When and how often should women get a Pap test -- the test that helps detect cervical cancer?

Women and their physicians have been grappling with that question for the past several years, and last week they got some help from a group of medical organizations that issued a new set of guidelines about Pap tests.

The American College of Obstetricians and Gynecologists, the American Cancer Society, the American Medical Association and the National Cancer Institute were among those organizations who teamed up to release new, uniform recommendations for Pap tests.

Under these guidelines, Pap tests should:

Begin when a woman becomes sexually active or when she turns 18 years old -- whichever occurs first.

Be given annually until three normal results are obtained over three consecutive years. After that, it's up to the woman and her physician to decide how often to repeat the Pap test.

High-risk women -- those who have multiple sex partners or whose sexual partner has multiple sex partners -- need to continue to have annual Pap tests performed, the organizations recommend. Although it is not yet understood why, having multiple sexual partners increases the risk of developing cervical cancer. Other women at high risk include the daughters of women who took DES -- diethylstilbesterol -- during pregnancy, those with a history of venereal warts and women who began sexual activity before age 18.

In the past 40 years, Pap tests have helped the death rate from uterine cancer decline 70 percent, according to the American Cancer Society. Yet 15 to 20 percent of American women still do not have regular Pap tests. "The majority of women who develop invasive cervical cancer have not had this test," said Dr. Harmon J. Eyre, cancer society president.

An estimated 12,900 women are expected to get cervical cancer this year, according to the American Cancer Society. When it is caught early -- most often through a Pap test -- cervical cancer is largely curable. But because many women don't get the test -- or because positive results are sometimes missed by laboratories -- an estimated 7,000 American women die of cervical cancer each year.

The Pap smear is a simple, painless test. A few cells are scraped from the mouth of the cervix, placed on a slide and analyzed under a microscope.

Recent concerns about the accuracy of some high-volume, cut-rate laboratories have worried medical experts and consumers.

To address the recent concern over accuracy of Pap tests, the College of American Pathologists also recommended last week that women ask these questions when the test is performed:

Is the laboratory licensed, accredited and inspected?

Is the laboratory report available for me to read?

When it receives an unsatisfactory specimen -- one with too few cells, for example -- does the lab do the test anyway or ask for another sample? The pathologists say a second sample is necessary in such cases.

Is adequate laboratory staff available to perform the test?

Is there proof of good quality assurance at the laboratory?

Is there good communication between the laboratory and my physician?

Is the laboratory close enough to my doctor's office to facilitate communication?