WOMEN : PAP SMEARS SAVE WOMEN'S LIVES.

Byline: Marie McCullough Knight-Ridder Tribune News Wire

Half a century ago, a safe, inexpensive screening test was developed that could have put a virtual end to the leading cancer killer of women.

The problem is, many women didn't get the test - and many still don't.

The Papanicolaou smear - better known as the Pap test - was a breakthrough in fighting cervical cancer, then the top cause of cancer deaths among American women, and still the top cancer killer worldwide. The test detects not only cancerous cervical cells, but abnormal cells that, if left untreated, often become cancerous.

Early detection with the Pap test has dramatically reduced the threat of cervical cancer. National records show that incidence and mortality rates have fallen by 40 percent in the last two decades. Older records, which go back to 1950, but only for white women, show that incidence and mortality rates have fallen by 75 percent since then.

Still, this year, about 15,000 women will be diagnosed with cervical cancer, and about 5,000 will die of the disease.

The numbers should be far lower, authorities say.

``We shouldn't have cervical cancer in our country,'' declared Michael Steller, a gynecological oncologist at the National Cancer Institute. ``It's preventable if you get a routine Pap smear.''

A Pap smear is a slide of cells gently scraped from the neck of a woman's uterus, or cervix.

Its developer, the late George Papanicolaou, a Cornell University Medical College researcher in cell biology, capitalized on the fact that cervical cancer is one of the few cancers with well-defined precancerous stages.

After the test was introduced in 1945, it caught on slowly, recalled John Mikuta, 71, a professor of gynecological oncology at the University of Pennsylvania Medical Center. Taking cells from a woman was easy, but analyzing them under a microscope was like looking for a needle in a haystack. In a smear of 300,000 cells, as few as 10 or 20 might be abnormal.

``Originally, it was a very laborious process,'' Mikuta said. ``It took a pathologist 30 to 40 minutes to read a slide.''

Today, specially trained technicians can do it in five or six minutes.

Indeed, to deter commercial laboratories from sacrificing accuracy to quantity, federal regulators in 1988 imposed limits on technicians' daily slide quotas, as well as other quality-assurance measures.

A reputable lab will miss about 5 percent of abnormal smears, said Michael R. Henry, a pathologist and lab director at the National Naval Medical Center in Bethesda. The safeguard for a woman who has regular tests is that abnormal cells usually take up to a decade to develop into invasive cancer.

Still, tragic mistakes have been made. Last month, a Wisconsin lab was fined for misreading the Pap tests of two women who later died.

``There's a greater awareness of the issue, and women are asking, `Why was this missed?' '' Henry said. ``I think that's good, because it makes the labs try to do better.''

If a smear is abnormal, diagnosis normally involves a colposcopy - inspection of the cervix under magnified illumination - and possibly a biopsy.

Mildly abnormal cells may revert back to normal without treatment. More severe abnormalities or early-stage cancer that has not spread usually can be completely cured by destroying the tissue with lasers, electrical treatment, cryosurgery (which uses cold), or other methods.

If the cancer has spread, a hysterectomy or radiation therapy may be recommended. Among women whose cancer has not spread very far, about 80 percent to 90 percent survive. About 60 percent of women survive late-stage, invasive cancer that involves the lymph nodes.

University of Michigan radiation oncologist Alan Lichter said: ``Tremendous progress has been made, but the thing is, this is almost completely a preventable cause of death. Cure rates approach 100 percent if it's detected before it becomes invasive.''

The American College of Obstetricians-Gynecologists recommends that most women get a Pap test every year.