Toronto: Lung cancer may now be detected early with a simple blood test, doing away with the need for invasive biopsies, according to new study by an Indian American. "These findings suggest that lung cancers interact with circulating white blood cells and change the types of genes that are active in these cells," explained Anil Vachani of the University of Pennsylvania.

"We found that the types of genes present in these cells could tell us whether or not cancer was present," he added.

The finding can be potentially used to develop a non-invasive diagnostic and painless test for patients suspected of having lung cancer, he noted.

The possibility of developing such a test to differentiate between cancerous and benign lesions has enormous implications for the world of medicine and those awaiting conclusive biopsy results after preliminary testing.

"CT screening results in the detection of lung nodules in 20 to 60 percent of subjects," said Vachani. "This high false-positive rate requires patients to undergo extensive follow-up investigations, such as serial CT scans, PET scans or biopsies. This test may be able to obviate the need for such things if it is developed into a large-scale diagnostic tool."

Lung cancer is a very diverse disease, and screening for it can be very difficult. Vachani hoped to identify a stable and consistent way of determining the presence of lung cancer by testing for the gene expression of white blood cells.

Rather than screening for factors released by the tumour into the blood stream, the test Vachani used looked at gene expression in the subject's own circulating white blood cells.

To test the accuracy of the method, the researchers studied 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 percent.

"If our results are encouraging, we would like to test this in a prospective clinical trial," Vachani said.

Findings of the study were unveiled on Tuesday at the American Thoracic Society's International Conference here. IANS