Screening women for cervical cancer every single year may do more harm than good.
For fifty years an annual Pap smear has been the gold standard of screening for cervical cancer in women. Now a federal advisory group and the nation's leading cancer organization have changed their tune. They no longer recommend that women have a Pap test each year.
The recommendations do not apply to women who are at very high risk for cancer, such as those who have been diagnosed with a high-grade precancerous cervical lesion or who have weakened immune systems.
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The US Preventive Services Task Force, (USPSTF) a panel of independent experts convened by the government, and the American Cancer Society (ACS) have each released new guidelines for cervical cancer screening that recommend against routine yearly testing. Instead, the guidelines recommend testing every 3 years for women aged 21 to 65.
For women aged 30 to 65, the new guidelines recommend screening every 5 years with both a Pap smear and a test for the human papillomavirus (HPV). That recommendation is based on data showing that less frequent screening with both tests provides a comparable benefit in cancer detection to more frequent Pap testing alone. Routine screening of women younger than 21 and older than 65 is not advised under the new guidelines.
Pap testing has been responsible for a dramatic reduction in cervical cancer deaths.
The updated recommendations apply to women, regardless of sexual history, who have a cervix and show no signs or symptoms of cervical cancer. The recommendations do not apply to women who are at very high risk for cancer, such as those who have been diagnosed with a high-grade precancerous cervical lesion or who have weakened immune systems.
Both the USPSTF and ACS emphasize that Pap screening continues to be a important diagnostic tool. Since its widespread introduction, Pap testing has been responsible for a dramatic reduction in cervical cancer deaths in the United States. Among current cervical cancer deaths, most occur in women who have never been screened or who have not been screened in the last 5 years.
According to Dr. Wanda Nicholson, an ob/gyn at the University of North Carolina and a member of the USPTS, bringing those groups of women into the screening process remains an important public health objective.
Why Test Less Frequently?
The groups based their updated recommendations on research demonstrating that Pap testing every year provides little or no benefit compared to testing every 3 years, but that more frequent testing carries potential harm. False positives -- that is, a test indicates the existence of disease when in fact none is present -- are very common and often lead to invasive testing that can produce long-term complications, including difficulties with pregnancy and delivery.
Pap testing every year provides little or no benefit compared to testing every 3 years, but that more frequent testing carries potential harm.
Debbie Saslow, ACS's director of breast and gynecologic cancer, sums it up this way: "We now know that annual screening causes more harm than good because it leads to many extra invasive procedures without increasing the number of cancers detected."
A New Attitude Toward Screening
The new Pap guidelines reflect a shift in medical thinking about the advisability of frequent and routine disease screening in the general population. Recommendations advocating more limited screening for both breast and prostate cancer have also been issued within the past several years.