A story in last week's Health section may have conveyed the impression that Marilyn Quayle underwent surgery for invasive cervical cancer, which affects 14,000 women annually. The Vice President's office announced last week that Quayle's wife had a hysterectomy for severe dysplasia, a cell abnormality that can be a precursor to cervical cancer. (Published 7/31/90)

Medical experts say that Marilyn Quayle's surgery for cervical cancer underscores the need for women to have an annual Pap smear, one of the oldest -- and often most misunderstood -- screening tests for cancer.

Many women do not understand the scope of problems that can be detected by the Pap test. These range from a variety of infections to invasive cancer of the cervix.

Pap smears also tend to give false readings in a significant number of cases. About 10 to 15 percent of the time, the results do not reflect a problem when one exists. This is why Pap smears need to be repeated at regular intervals, usually each year, once a woman has become sexually active.

"That way if they get a false negative test result this year, it will be picked up the next year," said Ralph M. Richart, chief of gynecological pathology and cytology at the Columbia-Presbyterian Medical Center in New York City.

Introduced in 1943 by Greek-born George Papanicolaou, the Pap smear has been credited with saving thousands of lives. "We have made an enormous impact in reducing the incidence and mortality of cervical cancer," said Robert Kurman, professor of obstetrics and gynecology at the Johns Hopkins Medical Institutions in Baltimore.

Deaths from cervical cancer have dropped 70 percent since the test was introduced, according to the American College of Obstetricians and Gynecologists (ACOG). The disease strikes 14,000 American women a year and causes 6,800 deaths.

What's more, public health officials estimate that 90 percent of these deaths could be prevented if more women had regular Pap smears. A 1983 national survey showed that only 57 percent of women, ages 40 to 70, had a Pap smear at least once every three years. In younger women, nearly 80 percent had regular Pap tests.

In the vast majority of cases, abnormal Pap test results do not indicate cancer but precancerous conditions of the cervix, Richart said. Since it takes an average of 10 years for most of these precancerous cells to develop into full-blown cervical cancer, early detection and prompt treatment are usually enough to cure the disease.

In addition, a growing number of studies since the mid-1970s have shown that many abnormal Pap test results are actually caused by infections with human papilloma virus (HPV), a sexually transmitted disease. More than 22 different strains of HPV have now been identified in the female genital tract. Many cause no apparent symptoms, but others produce genital warts and can lead to cancer. Estimates are that "between 40 to 90 percent of cervical cancers are now related to HPV infections," said George Malkasian, past president of ACOG and a senior consultant to the Mayo Clinic's department of obstetrics and gynecology.

Because of this, many physicians are now advising women with abnormal Pap smears and those with cervical cancer to have their sexual partners tested. "We find that a significant number of the partners of women with abnormal Pap smears {are also affected}," said Columbia-Presbyterian's Richart.

The examination for male partners, called an androscopy, is usually performed by a specially trained dermatologist. Treatment involves the use of topical drugs, such as podophyllin or trichloroacetic acid. In cases where the man is found to have precancerous cells, laser therapy is used to kill the cells.

In Malkasian's view, women who have an abnormal Pap test should ask their physicians if it is related to an HPV infection. "If the answer is yes, then they should ask, 'Should my husband or partner be tested too?' " he said.

Doctors also have a new test to detect HPV infections in women -- the Virapap. Gynecologists perform the Virapap the same way they do a regular Pap smear. They scrape cells from the cervix, the lower part of the uterus, which is the doorway to the vagina, place the cells on a slide and send them to a laboratory for analysis. Instead of looking for abnormal cells as the Pap test does, the Virapap detects genetic material from the human papilloma virus, and in many cases can identify which strain is present.

After one abnormal Pap smear result, the test is usually repeated to confirm the findings. Some doctors are now recommending that a colposcopy be performed after the first abnormal smear. This relatively painless procedure involves examining the cervix under magnification. It takes about 10 to 20 minutes to perform in the doctor's office.

During the colposcopy, which means literally looking at the cervix, doctors search for abnormal-appearing cells, particularly in the endocervical junction -- a region located inside the cervix, near the floor of the uterus. It is at the junction -- also known as the transformation zone -- where cervical cancer is most likely to arise.

As part of the colposcopic exam, doctors often sample or biopsy a small portion of suspicious-looking tissue. Test results are available in a week to 10 days.

When the diagnosis is a precancerous condition or related to an HPV infection, "most of the time, these patients can be treated in the office," Richart said. Usual therapy is cryosurgery -- literally killing the abnormal cells by freezing. Another option is laser surgery, which also destroys the cells. Both procedures take about 20 minutes to perform.

If the abnormal cells involve a large area or extend high into the cervical canal close to the uterus, doctors usually turn to a more invasive procedure called conization. This therapy is performed under general anesthesia and involves either an overnight stay in the hospital or treatment in a same-day surgery unit. In conization, doctors remove a cone-shaped piece of tissue around the abnormal cells. Childbearing is not affected by this procedure.

For most women, treatment is successful. Only about "one in 500 will ultimately require a hysterectomy," he said.

In a minority of women who have an abnormal Pap test, doctors find that the cancer has already grown about an eighth of an inch into the surface of the cervix or that it is a relatively fast-growing type of cervical cancer. Treatment for these women is a hysterectomy that removes the uterus and cervix.

If more invasive cancer is present, then doctors will also remove nearby lymph nodes, as well as the cervix and uterus. Another option is radiation therapy, which is about as effective as surgery for advanced cervical cancer.

For most women, however, regular Pap smears can assure that this kind of surgery is not necessary.

"The overwhelming majority of women -- if they have Pap smears taken on a regular basis -- will have abnormalities detected in a stage when they can be readily treated and are virtually treatable 100 percent of the time," Richart said.