Twenty-Year Follow-Up of Lung Cancer Screening by CT

The International Early Lung Cancer Action Project (I-ELCAP) is a nonrandomized study in which smokers were screened with annual low-dose computed tomography (CT). The study began in 1992, and in a previous report, estimated lung cancer–specific 10-year survival was 80% among participants diagnosed with lung cancer (NEJM JW Oncol Hematol Feb 2007 and N Engl J Med 2006; 355:1763).

Now, the researchers have reported even longer follow-up. Lung cancer was diagnosed in 1.4% of 89,000 participants (median age, 66; median smoking history, 43 pack-years), and 81% of those cases were clinical stage 1. Estimated 10-year and 20-year lung cancer–specific survival were both 81%. In the subgroup with pathologic stage T1aN0M0, 20-year lung cancer–specific…