ROCKVILLE, MarylandPhysicians can discontinue cervical cancer screening for many women age 65 and older, and delay screening for some young women until age 21, according to new guidelines developed by the US Preventive Services Task Force (USPSTF).
The group strongly endorsed regular screening for women ages 21 to 65, but said existing studies did not provide evidence that annual screenings achieve better outcomes than screenings performed every 3 years. However, it recommended that women have at least two normal annual screenings before moving to a schedule of testing every 3 years.
The panel noted that its cervical cancer screening recommendations are largely consistent with those released by the American Cancer Society (ACS) in November 2002. The National Cancer Institute (NCI) gave its support to the USPSTF and ACS guidelines. "The key to continued reductions in deaths from cervical cancer is early detection, and these guidelines will help women and their doctors make informed choices about screening," said Peter Greenwald, MD, DrPH, director of NCI’s Division of Cancer Prevention.
Although direct evidence for setting a starting and stopping age for testing is limited, "indirect evidence suggests most of the benefit can be obtained by beginning screening within 3 years of onset of sexual activity or age 21 (whichever comes first) and screening every 3 years," the panel said. Previously, USPSTF recommended that screening begin at age 18. The ACS guidelines offer the same recommendations for starting Pap smears, but support annual screening until age 30 and every 2 to 3 years thereafter in average-risk women who have had three consecutive negative smears. The ACS suggests that screening can stop in women age 70 who have three consecutive negative exams and no abnormal exams within the prior 10-year period.
The USPSTF concluded that the harms of screening women age 65 and older with a history of normal Pap tests outweigh the benefits. It specifically cited the adverse effects of false-positive tests on patients and the dangers from invasive procedures performed after a false positive. "The yield of screening is low in previously screened women older than 65 due to the declining incidence of high-grade lesions after middle age," the panel said. Therefore, it recommended against screening such women "if they have had an adequate recent screening with normal Pap smears and are not otherwise at high risk for cervical cancer."
The panel also recommended against screening women who have had a total hysterectomy for benign disease because the yield of cytologic screening is very low after hysterectomy and "potential harms of continued screening after hysterectomy are likely to exceed benefits."
The panel found insufficient evidence to recommend for or against the routine use of new screening technologies such as liquid-based cytology, computerized rescreening, and algorithm-based screening. The "evidence to determine both sensitivity and specificity of new screening technologies is limited," the panel said. Available evidence suggests that the new techniques are slightly more sensitive than conventional Pap smears but are more likely to yield false-positive exams.