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Women should undergo fewer Pap tests for cervical cancer, medical group says

This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American


Just days after the release of controversial new guidelines recommending against routine mammograms for most women under 50, a different group of medical professionals has announced that the frequency of Pap tests for cervical cancer detection should also be decreased for most women.

The new recommendations, published November 20 by the American College of Obstetricians and Gynecologists in Obstetrics & Gynecology, state that women need not get the test until they are 21 years old and should only need the test every two years (and if, after 30, they have three clear tests in a row, women can get the exam only once every three years). Current guidelines encourage women to get the test every year starting three years after becoming sexually active (or at 21 if that comes first). Women known to be at higher risk (those with compromised immune systems or have had other abnormal tests) are still advised to seek more regular tests.


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"The tradition of doing a Pap test every year has not been supported by recent scientific evidence," Alan Waxman, a professor of obstetrics and gynecology at the University of New Mexico who also headed the committee to review the practices, said in a prepared statement. The test is credited with bringing about a 50 percent drop in the rate of cervical cancer in the U.S. since the 1970s. Waxman still concludes that "a review of the evidence to date shows that screening at less frequent intervals prevents cervical cancer just as well, has decreased costs, and avoids unnecessary interventions that could be harmful," he said.

This year, some 11,270 cases of invasive cervical cancer will likely be diagnosed in the U.S. and about 4,070 women will die from it, according to the American Cancer Society. However, upwards of 4 million Pap smears come back as "abnormal" each year, per the National Cancer Institute, a number, Waxman asserted, that causes both unnecessary anxiety and excessive treatment. 

Those behind the new standards assert that cervical cancer is so slow to grow that less frequent testing would likely still catch abnormalities before the condition became more serious. And even though the sexually transmitted virus that can cause the cancer, human papillomavirus (HPV), is on the rise, younger women can often fight off a would-be cancerous infection without surgery, according to the organization. The advent of the HPV vaccine also promises to cut rates of the virus in the future.

The medical group also contends that cutting back on Pap tests is more important than reducing mammograms (which they oppose), as unnecessary treatment for precancerous lesions can lead to an increased rate of premature and cesarean section births.

"We really felt that the downsides of more frequent screening outweighed any benefits," Waxman told the Washington Post. "More testing is not always more intelligent testing."

These changes are similar in spirit to those newly issued for mammography by the U.S. Preventive Services Task Force on November 16. The task force's breast cancer screening guidelines push back the age of first recommended mammogram from 40 to 50 and advises that the exams are necessary for most women only every two years, rather than annually as had previously been advised.

Both revisions have drawn criticism from some doctors and advocacy groups while also raising suspicion from those critical of the Obama administration's health care proposals, which aim to reduce health care spending by cutting down on some procedures.

In its defense, the American College of Obstetricians and Gynecologists noted that the project to assess the guidelines had been in the works since 2007, according to the Associated Press. "There's no political agenda with regard to these recommendations," Cheryl Iglesia, who chaired the panel, told The New York Times, also noting that the timing of the two announcements was coincidental.

Image courtesy of iStockphoto/Rainbowphoto