Major national medical groups have finally reached agreement on how often women should have a Pap test to detect cervical cancer, but their new guidelines aren't likely to end the longstanding debate about whether women should have annual Pap smears.
The new recommendations, issued today in Washington, advise an annual Pap test and pelvic examination beginning when women become sexually active or reach age 18. After three or more consecutive normal tests, the Pap test may be performed less often, at the discretion of the woman's physician.
Agreeing on those guidelines are the American Cancer Society, the American College of Obstetricians and Gynecologists, the American Medical Assn., the National Cancer Institute and other organizations.
The consensus represents a "meeting of the minds" on Pap-test intervals, said Joann Schellenbach, spokeswoman for the American Cancer Society, which previously recommended the Pap test be done every three years after two initial normal tests.
But despite the organization's consensus, four Los Angeles-area gynecologists polled by The Times said they will continue to recommend Pap tests annually--or in some cases even more frequently--for most women to reduce cervical cancer and other conditions. This year, the cancer society expects 13,000 new cases of cervical cancer to be diagnosed.
Dr. Reinhold Ullrich, a Torrance gynecologist, clinical assistant professor of obstetrics and gynecology at UCLA School of Medicine and president-elect of the Los Angeles County Medical Assn., said he recommends Pap smears once a year for sexually active woman to age 40, then once every six to nine months.
Defending the guidelines, Dr. Robert V. P. Hutter, a pathologist in Livingston, N.J., and former national president and current chairman of the American Cancer Society's National Advisory Committee on Cancer Prevention and Detection, said: "On the basis of current scientific information, the recommendations that were made are appropriate. (But) recommendations are just that. In an individual practice setting the physician and the woman can develop what they feel is best for that woman. These guidelines apply as long as no cervical abnormality is found."
Some of the Los Angeles-area doctors interviewed said the new guidelines appeared to weigh economic considerations too heavily. In a national study conducted for the American Cancer Society, the average cost of a Pap test, including the charge for an office visit, is $76.
But that's a small price, suggested Dr. W. Benson Harer, a San Bernardino gynecologist and district chairman for the American College of Obstetricians and Gynecologists, who pointed to two studies in the February, 1987, issue of the journal Obstetrics & Gynecology.
One study found that one-third of the patients with human papillomavirus (HPV) infection--sometimes detectable by the Pap test--can be expected to develop cervical intraepithelial neoplasia, a potentially cancerous lesion detected by Pap tests, within a year.
In the second study, 37% of women with cervical cancer had a normal negative Pap test within three years of their diagnosis.
Range of False Negatives
In recent months, the Pap test has come under increasing scrutiny after it was reported that the false negative rate ranges from 20%-40%. That figure is based on studies done before 1979, said Mort Lebow of the American College of Obstetricians and Gynecologists, who added that no recent studies of false negative rates have been done.
Lebow and others agree that the false negative rate for Pap tests can range from 5% to 70%, depending on the skills of the cytotechnologists, the physicians who obtain the samples and the pathologists who evaluate them.
Part of the accuracy problem in the Pap test, developed nearly 60 years ago by Dr. George N. Papanicolaou, is inherent, experts say, because it is a subjective evaluation. A physician scrapes cells from the cervix and smears them on a slide, which is then specially stained and examined under a microscope.
Cytotechnologists examine the slide, looking for any evidence of abnormal cells. Abnormal slides are then referred to pathologists for further evaluation.
Examination of cervical cells by the Pap test can sometimes detect, in addition to cervical cancer and precancerous conditions, infections and sexually transmitted diseases such as chlamydia, herpes and HPV. The latter, say physicians, may be associated with cervical cancer.
"This test is one of pure judgment," said Elsie Carruthers, secretary-treasurer of the Cypress-based American Society for Cytotechnology. "There are a lot of factors in reading Pap smears, (and) the best lab can read only what's on that slide."
Overworked cytotechnologists also contribute to the accuracy problem, experts say. Under California's Department of Health Services guidelines, cytotechnologists cannot be required to examine more than 75 one-slide gynecologic cases or 50 two-slide cases a day, said a spokesman.
"Some cytotechnologists are reading more than 50 to 75 slides a day," said Carruthers, explaining that many of them operate as independent contractors, working for more than one laboratory and often receiving $1 or less per slide.
Despite the fallibility of Pap tests, women can improve accuracy, experts agreed.
Questioning the doctor is one way, said Schellenbach of the American Cancer Society. "Ask the doctor, 'Where do my slides go--out of state or nearby?' 'Is it a reputable lab?' Obviously, slides traveling a great distance could be mishandled."
Timing Is Important
Timing of the test is important, said Carruthers. "The best time of the month to have a Pap is between the 12th and 16th day of the menstrual cycle," she said, explaining that women should count the first day of bleeding as Day 1.
Carruthers also suggests avoiding intercourse for 24 hours before the test and the use of contraceptive jellies, foams, douches and vaginal medications for 72 hours before the test.
If a Pap test is abnormal, March said, the next step should be colposcopy, "an examination of the cervix with minimal magnification," to look for patterns of cells.