WASHINGTON, February 2, 2004  - Imagine a blood test that could detect the earliest signs of ovarian cancer to help far more women survive. Or one that could prevent thousands of aging men from undergoing unnecessary biopsies for prostate cancer.

Those tests are moving toward reality, thanks to new technology that can spot early signals in drops of blood.

The National Cancer Institute has begun a major study to prove if the blood test detects early relapse in ovarian cancer patients. Relapse occurs dismally often, and if the test works as well as earlier research suggests, it could win Food and Drug Administration approval for that use within a few years.

It would take longer to prove to FDA’s standards whether the test also can spot ovarian cancer the first time it strikes.

Ovarian cancer is a malignant tumor that begins in a woman’s ovaries, two almond-sized organs located on each side of the pelvis that produce eggs and are the main source of the female hormones estrogen and progesterone. In cancer, ovarian cells grow out of control and usually form a tumor.

There are three main types of ovarian tumors – some of which are benign and some are malignant -- named for the kind of cells they start from. The most common type of tumor, an epithelial tumor, begins in the cells that cover the surface of the ovary. Ovarian tumors can also begin in the egg-producing cells (germ cell tumors) and in the supportive tissue surrounding the ovaries (stromal tumors), but these types of cancer are rare.

Cells from an ovarian tumor can break away and spread to other parts of the body.

The American Cancer Society estimates that there will be about 23,300 new cases of ovarian cancer in the United States in 2002. It ranks fifth as the cause of cancer death in women, and kills more women than any other reproductive organ cancer. About 13,900 women will die of the disease this year

The exact causes of ovarian cancer are not known. However, studies show that certain factors may increase the chance of developing the disease:

• Family history. A mother, daughter or sister of a woman who has had ovarian cancer is at increased risk of developing the cancer themselves. The risk is somewhat less, but still above average, if other relatives have had ovarian cancer. A family history of breast or colon cancer is also tied to an increased risk of ovarian cancer.
  

• Age. Most ovarian cancers occur in women over the age of 50, with the highest risk in women over 60.
  

• Childbearing. Women who have never had children are more likely to develop ovarian cancer than women who have had children.
  

• Personal history. Women who have had breast or colon cancer may have an increased risk for developing ovarian cancer.
  

• Hormone replacement therapy. Some evidence suggests that women who use HRT after menopause may have a slightly increased risk of developing ovarian cancer.

• Ovarian cancer often shows no obvious signs or symptoms until late in its development. Signs and symptoms of ovarian cancer may include:
  

  • General abdominal discomfort and/or pain (gas, indigestion, pressure, swelling, bloating, cramps)
    

  • Nausea, diarrhea, constipation, or frequent urination
    

  • Loss of appetite
    

  • Feeling of fullness even after a light meal
    

  • Weight gain or loss with no known reason
    

  • Abnormal bleeding from the vagina
    These symptoms may also be caused by other, less serious conditions. It is important to discuss them with a doctor.

  • The sooner ovarian cancer is found and treated, the better a woman's chance for recovery. But ovarian cancer is hard to detect early as many women have no symptoms until the disease is in an advanced stage.

    Scientists are exploring a non-invasive computer-assisted technique that analyzes protein patterns in the blood. In a recent small trial, the 30-minute blood test identified all of the patients with ovarian cancer, even those in the earliest stages of the disease.

    Researchers also are looking into the usefulness of measuring the level of CA 125, a substance called a tumor marker, which is often present in higher-than-normal amounts in the blood of women with ovarian cancer as well as evaluating transvaginal ultrasound, a test that may help detect tumors early.

    If there is any reason to suspect ovarian cancer, doctor currently use CT scans, MRI scans and biopsy to diagnose the disease.

    The chances of survival from ovarian cancer are better if the cancer is found early. If the cancer is found and treated before it has spread outside the ovary, 95 percent of women will survive at least five years. However, only 25 percent of ovarian cancers are found at this early stage. About 78 percent of all women with ovarian cancer survive at least one year after the cancer is found, and over half survive longer than five years.

Labs to begin offering test soon
Two national testing laboratories aren’t waiting. Later this year, Quest Diagnostics and LabCorp hope to begin offering the blood test, by prescription, for women at high risk of ovarian cancer because of genetic or family history.

Despite caution from the test’s own inventors that it’s not yet ready for wide use, federal law allows those labs to offer tests that aren’t FDA-approved provided they meet other government certification standards, which they’re now attempting to do.

How does the testing work? It’s called proteomics, the study of all proteins in living cells Proteins are molecules that do the body’s work by directing cells’ actions. Scientists have long used single aberrant proteins as a signal, or biomarker, for different diseases — such as PSA, or prostate specific antigen, used to screen men for prostate cancer.

But one protein gone bad seldom is definitive. Indeed, most men with elevated PSA levels don’t have cancer but a benign enlarged prostate. Too often, it takes a surgical biopsy to tell.

About the new method
The new method: Proteins usually work through networks of circuit boardlike interactions that leave behind microscopic patterns. In a unique collaboration, scientists at the cancer institute and FDA discovered how to measure those patterns with special technology that picks out protein fragments floating in blood, patterns that can show when normal cells have turned cancerous.

“There is a wealth of information in the blood that we didn’t know about before,” says NCI’s Dr. Lance Liotta, who co-directs the program. “We’re finding an ocean of biomarkers.