Blood test for detecting breast cancer shows promise. (Investigational Test Uses Proteomics).

SAN ANTONIO--Asimple blood test for breast cancer detection that's substantially more accurate than mammography is drawing closer to clinical reality.

And that's not all. The same proteomics technology being harnessed to detect breast cancer using a single drop of a patient's blood is also yielding tantalizingly high-sensitivity and high-specificity tests for the diagnosis of ovarian, lung, and prostate cancers in early clinical testing, investigators reported at a breast cancer symposium sponsored by the San Antonio Cancer Institute.

Proteomics utilize protein-based chips and high-throughput mass spectrometry to analyze millions of combinations of cellular protein expression to identify characteristic protein pattern "fingerprints" associated with various solid tumors.

The underlying concept is that certain identifiable patterns of protein expression-reflect the deranged cellular circuitry that defines a particular type of malignancy. And unlike DNA microarray analysis, another novel molecular diagnostic technology, proteomics provides direct data on tumor and/or host interactions, explained Emanuel F. Petricoin III, Ph.D., who is codirector of the Food and Drug Administration and National Cancer Institute clinical proteomics program in Rockville, Md.

Working with collaborators at various universities and biotech companies around the country, Dr. Petricoin and his associates have developed a protein pattern "fingerprint" for breast cancer that they have tested in a single drop of blood obtained from 117 breast cancer patients and 99 with biopsy-proved benign breast disease, all of whom had abnormal breast-imaging findings.

The program is a joint translational medicine project aimed at moving proteomics from the research laboratory into clinical practice.

The blood test performed with 90% sensitivity and 71% specificity for detection of breast cancer.