A painless, 20-second test could save more than 100, 000 lives annually in the United States by detecting lung cancer at an early, curable stage, say researchers at Weill Medical of Cornell University and New York Presbyterian Hospital.

A University of Iowa study showing the analysis of sputum a low-cost, low-risk method for detecting lung cancer -- makes more sense as an initial diagnostic test for many patients than the more expensive invasive methods.

Researchers at New York Hospital/Cornell Medical Center and New York University Medical Center created the Early Lung Cancer Action Program to screen 1, 000 smokers and former smokers. Twenty-two cancers were detected using CT; 17 of those (77 percent) were not visible on chest X-ray, the standard diagnostic imaging technique.