Each year, approximately 3.5 million women in the United States have an abnormal Pap test that requires some form of further evaluation or treatment.
Now, under the leadership of a Columbia pathologist, new national consensus guidelines have been written to help clinicians better evaluate women whose Pap tests suggest they may have cervical cancer or abnormal cells that may lead to cervical cancer. The recommendations were published in the April 24 Journal of the American Medical Association.
"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," says Dr. Thomas C. Wright, lead author of the consensus guidelines, associate professor of pathology at P&S, and associate attending in pathology at New York-Presbyterian Hospital.
The guidelines describe how best to utilize new technologies including liquid-based cytology, in which the physicians place a scraping of cervical cells in a solution for analysis rather than on a microscope slide in the traditional Pap test, and DNA testing for human papillomavirus (HPV), a sexually transmitted virus that is the primary cause of cervical cancer.
Scientists have identified approximately 100 strains of HPV, 25 of which cause disease in the female genital tract. Thirteen of the 25 are associated with a high risk of cancer.
"Currently women with abnormal Pap results are treated differently throughout the country," Dr. Wright says. "This is for a variety of reasons including different training, different patient mixes, and different access to new technology. Also, technology has changed within the past five years with the introduction of liquid cytology and HPV testing. The guidelines hope to formalize the diagnostic work-up for women with abnormal Pap results."
The Food and Drug Administration in 1997 approved liquid cervical cytology, but the method only reached widespread use in 1999. Today, approximately 60 percent of physicians nationwide use liquid cytology.
One of the important recommendations in the guidelines addresses women with the most common type of abnormal Pap test, an inconclusive result referred to as ASC-US, or atypical squamous cells of undetermined significance. Before these guidelines, women with ASC-US would usually get either several repeat Pap tests or undergo a colposcopy, during which the cervix is examined using a special type of microscope and biopsies are taken.
The new guidelines say the other approaches may still be used, but HPV testing is preferred whenever liquid-based Pap tests are employed. If the liquid test is used, the laboratory can test the sample used for the original Pap test for HPV, eliminating the need for a repeat doctor visit. The test quickly reassures women who are HPV-negative they are unlikely to have cervical cancer and that they simply need regular annual Pap tests and it identifies women who are HPV-positive and need further evaluation.
For most women with more serious abnormalities on their Pap test, the guidelines recommend colposcopy and find HPV testing has no role. The colposcopy recommendation is an important change since previously many of these women were simply followed with repeat Pap tests.
The American Society for Colposcopy and Cervical Pathology (ASCCP) sponsored the guidelines and worked with representatives from 29 national organizations and federal agencies involved in women's health care. These experts evaluated medical literature from the past decade and used the results of the $25 million National Cancer Institute's ongoing clinical trial of more than 5,000 women with abnormal Pap tests to develop the guidelines.
Dr. J. Thomas Cox, a co-author and ASCCP committee chairman for the guidelines, says, "We're excited that the consensus guidelines have incorporated the new technologies and define for the practicing clinician both when to and when not to use them."
Dr. Edward J. Wilkinson, chairman of the ASCCP Consensus Guidelines Conference, says, "These are the most comprehensive recommendations ever published for women with abnormal Pap tests."
In an upcoming article in JAMA, Dr. Wright and colleagues from Harvard have evaluated the economics and clinical outcomes of different management approaches to abnormal Pap tests. They found that using a combination of liquid-based cytology and HPV DNA testing when women have ACS-US results provides the same or greater life expectancy benefits and is more cost-effective than other approaches.
JAMA has made the 2001 Consensus Guidelines available for free to both clinicians and patients at http://www.ama-assn.org.