Biomarkers in blood aid lung cancer diagnosis
By David Douglas
NEW YORK (Reuters Health) - Four proteins in the blood appear to be useful in helping to establish a diagnosis of lung cancer, North Carolina-based researchers report in the Journal of Clinical Oncology.
Lead investigator Dr. Edward F. Patz, Jr., told Reuters Health that his group believes that a combination of these biomarkers may be helpful in determining the probability of lung cancer in patients whose diagnosis can't be determinate by imaging studies.
Patz and colleagues at Duke University Medical Center, Durham note that currently there is no blood test for lung cancer, but blood biomarkers could be "enormously valuable."
In an effort to develop appropriate biomarkers, the researchers investigated six serum proteins and found that four, collectively, were promising -- carcinoembryonic antigen, retinol binding protein, alpha-1-antitrypsin, and squamous cell carcinoma antigen.
The team examined blood samples from 50 patients with newly diagnosed lung cancer and 50 "controls" without lung cancer. A validation set of 49 patients and 48 controls were also investigated.
Measurement of the four protein markers correctly classified all of the patients and controls at least 75 percent of the time.
The researchers used a "classification tree" to help them determine the probability of cancer based on protein levels. "People whose samples landed in one of three bins at the bottom of the tree had a 90-percent chance of having cancer," said Patz in a statement. "Other bins indicated risks as low as 10 percent."
Patz concluded that "additional trials will help us refine the role of this panel in diagnosing patients with lung cancer."
SOURCE: Journal of Clinical Oncology, December 10, 2007.