Federal health advisors say women can now consider three options when it's time for their cervical cancer screening tests. The influential group, the U.S. Preventive Services Task Force (USPSTF), has expanded its recommendations for this potentially life-saving exam.
The new recommendations are published in the latest issue of JAMA.
Pap smears have saved many lives since they became available decades ago. Inspecting samples of cervical tissue for pre-cancerous changes is effective at catching possible cancer, and is still the go-to test for women aged 21 to 29, according to the USPSTF guidelines.
But there's another option. "Most cervical cancer is caused by what's called the human papilloma virus, or HPV," says Dr. Douglas Owens, a professor of medicine at Stanford University and vice-chair of the USPSTF. "And we now have tests for HPV and that's an important step forward."
These tests are available alone or in combination with the Pap test. And the USPSTF now says the evidence is strong enough that HPV tests can be used by themselves, for women over 30. That third choice expands on the task force's previous recommendation, which was for the Pap test or the combination test.
And while Pap tests should be repeated every three years, women can wait five years between HPV tests.
"Five years is a good balance between the benefits and harms," Owens says. "It's still highly effective at detecting cancer, and screening more frequently than that may increase some of the potential harms, so we think that's a good interval."
Potential harms of too frequent screening include unnecessary follow-ups such as biopsies. In a draft recommendation released last year, the task force had considered suggesting just two options, either the Pap smear or the HPV test, but its final recommendation included the hybrid test too.
"The HPV test alone is not available everywhere," Owens explains, "And so we want to be sure that women no matter where they're receiving care have options for cervical cancer screening."
He says the combination test is widely available, as is the Pap test, "so all of those are good options and a woman can discuss with her physician what's available at the place where she's receiving care."
Women may not notice the difference between tests because tissue samples are all collected the same way. But Debbie Saslow, senior director for HPV-related and women's cancers at the American Cancer Society, says if women have a choice, she'd recommend the HPV test for women over 30.
"I truly believe that including the HPV test, either along with the Pap or instead of the Pap, is superior than the Pap alone," she says. There's some evidence the HPV test is better than the Pap test at detecting a less common form of cervical cancer, adenocarcinoma, she says. "So wouldn't you rather find the two most common cancers instead of just the one most common type?"
The task force emphasizes that all three tests are highly effective. The overarching recommendation is simply that women should get screened, and to do so regularly until the age of 65. If screening has been adequate up to that point, the task force says women do not need further cervical cancer screening.
Health officials also recommend the HPV vaccine, which is given to girls and young women, up to age 26. But Owens says a vaccine alone doesn't replace cervical cancer screening.
"Our recommendation applies to everyone whether you've been vaccinated or not," he says. "It's very important that women do not forego screening because they've been vaccinated."
An effective vaccine could ultimately render cervical cancer screening unncesscary, but that change will require careful study and could be years away.
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