March 14, 2014 | by Roberta Nichols
If the new recommendations of a Food and Drug Administration (FDA) advisory panel are widely adopted, HPV testing eventually may replace the Pap test as the primary way to detect cervical cancer. City of Hope cervical cancer expert says the recommendations have merit.
The Pap test – named for its inventor, pathologist George Papanicolaou – is designed to identify cancers and precancers in the cervix, and has been the standard screening for cervical cancer during the past 60 years. The screening is credited with dramatically lowering death rates.
The new test, developed by Roche Molecular Systems, detects HPV's DNA. HPV, or human papillomavirus, is now known to cause nearly all cervical cancer cases.
The 13 academic gynecologists, pathologists and microbiologists on the FDA’s Medical Devices Advisory Committee Microbiology Panel unanimously concluded that the Roche test is safe and effective as a first-line screening for cervical cancer. It reviewed data from the ATHENA trial, which included more than 47,000 women.
Until now, DNA testing primarily has been used in tandem with the Pap test for screening, and as a follow-up tool when Pap test results were inconclusive. The panel recommended that the Roche test be used alone as the primary screening for women 25 and older.
Many physicians don’t see the Pap test disappearing anytime soon though, particularly since it cut death rates by 70 percent between 1955 and 1992.
As the New York Times' Andrew Pollack observed, “Assuming the F.D.A. itself agrees with its advisory committee and approves the use of Roche’s test, it would become just another option, not a replacement for the older testing regimens. And many doctors will not adopt the new test unless professional societies recommend it in guidelines, which could take years.”
Still, doctors seem encouraged to have another trusted screening option. After all, detecting anomalies early – no matter what test is used – is what saves women’s lives.
David Chelmow, M.D., spokesperson for the American College of Obstetricians and Gynecologists, said the college “strongly supports further improving cervical cancer screening through the introduction of new paradigms such as HPV testing for primary screening.”
“The use of the Pap test and HPV test in tandem, or co-testing, is currently the preferred method of cervical cancer screening in women over 30, so ob-gyns generally use the combination,” he told CNN. “The use of the HPV test as a first-line screen is promising, and appears better than the Pap test used by itself. The real question is how it compares to co-testing, which is not yet clear.”
Sharon Wilczynski, M.D., Ph.D., professor of pathology and cytology at City of Hope, who was involved in early studies to establish HPV as the cause of cervical cancer, is also intrigued by the new recommendation.
“I really do see HPV testing as primary screening for cervical cancer becoming the standard in the future, particularly with HPV vaccination and a decrease in HPV disease. The molecular testing is going to be much more efficient in identifying women at risk than the Pap ever could.
“There are several studies in the literature that have found that testing women for the presence and persistence of the virus (HPV) is superior to the Pap smear in detecting women at risk for cervical cancer. But it is less specific, and many women will test positive for the virus but will not have disease,” she cautioned.
“HPV infection is very common in young women initiating sexual activity, but most will clear the infection and only a small percentage will develop persistent HPV infection and high-grade dysplasia that potentially progresses to cancer,” she continued.
There are still many issues to be resolved before the new test is widely implemented, Wilczynski said. “These include at what age to start testing, how often to test, intervals between testing, the best molecular test to use and how to follow up the HPV-positive test.
“Another unknown is how HPV vaccination against the two common high-risk HPV types (16 and 18) will affect the distribution of HPV types in the population and in dysplasias (precursors to cervical cancer),” she said.
“And finally, we should not forget that in the U.S., about 12,000 cases of cervical cancer occur each year, and 60 percent occur in women who have never had a Pap smear or have not been screened in the last five years.
“Access to screening," she added, "is still a big problem."
Learn more about City of Hope's gynecologic cancers program.