A promising experimental test of genetic material in sputum may soon let clinicians detect and treat lung cancer at an earlier, more curable stage. In studies, the test identified 65% of people who developed lung cancer up to 18 months later, but it also yielded false-positive results 35% of the time.

Researchers have identified six genes that can predict lung cancer development. Among people in whom three or more of these six genes were inactivated, the risk of developing lung cancer increased more than sixfold.

Currently, just 15% of patients with lung cancer survive 5 years beyond diagnosis because the disease is typically diagnosed at an advanced stage.

Source: Promoter hypermethylation of multiple genes in sputum precedes lung cancer incidence in a high-risk cohort, Cancer Research, SA Belinsky, et al., March 15, 2006.