Gene Expression in White Cells Indicates Lung Cancer

The simple blood test could accurately detect lung cancer in its earliest stages.

The possibility of developing a noninvasive test to distinguish cancerous from benign lesions in the lungs has enormous implications, not just for the world of medicine, but also for every patient who has gone through the distressing experience of having to wait for conclusive biopsy results after preliminary testing.

Because lung cancer is a very diverse disease, screening for it can be very difficult, Dr. Anil Vachani assistant professor of medicine at the University of Pennsylvania Medical School (Philadelphia, PA, USA) said, " CT [computed tomography] screening results in the detection of lung nodules in 20 to 60% of subjects. This high false-positive rate requires patients to undergo extensive follow-up investigations.” He and his colleagues decided to look at the gene expression in the patient's circulating blood cells rather screening for factors released by the incipient tumor into the blood stream. "We found that the types of genes present in these cells could tell us whether or not cancer was present,” explained Dr. Vachani.

To test the accuracy and validity of the method, the team recruited 44 patients with early stage lung cancer and 52 control subjects who were matched for age, smoking status, gender, and race. They then used a number of genetic arrays to determine the best targets for detecting the presence of cancer. They found that a 15-gene array had the highest accuracy, at 87%.

"These findings suggest that lung cancers interact with circulating white blood cells and change the types of genes that are active in these cells. This finding can be potentially used to develop a noninvasive diagnostic test for patients suspected of having lung cancer,” said Dr. Vachani.

This study was presented at the American Thoracic Society's 2008 International Conference in Toronto (ON, Canada) on May 20, 2008.


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University of Pennsylvania Medical School