Blood Test Could Catch Cancer, Other Diseases Much Earlier

ByNed Potter

March 15, 2006 — -- Surgery. Chemotherapy. Radiation. All too often, doctors have to call out their heavy artillery because they find a disease all too late.

Take the case of Jill Gladstone, whose breast cancer has metastasized, or spread to other parts of her body.

"I wish I had found out earlier on that I had cancer, [rather] than waiting for what happened to me," she said.

Dr. Mark Greene is working on a possible solution to late-stage diagnoses. At the University of Pennsylvania School of Medicine, he and his team have developed a supersensitive blood test they call FACTT.

FACTT, shorthand for fluorescent amplification catalyzed by T7-polymerase technique, detects unusual proteins in the blood -- sometimes the first telltale signal that something is wrong.

"I think this technology will ultimately help change the way we practice medicine, in terms of dealing with the prevention of major problems," said Greene in an interview with ABC News. He and his colleagues have just published their early results in the journal Nature Medicine.

Greene said the new test could be 100,000 times more sensitive than the most commonly used existing blood test, known as ELISA, for enzyme-linked immuno adsorbent assay. It would piggyback, in effect, on the ELISA test, making it relatively simple for laboratories to carry out.

If FACTT can find traces of unusual proteins or other molecules in the bloodstream, that might ultimately make it possible to pick up signs of Alzheimer's disease before it creates brain damage. It might pick up the errant proteins created by the human form of mad cow disease. It might also make it possible to find a cancer before a tumor shows up on a mammogram or other X-ray.

Breast cancer often causes small amounts of a protein called Her2/neu to be "expressed," or spread, through the body. In one early experiment, the ELISA test detected Her2/neu in two out of 10 women tested; the FACTT test caught it in nine out of 10.

"Our goal is really to identify problems at a very early stage," Greene said.

If anything, some doctors worry the FACTT test might be too sensitive, causing patients to worry even though they might not need treatment. Some cancers are so small the immune system actually destroys them without anyone knowing.

"What we don't want to do is have a test that shows an abnormality, that detects the presence of a cancer cell, and will never matter to that woman," said Dr. Eric Winer, director of the breast oncology center at the Dana-Farber Cancer Institute in Boston. "We have to be very careful that these tests are going to give us accurate information, and that they're not going to over diagnose and lead to over treatment and perhaps unnecessary treatment."

FACTT is still at least two or three years from routine use; the first steps in organizing clinical trials have just begun.

But if everything works out, the researchers said the test could be simple and relatively affordable. And maybe, if it catches disease more quickly, treatment could be simpler too.

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