October 17, 2011 — Screening for cervical cancer is equally effective with conventional Pap testing and liquid-based cytology with human papillomavirus (HPV) testing. So concludes the upcoming update of the 2003 US Preventive Services Task Force (USPSTF) recommendations, based in part on 2 literature reviews published online October 17 in the Annals of Internal Medicine. In addition to concluding that liquid-based cytology HPV testing is generally not superior to conventional Pap tests, the reviewers conclude that routine cervical cancer screening is generally not needed in women younger than 20 years and older than 65 years.
Evelyn P. Whitlock, MD, MPH, lead author of the first study, told Medscape Medical News that "cervical cancer screening using conventional cytology (Pap test) or liquid-based cytology would be expected to be equally effective. And, although 1-time testing comparisons show that HPV is more sensitive but less specific for precancerous lesions than cytology, trials comparing HPV-enhanced strategies with cytology have not shown a clear advantage after repeat screening, nor have they compared the impact on false-positive-related burden or harms."
Dr. Whitlock, from the Oregon Evidence-Based Practice at Kaiser Permanente Northwest in Portland, also noted that HPV trials currently available are European and do not compare with current American practice for the management of abnormal screening results.
The review consisted of 4 fair- to good-quality studies, with a total of 141,566 participants, and compared the evidence on liquid-based cytology and high-risk HPV screening with conventional cytology in population-based screening for cervical cancer.
Dr. Whitlock said that "although this review pointed out the need for more complete information on the potential harms and benefits of adding on or substituting HPV testing for cytology, we also found that the research about HPV and cervical cancer is very active and is moving in some very interesting directions. In the future, this research may support using more specific types of HPV testing, along with cytology, screening history, and other information, to individualize screening recommendations, improve screening performance, and safely reduce screening intervals for many low-risk women. At the same time, the emergence of a young cohort of HPV-vaccinated women eligible for cervical cancer screening will raise new, important questions about appropriate approaches."
The second review focused on the ages at which to appropriately begin and end cervical cancer screening. Lead author Kimberly K. Vesco, MD, MPH, and colleagues presented a "narrative review" of risk factors and other epidemiologic considerations.
Dr. Vesco, who is from the Center for Health Research at Kaiser Permanente Northwest, told Medscape Medical News that "the evidence suggests that the potential harms of screening outweigh the benefit of cervical cancer screening for women under 20." Current methods have higher false-positive rates in younger women, because the methods used to diagnosis and treat cervical intraepithelial neoplasia (CIN) have potential adverse effects, and because HPV infections and cytologic abnormalities have relatively high rates of regression in young women, she said.
Dr. Vesco said that the data support discontinuing screening for women 65 years and older without a history of CIN or cervical cancer who have had recent negative cervical cancer screening.
"The evidence to define adequate prior screening is limited, but the American Cancer Society defines it as 3 or more documented consecutive negative screening tests and no abnormal/positive cytology tests within the last 10 years," Dr. Vesco said.
Dr. Whitlock warned against discontinuing cervical cancer screening for older women who do not fit these guidelines, however.
"A 65-year-old women who has not been screened regularly or who has a history of abnormal Pap tests, CIN, or cervical cancer would be a candidate for continued screening. Before discontinuing screening, all women should speak with their clinician, particularly women known to be at increased risk due to a weakened immune system (like those with HIV) and women who were exposed to diethylstilbestrol in utero. Women of any age with vaginal bleeding, pain, or other symptoms related to possible cervical cancer should always seek prompt medical attention, regardless of screening history," Dr. Whitlock said.
The new draft recommendations on starting and stopping screening, type of test, and intervals will be available for public comment on October 19 on the USPSTF Web site.
Dr. Vesco and Dr. Whitlock have disclosed no relevant financial relationships.
Ann Intern Med. Published online October 17, 2011. Abstract
Medscape Medical News © 2011 WebMD, LLC
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Cite this: New Guidelines to Urge Pap Tests Only for Women 20 to 65 - Medscape - Oct 17, 2011.