Sunday, March 18, 2012
Do You Need a Pap Test Every Year?
After a decade of evolving beliefs about Pap exams, two influential groups of medical experts advise that annual Pap tests are unnecessary and should be discouraged. Here is doctors’ advice on how often to have this life-saving test…
Many women have long viewed annual Pap smears as the Holy Grail of preventive medicine – up there with breast exams and osteoporosis screening.
The test, in which doctors scrape cells from the cervix and examine them under a microscope to look for abnormalities, is considered the best way to find changes that could lead to cervical cancer.
But this week, the U.S. Preventive Services Task Force and a consortium led by the American Cancer Society published new guidelines saying that many women can wait as long as 5 years between screenings.
Women ages 30-65 may wait three years between pap exams if the results are negative, according to the guidelines. They also recommend that these women undergo “co-testing,” in which they have both the Pap smear and a test for human papillomavirus (HPV), the sexually transmitted virus responsible for genital warts.
The change was based on studies showing that more frequent Pap tests didn’t lower the risk of cervical cancer. The tests themselves are safe, but a young woman’s future fertility might be harmed from the additional procedures required from positive Pap results, which are sometimes inaccurate.
Researchers also have discovered that cervical cancer is often caused by HPV. HPV-triggered cellular changes are so slow-growing, though, that frequent testing isn’t necessary, they say.
“Most pre-cancerous lesions take 10 years to become cancer, so there’s breathing room,” says George Sawaya, M.D., professor in the UC-San Francisco Department of Obstetrics, Gynecology and Reproductive Sciences. “There are many opportunities to find and treat it before it becomes [dangerous].”
Should you follow the recommendation?
The new guidelines follow revised mammogram guidelines that increased the interval between breast cancer screenings from one to two years for some women.
The reaction among some women to revised Pap and mammogram guidelines has been unexpectedly swift and loud: We won’t give up annual screenings. Why toss the dice on our health?
“I would feel anxious waiting two or three years for a Pap test,” says Lindsay Zachary, a 29-year-old clinical social worker in Los Angeles who still asks her doctor for annual exams.
Many doctors say they continue to recommend annual testing for a 35-year-old, even if she’d previously had normal Pap and HPV tests, according to a 2010 study by the Centers for Disease Control and Prevention.
Even physicians who agree with the guidelines are in a tough position. They have to weigh a scientifically backed conclusion – that frequent screening may carry greater risks than rewards – against a deeply ingrained belief among patients that screening and early detection are vital for good health.
What’s more, less-frequent Pap testing could have a bigger impact on general health, doctors say. Gynecologists often serve as primary-care physicians, also overseeing women’s overall medical care during annual exams.
“It’s a tricky situation,” says Mario Leitao, M.D., a gynecologic surgeon at Memorial Sloan-Kettering Cancer Center in New York. “If we say, ‘Don’t have the Pap test every year,’ we’re afraid patients won’t come in annually for other exams.”
Here’s what you need to know to protect your own health:
Why the Pap Test Is Important
The Pap smear is named after George Papanicolaou, a Greek doctor who reported in 1943 that the test could provide crucial early detection of cervical and uterine cancer. Since 1955, when Pap exams became routine, cervical cancer deaths have plunged 75%.
About 55 million Paps are done annually in the U.S. About 3.5 million, or 6%, are abnormal and require follow-up, according to the National Cancer Institute (NCI).
About 12,200 cases of cervical cancer were reported in the U.S. in 2010; 4,210 women died of the disease, according to the American Cancer Society.
Significantly, about 50% of women who develop cervical cancer have never had a Pap test, says David Soper, M.D., director of the Division of Gynecology and General Obstetrics at Medical University of South Carolina in Charleston.
Women most at risk are those who wait more than three years between tests – or who never get them at all, clinicians say.
“About 90% of cases could be prevented if women get a Pap test and the interpretation is correct,” he adds.
Still, 11% of U.S. women report that they don’t have Pap screenings at all, according to the National Cervical Cancer Coalition. That’s because some don’t know about the test or don’t have easy access to medical care, Soper says.
Why the Guidelines Changed
For decades, women have had it drummed into their heads that yearly Pap tests are a must.
Yet many doctors say the research doesn’t support the benefits of such frequent screening.
