Pap Test Still Best for Cervical Cancer Screening, Experts Say
Posted Oct 17 2011 1:00pm
HPV test also works well but gives more false-positives, studies show.
By Denise Mann HealthDay Reporter
MONDAY, Oct. 17 (HealthDay News) --Human papillomavirus (HPV) testing isn't likely to replace conventional Pap tests as a cervical cancer screening tool among women older than 30, a new report suggests.
The U.S. Preventive Services Task Force published recommendations for cervical cancer screening in 2003, and researchers are now seeking to fine-tune these guidelines. The results from two evidence reviews, both published Oct. 18 in the Annals of Internal Medicine, seek to clarify and improve upon these guidelines.
"Cervical cancer screening is a public health success story," said study author Dr. Evelyn P. Whitlock, a preventive medicine specialist at Kaiser Permanente Center for Health Research in Portland, Ore. "The number of women dying from cervical cancer has been cut in half due to regular screening."
But "there are still about 12,000 women diagnosed with cervical cancer every year and 4,000 women die from cervical cancer each year," she said. "We need to continue to improve so we have a fully successful screening program. We are trying to improve on success and that is a pretty high bar."
To compare the two types of testing, the researchers analyzed four studies they deemed of fair-to-good quality, encompassing nearly 142,000 women.
HPV causes many cases of cervical cancer, and incorporating HPV testing into cervical cancer screening programs may catch more at-risk women. However, the researchers found that HPV testing, on its own, yields too many false positives which results in unnecessary testing, anxiety and health care costs for many women.
According to the new report, HPV testing is more sensitive, but less specific than the Pap test, Whitlock said. "This means that more women who have nothing wrong with them will test positive with HPV testing, and this may cause potential harm," she said.
During a Pap test, a doctor scrapes cells from a woman's cervix and a laboratory examines these cells for abnormalities. When a type of Pap test called a liquid-based cytology test is performed, testing for HPV can be performed at the same time.
Dr. Elizabeth A. Poynor, a gynecologic oncologist and pelvic surgeon at Lenox Hill Hospital in New York City, said this is a work in progress. "We are still learning how to incorporate HPV testing into our current algorithm," she said. "Women need to ask their physician which screening strategy is best for them based on their personal risk factors."
Another review article looked at the appropriate ages to initiate and discontinue cervical cancer screening. The authors conclude that screening for cervical cancer should continue to begin at age 21. If a woman age 65 or older has had an adequate number of normal Pap test results and is not considered high risk for cervical cancer, she can stop screening at age 65. Older woman who are considered at high risk for cervical cancer include those who have had previous high-grade cervical lesions or a history of cervical cancer.
Dr. Mark Wakabayashi, chief of gynecologic oncology at the City of Hope Cancer Center in Duarte, Calif., said that the real issue is that some women never get either test. "The ones who don't get Pap tests are the ones who are dying from cervical cancer," he said. "We are trying to be more cost-effective with our screening for cervical cancer, but we don't want to mess with success."
(SOURCES: Evelyn P. Whitlock, M.D., MPH, preventive medicine specialist, Kaiser Permanente Center for Health Research, Portland, Ore.;
Mark Wakabayashi, M.D., chief, gynecologic oncology, City of Hope Cancer Center, Duarte, Calif,;
Elizabeth A. Poynor, M.D., gynecologic oncologist and pelvic surgeon, Lenox Hill Hospital, New York City; Oct. 18, 2011, Annals of Internal Medicine