Jewish World Review Nov. 25, 2002 / 20 Kislev, 5763

New technique detects ovarian cancer

By Joe Grossman | (UPI) A new technique, tested for the first time with humans, has detected ovarian cancer reliably and might be able to uncover many other forms of cancer, researchers said.

The researchers took blood samples from women known to have various stages of ovarian cancer as well as from healthy individuals. In 87 percent of the women with early stage ovarian cancer -- and in 95 percent with late stages of the disease -- the test detected cancer. No person without cancer received a positive result and the method's reported accuracy is higher than existing ovarian cancer tests

"The method can be used to identify whether there is cancer or not, but we cannot specify which kind of cancer the patient has," Ie-Ming Shih, a pathologist at Johns Hopkins School of Medicine in Baltimore, told United Press International.

"If a person has a positive test then the patient needs to consult his or her primary care physician and further tests can be done, such as CT scan, MRI or other tests," said Shih, who directed the study. "This is better than not knowing that the patient has cancer until he develops cancer symptoms, which is too late."

The results of the pilot study of the test, which cost $300 per person and involved 54 women with ovarian cancer and 31 healthy subjects, will appear in the Nov. 20 issue of the Journal of the National Cancer Institute.

More clinical trials are needed before U.S. Food and Drug Administration approval is sought, Shih said, adding work is proceeding on lowering the cost. The test counts small gene building blocks, called nucleotides, that occur in every cell.

Almost all genes come in pairs called alleles -- one from the mother and one from the father. In healthy cells, alleles occur in equal numbers from both parents. But in cancer cells, and their material found in the blood, the balance is upset.

The test, called digital SNP analysis, determines the ratio of the alleles by detecting specific nucleotides, known as single nucleotide polymorphisms, that are known to fall out of balance in many forms of cancer. When one allele occurs 50 percent more often than the other, the test considers this a positive result for cancer.

"This is the first use of this technology as a diagnostic tool for cancer," Dr. Elizabeth Swisher, a gynecological cancer specialist, told UPI. "There's a long way to go before it's validated to know that it can be used as a screening test, but it really shows promise," said Swisher, who is researching diagnostic cancer testing at the University of Washington in Seattle and the Seattle Cancer Care Alliance.

"Clearly, if we can pick up ovarian cancer when it's stage I, when it's 80- to 90-percent curable, instead of when it's stage III, when it's 10- to 20-percent curable, that's a huge advance in medicine," said Dr. Jonathan S. Berek, chief of gynecologic oncology at the David Geffen School of Medicine at the University of California, Los Angeles. It is too early to tell if the test will prove effective in larger studies, Berek said.

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© 2002, United Press International