New Guidelines for Evaluating Women with Abnormal Pap Test Results (dateline November 4, 2002)
New guidelines for investigating abnormal Pap test results were recently established by a panel of 121 experts from 29 professional organizations, federal agencies, and national and international health organizations in a conference sponsored by the American Society for Colposcopy and Cervical Pathology (ASCCP). The new recommendations are based on formal literature reviews of medical articles published between 1988 and 2001 and input from the professional medical community. According to ASCCP, the guidelines are meant to reduce time, and therefore patient stress, involved with interpreting abnormal Pap test results.
A Pap test (also called a Pap smear) is a screening procedure used to examine cells from the cervix and the vagina. Cervical and vaginal cells are studied to determine whether there is evidence of cancer or pre-cancerous changes. If abnormal cells are found, they are classified according to their degree of abnormality. An estimated 50 million Pap tests are performed each year in the United States, and 3.5 million of those tests produce abnormal results. Most abnormal Pap tests are caused by cervical infections or inflammation which can usually be successfully treated before they lead to cancer.
"It is expected that the Consensus Guidelines will become widely adopted in the United States and aid in the standardization of care of women with all types of abnormal Pap tests," said lead author Thomas C. Wright, Jr. MD, Associate Professor of Pathology at Columbia University College of Physicians and Surgeons, as quoted in an ASCCP news release. Edward J. Wilkinson, MD, Chairman of the ASCCP Consensus Guidelines Conference, called the guidelines "the most comprehensive recommendations ever published for women with abnormal Pap tests."
According to the ASCCP, the guidelines make use of new cancer screening technology, namely the new liquid-based Pap test (e.g., "ThinPrep"), which involves collecting cervical cells in liquid rather than smearing them between two slides. If a woman undergo a liquid Pap test that reveals a common abnormal result called ASC-US (atypical squamous cells of undetermined significance), an HPV test may be performed instead of the usual protocol: repeat Pap tests over the next 12 months or immediate colposcopy--two options that are still valid but less convenient. (See colposcopy explanation below).
Because the majority of cervical cancers result from a few strains of the sexually transmitted human papillomavirus (HPV), testing for HPV is a simple, quick way to determine whether a woman with ASC-US Pap results needs further evaluation. If a woman's HPV test is negative, then the chances of cervical cancer are remote, and the woman can usually return to normal screening with Pap tests. On the other hand, a positive HPV test identifies women who need further evaluation. (HPV testing can usually be performed on the sample cell sample obtained during the original Pap test).
While the panel found HPV to be effective for women with less serious ASC-US Pap test results, they said that HPV testing should not have a role in evaluating more serious abnormal Pap results. Instead, women with LSIL (low-grade squamous intraepithelial lesion) or HSIL (high-grade squamous intraepithelial lesion) Pap results should undergo immediate colposcopy. A colposcopy involves viewing the cervix through a special magnifying lens (called a colposcope) to check for abnormalities. A colposcopy may involve removing cervical tissue samples for analysis. If the colposcopy results reveal substantial pre-cancerous cells or cancer, additional cervical tissue must be biopsied to further evaluate the situation.
The new guidelines come shortly after the National Cancer Institute announced a major update to the system used to classify Pap test results (the 2001 Bethesda System, --ADD LINK) . Experts say the new guidelines for abnormal Pap test results will reduce the time it takes to evaluate women, decrease the chances of over-diagnosis, help prevent unnecessary additional testing (which may reduce healthcare costs), and provide sooner peace-of-mind for the majority of women whose abnormal Pap results are no cause for concern.