While confusion surrounds breast-cancer screening, existing data point heavily in favor of later initiation of Pap testing and expanded inter-test intervals for women with normal Pap histories.
The remarkable 50% reduction in cervical cancer rates over the past 30 years, combined with emerging understanding of the virology and epidemiology of human papillomavirus (HPV), has facilitated an increasingly informed, evidence-based approach to cervical cancer screening.
The annual Pap smear was once considered a critical component of women’s health care, but the past decade has seen a relaxation of that standard, as well as the introduction of other tests to predict a woman’s cancer risk.
HPV testing is now routinely employed to determine plans for women with atypical squamous cells of undetermined significance Pap results. It is used along with cytology to determine appropriate Pap screening schedules for women aged 30 years and older.
Citing a low rate of cervical cancer among younger women, ACOG now recommends that women begin Pap screening at age 21 years. Previous guidelines called for the first Pap test to be done three years after the onset of sexual activity or at age 21 years, whichever occurred sooner.
Although many sexually active young women show evidence of HPV infection, most will clear the virus to undetectable levels within one to two years. Studies show that fewer than 6% of women aged 12 to 18 years have Pap results showing low-grade squamous intraepithelial lesions (LSILs), and fewer than 1% have high-grade squamous intraepithelial lesions.20 Of those with LSIL, 91% regress to normal within three years.
Those findings had already persuaded ACOG and the American Society for Colposcopy and Cervical Pathology to recommend a conservative approach to the management of cervical dysplasia in adolescents, generally calling for repeat Pap tests rather than immediate intervention.
As ACOG’s practice bulletin states, “Delaying the onset of screening until age 21 years is a logical incremental step in practice guidelines, consistent with this conservative approach to management of adolescents with cervical test result abnormalities.”2
The main motivation for delaying screening of adolescents is to avoid unnecessary treatment. Excisional procedures for the treatment of cervical dysplasia can predispose women to preterm labor later in life, raising the risk of low birth weight, developmental problems, and respiratory difficulty in the neonate.
For women aged 21 to 29 years, ACOG now recommends a Pap test every two years rather than annually. At age 30, HPV DNA testing and cytology are recommended. If both tests are negative, the screening interval can be widened to every three years. (With positive HPV DNA, even in the presence of negative cytology, colposcopy is indicated. Abnormal cytology is managed according to normal protocols.) Per the new guidelines, 30-year-old women who have had three consecutive normal Pap tests, even in the absence of HPV testing, can extend the Pap interval to three years.
In a more recent development, USPSTF released draft recommendations this week proposing to change it’s guidelines to recommend three year intervals for all women aged younger than 65. The draft is open to public comment until Nov. 16, 2011.
Women at heightened risk of cervical cancer should continue to undergo annual screening. This includes women with HIV, who should have Pap testing every six months during the first year after diagnosis, followed by annual screening; immune-suppressed women, including those taking medications after transplant surgery; women exposed to DES in utero; and women with a history of cervical intraepithelial neoplasia (CIN)-2, CIN-3 or cervical cancer.
Because most women are exposed to HPV shortly after the onset of sexual activity, the presence of the virus in older women generally represents persistent rather than new infection. ACOG recommends that women cease regular Pap screening once they reach 65 to 70 years of age.
However, older women with multiple sexual partners, while at lower risk for CIN than younger women, should still be screened routinely. Also, women with a history of abnormal cytology should not discontinue screening entirely until 10 years after the last abnormal result, but the interval between tests can be widened to every three years after three consecutive normal tests. Women with a history of CIN-2 or higher remain at risk of recurrence for 20 years following treatment, during which time they should undergo annual screening.
Despite ACOG’s dismissal of the annual Pap smear as “tradition,” the convention of an annual well-woman visit remains important for many women. This is especially true for the as many as one-third of women who seek primary care in a women’s health setting.21
The annual exam serves as an opportunity to screen women for sexually transmitted infections22 and other gynecologic conditions and address family planning and such preventive health topics as smoking, substance use, exercise and nutrition. Screening for physical and mental health problems is also an important component of the annual visit, as is assessing a woman’s safety at home and in the workplace.
As we navigate the data regarding women’s health screening tests, we must continually remember to take the complete patient into account. Many women perceive breast cancer to be their primary health risk and may accordingly miscalculate their risk for such conditions as heart disease and lung cancer, which are, respectively, more common and more deadly.23
As we rethink guidelines for cancer screening, we must also be diligent in reminding women about other preventive health themes that might not be splashed daily across their newspapers — smoking cessation, mainting healthy weight, stress reduction and regular exercise.
In addition to lowering risks of some reproductive cancers, these behaviors will reduce a woman’s risk for chronic illnesses. Colonoscopy, fecal occult blood testing, cholesterol testing, blood glucose testing and other patient-specific screening tests should not fall by the wayside as we deal with breast and cervical cancer guidelines.
Health-care access should also remain a primary concern. Half the women diagnosed each year with cervical cancer had never had prior screening. In addition to advising our current patients about their health risks and conducting appropriate testing, we must remain mindful of those who lack care and facilitate their access to timely preventive services. Our patients and the public look to us to safeguard their overall health and to maintain perspective amid a flurry of evidence and opinions.
Lisa Stern, MSN, APRN, is the Research Manager of Planned Parenthood Federation of America.
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This document was last updated Oct. 25, 2011.