Protein analysis helping doctors tailor treatment to individual

SAN FRANCISCO -- A new way of analyzing tumors to see which proteins they produce shows promise in helping doctors tailor treatments for each patient's cancer.

The idea is to see which proteins the cancer uses to fuel its out-of-control growth. That, in turn, would help doctors prescribe medicines that specifically block them.

Many new drugs in development are precisely aimed at the abnormalities that make cancer different form normal tissue. However, these defects vary from person to person, and any single drug is expected to help only a minority of patients.

Researchers from the Clinical Proteomics Program, operated by the Food and Drug Administration and the National Cancer Institute, described progress with the approach recently at the American Association for Cancer Research meeting in San Francisco.

They analyzed patients' cancer cells, drawn from tumors with a needle, to see which proteins they are making.

"We will biopsy patients before, during and after therapy to monitor treatment and to change it if we need to. It's a new paradigm we are testing," said Dr. Emanuel Petricoin, the program's co-director.

So far, they have analyzed 19 patients being treated for breast and ovarian cancer. The patients receive the drug Herceptin, followed a month later by Taxol.

Petricoin said protein profiles will be used to help figure out which patients are likely to respond to new drugs.