ROANOKE TIMES
Copyright (c) 1996, Roanoke Times
DATE: Tuesday, November 12, 1996 TAG: 9611120059
SECTION: EXTRA PAGE: 3 EDITION: METRO
COLUMN: PERSONAL HEALTH
SOURCE: JANE BRODY
Lawsuits over two eventually fatal cases of cervical cancer that were missed in repeated misreadings of Pap smears and news reports of substandard methods in some laboratories have had at least two happy results.
The attention of women and the medical profession is now focused on the true benefits and limitations of this most popular screening tool. And new rules have been established and techniques designed to improve the test's accuracy.
One technique, Papnet, uses a computer to search for abnormalities in smears deemed ``normal'' by laboratory technicians. Its manufacturer, Neuromedical Systems Inc., has raised professional hackles with aggressive advertising urging women to pay the $40 themselves if their insurance companies refuse to cover the extra cost.
Even with past shortcomings, the Pap smear has been an immeasurably valuable test. Since it was pioneered more than 50 years ago by Dr. George Papanicolaou, it has helped save more lives than any other cancer test and has been a major factor in a 70 percent decline in deaths from cervical cancer, once the leading cancer killer of women and now only the tenth leading killer. Of the nearly 5,000 American women who die from cervical cancer each year, 80 percent have not had a Pap test in five or more years.
But in some ways, the test's success has been its own worst enemy. Millions of women think it is 100 percent accurate, which no test is or could ever be. Rather, it is 70 percent to 95 percent accurate in detecting cervical abnormalities, and sometimes - less than 1 percent of the time - a cancer is missed.
Studies have shown that the main source of error lies not with the technician who reads the slide, but with the health professional - usually a doctor - who does the smear.
And because the American Cancer Society suggested in 1980 that some women may not need an annual Pap test, many now assume incorrectly that if their last few tests were negative, it is safe to skip it for the next several years.
Older women, too, are under the impression that after menopause, a regular Pap smear is no longer necessary. Not so, say most experts, including Dr. Hugh Shingleton, a gynecologist who is the society's vice president for cancer detection and treatment.
Each year 62 million women in this country have cells scraped from the cervix, or opening to the womb, which are then smeared on a slide, treated with a preservative and sent to a laboratory for analysis by a cytotechnician, who may examine 100 such slides a day.
Among 200,000 to 300,000 cells on each slide, the technician looks for cells that appear abnormal and prepares a report for the doctor, including whether the sample of cells was adequate and the slide properly prepared.
Every year about 10 percent of those reports reveal some abnormality of cervical cells. Most abnormalities are minor and are believed to have little or no long-term significance; they may disappear on their own or remain the same indefinitely. Many things besides a premalignant or cancerous condition can cause Pap smear abnormalities, among them inflammation caused by an infection and exposure to irritants.
But sometimes the abnormality appears more ominous - a kind that should prompt the doctor to examine the woman's cervix under magnification and, if a lesion is found, take a biopsy for further analysis.
Depending on the biopsy results, which may show a suspicious, premalignant or cancerous condition, treatments can range from watchful waiting to freezing or burning off the abnormal cells to hysterectomy. The test may also reveal an infection, including infection by the human papillomavirus (HPV), a sexually transmitted organism that causes genital warts. Some HPV infections can eventually lead to cervical cancer.
The cancer society's current recommendations aside, most gynecologists and the College of American Pathologists advise every woman to have an annual Pap test starting with the year she becomes sexually active or turns 18, whichever comes first. Furthermore, annual Pap tests should be done after a hysterectomy and should continue indefinitely after menopause.
As Shingleton said, ``Nearly a third of invasive cervical cancers occur in women over 60.'' Dr. Bethan Powell, a specialist in gynecological cancer at the University of California in San Francisco, noted, ``Among women over 65, one in six with an abnormal Pap will have a significant lesion or cancer.'' The comparable figure in women under 35 is one in 100, she said.
At greatest risk of developing cervical cancer are women who became sexually active at a young age, those who have had numerous sexual partners or whose partners did, those who have had a sexually transmitted disease and those who have had a previous Pap test showing premalignant changes.
The timing and preparation for a Pap test can affect its quality. The best time for premenopausal women is mid-cycle - between menstrual periods - since slides contaminated by menstrual blood are hard to read. Women past menopause can have the test any time. All women should avoid sexual intercourse, douching and using vaginal products for 48 hours before the examination.
Pap smears are quick and painless, causing at most a momentary tickling sensation. During a routine pelvic examination while a woman is lying on her back with knees up and feet in stirrups, the doctor should use a spatula to scrape cells from the outer cervix and a tiny brush to scrape cells from inside the cervical canal. Studies have shown that use of a cotton swab is less effective in sampling cervical cells. The laboratory results are typically reported to the doctor within two to three weeks.
Although computerized rescreening of slides that technicians deemed normal has been approved by the Food and Drug Administration as a quality control measure, studies have yet to demonstrate that the computer analyzes Pap slides as well as or better than trained technicians, said Dr. Diane Solomon, a cytopathologist at the National Cancer Institute.
She and other experts fear that overuse of the computerized test will produce millions of suspicious findings where no abnormalities exist. They are also concerned that such ``false positive'' results would drive up the cost and inconvenience of Pap tests enormously.
Dr. Rebecca Johnson, head of pathology and clinical laboratories at Berkshire Medical Center in Pittsfield, Mass., said the best quality control was to have an annual Pap test, ``because regular repetition compounds the test's sensitivity.''
``If an abnormality is missed one year, it is very likely to be picked up the next year,'' Johnson said.
``This is the most effective way to detect cervical cancer, which nearly always develops over a period of years,'' she said, noting that it was preceded by a series of curable premalignant changes.
For more information
The College of American Pathologists has produced a brochure, ``Pap Examination: It Can Save Your Life,'' which is distributed free and can help consumers assess the quality of the laboratory that evaluates their tests. A copy can be obtained by calling (800) 522-5678.
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