Currently, many of the estimated 2.5 million American women a year with abnormal but inconclusive results are given at least two follow-up Pap tests within a year; or a colposcopy test, in which the cervix is examined and sometimes biopsied; or a test for the human papillomavirus, or HPV, the chief cause of cervical cancer.
The new guidelines say HPV testing alone should be the preferred method for many women because it is more convenient for the patient. In many cases, the HPV test can be done from the Pap test sample.
If the HPV test is negative for the riskiest forms of the virus - as is the case in about half of these women - the patient can be virtually assured she does not have cancer and does not need more follow-up testing, the experts said.
By some estimates, that could save hundreds of millions of dollars a year in health care costs.
The guidelines were created at a conference last year sponsored by the American Society for Colposcopy and Cervical Pathology. Participants included representatives from 29 professional groups, including the American Cancer Society and the American College of Obstetricians and Gynecologists.
"It should set a standard for how women with abnormal screening tests should be handled," said a co-author of the guidelines, Dr. L. Stewart Massad of Chicago's Cook County Hospital.
The guidelines appear in Wednesday's Journal of the American Medical Association.
They reflect doctors' better understanding in recent years of HPV and how a few high-risk strains of the virus are the primary cause of cervical cancer.
"Right now, there's a lot of overdiagnosis, a lot of extra unneeded follow-up tests that are being done, which are a tremendous health care cost but also a tremendous cost to the women in terms of anxiety, time and discomfort," said the cancer society's Debbie Saslow. If many women with inconclusive results can be reassured, "that will be a big benefit for society."
Pap tests plus an office visit may cost roughly $40, compared with about $100 for an HPV test, Saslow said, while colposcopy can cost $300 or more.
An estimated 50 million U.S. women a year undergo a Pap test, in which cells are scraped from the cervix and examined under the microscope for abnormalities that could mean cancer.
When a Pap test comes back abnormal, "every patient that I see, the first thing they think is, 'Do I have cancer and am I going to die?'" said Dr. Thomas Wright, a Columbia University pathologist and lead author of the guidelines.
Until now, there has been no consensus among doctors on which follow-up test is best. The new guidelines say that all three methods are safe and effective but that HPV testing is preferred if Pap tests are done with liquid-based screening, which is becoming increasingly popular at labs around the country.
With this technique, cells scraped from the cervix are collected in liquid instead of being smeared between two slides. Liquid-based screening means more cells are available for HPV testing, according to Wright, who is on the speakers' bureau for companies that make liquid-based test kits.
Daira Rivera, a 24-year-old mother of two from New York City who had a repeat Pap test three months after an abnormal result last year, said the new guidelines probably would have meant a quicker diagnosis.
"I would not have gone through the stress of whether or not I do have cancer. I would not have had those nightmares at night, the cold sweats and every time I looked at my kids wondering what would their life be like without me," she said.
After the follow-up also was abnormal, a colposcopy showed her chances of getting cancer were slim.
"It's like more than a ton was lifted off my shoulders," Rivera said.
The guidelines conference was held in conjunction with a workshop convened by the National Cancer Institute to update the terminology for labs reporting Pap test results. The terminology was last updated in 1991, before liquid-based testing was developed and before doctors clearly understood the role HPV in cervical cancer.
"It's going to improve care of women because we have this integration of common terminology with uniform management guidelines, both of which are based on our most current knowledge," said the NCI's Dr. Diane Solomon.