Guidelines Suggest Less Frequent Screening for Cervical Cancer

Oct. 19, 2011 -- New federal guidelines are urging doctors to back off annual cervical cancer screening for most women. Instead the recommendations say most women between 21 and 65 years old should only be screened every three years, and that more frequent screening may do more harm than good.

The draft guidelines come from the U.S. Preventive Services Task Force (USPSTF). They're the first new recommendations on cervical cancer screening to come from the agency since 2003.

Meanwhile, several other organizations, including the American Cancer Society, have issued their own similar recommendations.

In all, they still strongly urge regular cervical cancer screening using Pap tests or similar methods for women 21 and over.

Cervical cancer deaths have been falling steadily for decades. There were about 12,200 new cases of cervical cancer and 4,210 deaths from the disease in the U.S. in 2010, according to the National Cancer Institute.

What Has Changed?

The USPSTF now recommends that women age 21 to 65 who are at average risk for cervical cancer get screened every three years for cervical cancer. That's a change from their previous recommendations.

"There's an emerging consensus among professional organizations that look at the science to say we can get by with less and do just as much good," says Michael LeFevre, MD, the co-vice-chair of the USPSTF panel issuing the guidelines. LeFevre is a professor of family and community medicine at the University of Missouri, Columbia.

Why less frequent screening? According to the task force, a Pap test every three years detects potentially dangerous cell abnormalities just as well as annual screening. But it reduces the chance of false-positive results, which can lead to unnecessary and potentially risky further testing and surgical treatment.

"I see women who've been told for so long that you must have an annual Pap. They're a little caught off guard when they hear it might not be needed as often. But most are happy," LeFevre says.

Another big change is that cervical cancer screening is no longer recommended for women and girls under 21 years of age. Previous recommendations urged women to start screening at age 21 or within three years of beginning sexual activity, whichever came first.

What About HPV Screening?

Infection with HPV, or the human papillomavirus, is known to be associated with later development of cervical cancer. It's sexually transmitted, and as many as 50% of all young sexually active women have been infected. But the task force did not recommend regular HPV screening because most scientific studies were not conclusive in finding benefit to combining the screening with regular Pap tests or performing HPV testing alone instead of Pap tests.

Instead, the task force recommended that women under 30 not get screened for HPV. They didn't offer any hard advice for women over 30, citing a lack of solid evidence.

One main reason is that while HPV is associated with later cancer, many HPV infections resolve on their own. A positive test could lead to a lot of unnecessary further testing and treatment in women who likely wouldn't develop cancer as a result of the HPV.

For women over 30, we're not recommending for or against. "We just don't have enough data," says Wanda Nicholson, MD, a member of the task force.

"We do know of ongoing clinical trials that will hopefully allow better decisions," says Nicholson, an associate professor of obstetrics and gynecology at the University of North Carolina, Chapel Hill School of Medicine. 

Existing guidelines from the American Cancer Society say HPV screening can be performed in women age 30 and older along with a Pap test every three years. But that group is updating its recommendations and organizations plan to coordinate their guidelines into a common set of recommendations by next year.

Meanwhile, ongoing trials in Europe and Canada could lead to updated recommendations on the use of HPV screening alone or along with Pap tests in women over 30 by next year.

The task force didn't address the issue of HPV vaccination, only how to screen for cervical cancer.

Who Should Get Screened?

All women 21 and older at average risk for cervical cancer should be screened every three years, the USPSTF says. The issue of whether to include HPV testing is still up to individual doctors and patients. Women over 65, and those who've had a total hysterectomy, should not be screened, the group said.

But experts stress that further reductions in cervical cancer incidence and death depend on more women getting screened. As many as half of all women are not regularly screened for cervical cancer, and their numbers are over-represented among low-income, minority, and less-educated groups.

"We think half of all cases in the U.S. occur because women are not getting screened. Not because screening is not good enough," LeFevre says. Even though less frequent screening is being recommended, screening is still critical.