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.