papillomavirus DNA test as a primary screening method for cervical cancer.
The U.S. Food and Drug Administration initially approved the HPV DNA test in 2011, for use alongside or as a follow-up to a Pap test, but this is the first time it has been green-lighted as a primary screening technique.
The FDA announced approval of the method on Thursday after an FDA advisory committee unanimously recommended in March that the HPV test become the first line of screening for the deadly disease.
The approval is limited to women over the age of 24.
Developed by Roche Molecular Systems Inc., the cobas HPV Test
can be used to see if a woman needs additional screening for cervical cancer and to gather information about her future risk.
The Pap test -- the standard for 60 years -- is designed to look for abnormal squamous cells that could indicate cervical cancer, while the HPV test looks for DNA from the virus. A vaginal swab is required for both the Pap test and the HPV DNA test, so you won't notice a difference at the doctor's office.
"The potential benefit of (the HPV test) is that everybody that has a precancerous change or cervical cancer will have a positive test," said Dr. Kevin Ault, professor at the University of Kansas Medical Center in Kansas City. "You're not going to miss anybody."
There are other HPV tests out there, but this one can detect the most problematic strains -- HPV 16 and 18. The test can also detect DNA from 12 other types of HPV that are associated with an increased cancer risk. HPV causes more than 99% of all cervical cancers.
The problem with any HPV test is that a lot of women -- between 2% and 10% -- will test positive for the virus, Ault said. And most women who get HPV don't develop cervical cancer.
HPV is so common that at least 70% of people who are sexually active will get a genital HPV infection at some point in their lives, according to the National Cancer Institute
"Most people who get HPV only have it for a few months or a year and then it goes away," Ault said. "It's really the people it persists in that are going to the problem."
But how do we know who with HPV will likely develop cervical cancer? Positive results on the HPV test will necessitate further screening, he said. Patients who test positive may have to have a Pap smear as well, and potentially biopsies and other procedures.
"The disadvantage is a lot of people are going to be scared," he said.
If this new test is adopted as the primary screening method, Ault said, doctors can focus their Pap examinations on women who are already known to have HPV.
In most cases, patients who don't have HPV are less likely to need a Pap, which is why the advisory committee felt it best to recommend the Roche test be administered as the first form of detection, women's health experts say.
If both the Pap smear and the HPV test are negative, that would mean the patient essentially has almost no chance of developing cervical cancer in the next five years, Ault said.
"Every year, 12,000 women are diagnosed in the U.S. with cervical cancer. This is especially tragic because cervical cancer is a largely preventable disease, and it is well established that HPV is the cause of almost all cervical cancers worldwide. Women need better access to screening tools that include primary HPV screening in order to reduce their risk of developing cervical cancer," said Dr. Thomas Wright Jr., an expert in gynecology and pathology at Columbia University Medical Center.
Many gynecologists are used to doing routine Pap tests, so the HPV test may take a little while to replace the traditional pap smear, Ault said.
But Thursday's approval of the test does not change current practice guidelines.
Cervical cancer screening guidelines are usually proposed through organizations such as the American Cancer Society or the American College of Obstetricians and Gynecologists. The FDA's role is in approval of the test itself.