“[The benefits of] annual Pap smears were never scientifically proven,” Leitao says. “They [were done annually] because women saw doctors every year.”
An analysis of 1.2 million screening results from a national early-cancer detection program found no adverse consequences from extending the interval from one to three years, according to a 2003 study led by UCSF’s Sawaya.
The reward of annual testing compared to testing every three years is diagnosing just three more cases of cervical cancer among 100,000, the study found.
“We’re not preventing more cancer by doing Pap tests annually, so why do them” and possibly cause harm? Leitao says.
The Trouble with Overtesting
Pap tests are the “poster child” for cancer prevention and early detection, but “that doesn’t mean we should overuse them,” Sawaya says.
One problem is that Pap tests sometimes provide incorrect positive results, possibly because of inflammation or vaginal infection, according to the National Cancer Institute.
“Millions of false positives lead to additional tests,” Leitao says. “That’s a lot of unnecessary procedures.”
Teenage girls and women under 21 are especially prone to cervical abnormalities that seem precancerous, according to studies by the American Cancer Society, the American College of Obstetricians and Gynecologists and other groups. About 90% of these cases resolve on their own, because young people’s immune systems are strong enough to fight off HPV before it causes cancer.
What’s more, only one to two cases of cancer occur per 1 million in girls ages 15-19. That’s why many medical experts believe that adolescents should wait until they’re 21 for their first Pap screening.
And while HPV infections are responsible for 70% of all cervical cancers, they tend to grow so slowly that two- or three-year intervals between exams pose no risk to most women’s health. (Some uncommon strains are more aggressive, requiring more immediate attention.)
The "Abnormal" Diagnosis
Most abnormal cells clear on their own, so doctors typically recommend waiting six months before deciding to remove them.
But because the words “abnormal cells” spark fear, many women often ask to have them removed right away – even though the procedures may sometimes injure the cervix, potentially hindering conception.
First, the doctor may perform a colposcopy, a non-invasive procedure in which an electronic microscope is placed near the vagina. The test allows a gynecologist to look for white areas on the cervix, which indicate abnormalities.
Next, the doctor may do a biopsy, a possibly painful procedure in which cervical cells are removed and sent to a laboratory for evaluation.
Both procedures – although life-saving in certain cases – cause problems for some women later, including premature childbirth. They also may put women at higher risk for Cesarean sections.
What You Should Do
Although many physicians support the groups' new guidelines, plenty of women are confused about or doubt them.
“The frightening thing about cervical cancer and HPV is that most women don’t have symptoms,” says Zachary, the 29-year-old patient. “The only barometer for knowing how healthy I am gynecologically is getting yearly or semi-annual check-ups.”
Lack of information makes her more anxious than the possibility of negative results, she says.
Meanwhile, physicians are advising patients individually and suggesting that women discuss how often to get a Pap test with their doctors.
That doesn’t mean you should skip your annual gynecological exams, especially if you are in your 20s and 30s. You still need a clinical breast exam and must address other health issues, even if you don’t have a Pap, Soper says.
If you see a primary-care physician for non-gynecological needs – as women over 40 are more likely to do – gynecological exams can be less frequent.
“If [patients] see another physician for their breast and general care, I just fill their birth-control prescriptions over the phone at the end of the year and tell them to check in next year,” Soper says.
Annual gynecological checkups are especially important if you’re sexually active, because of chlamydia, the most commonly reported infectious disease in the U.S., according to the Centers for Disease Control and Prevention.
This bacterial infection can cause fallopian tube infection without symptoms, and can potentially lead to infertility or a potentially life-threatening ectopic (tubal) pregnancy.
“My decision about how often women should come to my office is age- and behavior-based,” Soper says. “Sexually active women may not need a Pap test, but I want to test her yearly for STDs.”
Meanwhile, it may take years before the confusion over the new Pap smear guidelines dies down, Leitao says.
“It’s very hard to change [how things are done],” he says. “Often, when groundbreaking studies come out, it takes time to disseminate the information and for doctors to practice it.”
For more information, visit our Cervical Cancer Health Center.
Women’s Health: How Much Do You Know?
As a woman, your health concerns are as unique as your body. How you take care of yourself has a huge impact on your future, affecting everything from your ability to have children to your risk of heart disease. There's no substitute for good health, and when it's gone, it's often gone for good.
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