Scientists advising the federal government say a Pap test is a good way to screen young and middle-aged women for cervical cancer, and it's only needed once every three years. But they say there is not enough evidence yet to back testing for HPV, the virus that causes the disease.
That's at odds with the American Cancer Society and other groups, which have long said that using both tests can be an option for women over 30.
The groups and the U.S. Preventive Services Task Force separately plan to release proposed guidelines for cervical cancer screening on Wednesday and invite public comment. The task force is the same group that recommended against routine PSA tests to screen for prostate cancer, saying they were doing more harm than good for men at average risk.
Cervical cancer screening is a success story. In the United States, cases and death rates have been cut more than half since the 1970s because of Pap smears — lab exams of cells scraped from the cervix, the gateway to the uterus. The test can find early signs of this slow-growing cancer and treat them before a tumor has a chance to develop.
So "the bar is set pretty high" for a test to replace or supplement Paps, said Dr. Evelyn Whitlock of Kaiser Permanente Northwest's Center for Health Research in Portland, Ore.
Not enough is known about the benefits and especially the harms of HPV testing, concludes a scientific review she led for the task force that was published on Monday in the Annals of Internal Medicine.