Women get annual mammograms to spot breast cancer and pap smears for cervical cancer. Now doctors believe that as early as 18 months from now, a routine test to detect ovarian cancer may also be available.

The new tests, which could cost as little as $125 and are due in doctors' offices by late next year, have the potential to eliminate much of the guessing that now goes into detecting ovarian cancer. Doctors often are slow to diagnose the disease because symptoms like abdominal cramps, bloating and fatigue also can show up in healthy patients -- and surgery is the only sure-fire way to know if cancer is present.

Most ovarian cancer patients today survive only one year after diagnosis, primarily because the disease isn't usually detected until after it has spread beyond the ovary. The five-year survival rate, which is only 29% when the cancer is detected at an advanced stage, shoots up to 95% when the disease is diagnosed early.

An ovarian-cancer screen, says Holly Gallion, a specialist in ovarian cancer at Magee-Womens Hospital in Pittsburgh, "has the potential to be the next pap smear" -- a fast and affordable test that could virtually wipe out a deadly disease.

The development comes as debate over some cancer-screening tests is escalating. Any disease-detection screen produces some number of so-called false positives -- results that look like cancer but really aren't. That has been one argument against using the PSA blood test to screen men for prostate cancer. The wisdom of annual mammograms also has come under question by critics who say they haven't led to overall declines in death rates from breast cancer.

With the new ovarian-cancer tests, the dilemma facing women and their doctors will be even tougher. Because ovarian cancer is relatively uncommon, even a small percentage of false positives would mean incorrect diagnoses for a large number of women who actually aren't sick. As a result, some oncologists worry that too many women would undergo unnecessary surgery if the new tests become routine.

But improved detection methods are crucial to ending the hit-or-miss approach doctors are stuck using today. After discovering cysts during a routine exam, Lauren Ginsberg's doctor recommended birth-control pills to try to reduce them before proceeding with surgery. The treatment made sense, since she had no family history of ovarian cancer and wasn't suffering from the usual symptoms.

For most women, that would have been the end. But Ms. Ginsberg had an intuition that something was wrong and opted for immediate surgery. Ovarian cancer was found. "Later, my doctor told me if I had waited even a few months to have surgery, I would be dead today," says Ms. Ginsberg, now 30 years old and program manager for membership at Gilda's Club in New York, part of a nationwide network of ovarian-cancer support groups.

Researchers developing the tests acknowledge the potential problems and say they plan to offer them at first only to women who are considered at high risk of developing ovarian cancer. Only after the tests prove effective with those women would they then be rolled out as a general screening tool that could become part of a woman's annual physicals or gynecological check-ups.

The tests start by simply drawing blood from a patient's finger. The most widely anticipated test, developed by Correlogic Systems, of Bethesda, Md., and the federal government's Clinical Proteomics Program, uses powerful mathematical algorithms to zero in on protein patterns that indicate ovarian cancer. Another test focuses on identifying certain proteins or other substances that appear elevated in women with early stages of the cancer.

The Food and Drug Administration hasn't approved any of the new tests yet, but early results are encouraging. Atairgin Technologies, of Irvine, Calif., says preclinical trials indicate that its test evaluating levels of several naturally occurring molecules in the body can detect ovarian cancer at the earliest stages. In anticipation of the new tests and others that could follow, pending legislation in Congress calls on federal health officials to approve a new ovarian-cancer test and for insurers to pay for it once it is available.

Blood tests for ovarian cancer aren't entirely new. But an existing test that looks for elevated levels of a certain protein is approved only for women who already have had ovarian cancer -- and isn't considered reliable for finding early-stage ovarian cancer anyway. As a result, most cases of the cancer aren't discovered until it has spread beyond the ovaries, dramatically increasing the chance of death.

The new tests may have their own problems. A study published in Lancet, a British medical journal, in February showed a false positive rate of about 5%. Peter Levine, Correlogic's president and chief executive, says a follow-up test of the same samples used for the Lancet study produced 100% accuracy -- and no false positives. The difference came from improving handling procedures for the samples, he says, though those results haven't been published yet.

"False positives can wreck lives," says Maurie Markman, director of the Cleveland Clinic Cancer Center and an ovarian-cancer specialist. "A screening test ... has to be at least 99% specific when dealing with a disease like this."

Meanwhile, efforts also are under way to produce better results with the existing blood test for ovarian cancer, which costs about $150 and has the advantage of already being widely available. Research by Steven J. Skates of Harvard Medical School and Massachusetts General Hospital in Boston indicates that it might be possible to spot ovarian cancer sooner by looking for unusual changes in those test results over time.

Write to Amy Dockser Marcus at amy.marcus@wsj.com¹²

Updated October 1, 2002