The test isn't ready for lung cancer screening. But if it succeeds in further studies, the test may help detect lung cancer at an earlier, and more treatable, stage.
That's the goal of Edward Patz Jr., MD, and colleagues. They point out that lung cancer is the No. 1 cause of cancer death and that because there aren't any lung cancer screening tests, patients are often diagnosed when their cancer has become hard to treat.
"We talk about how devastating this disease is all the time, but we still don't have a screening system in place that can detect lung cancer early, without exposing patients to the risks of biopsy and surgery," Patz says in a news release.
"This study is an important step in the right direction," he says.
Lung Cancer Blood Test
Patz and colleagues analyzed blood from almost 100 people. The group included 49 people who had already been diagnosed with lung cancer and 48 people without lung cancer.
The researchers compared levels of certain proteins in the blood samples of people with and without lung cancer.
Four proteins -- called CEA, RBP, SCC, and AAT -- stood out in the lung cancer patients' blood. All of those proteins have been linked to lung cancer.
Each protein, by itself, wasn't good at distinguishing between people with and without lung cancer. But together, the proteins made that distinction more than 80% of the time.
The panel of proteins needs to be tested in larger studies. And it won't diagnose lung cancer by itself; instead, it checks the likelihood that a person has lung cancer. Further tests will be needed to confirm the presence of lung cancer, note the researchers.
Their study appears in the Journal of Clinical Oncology.
Other scientists are also working on lung cancer blood tests. In September, one group reported promising results from analyzing a different blood protein, called HAAH.
Another team of researchers are developing a breath test to help detect lung cancer.