Second primary lung cancers: Analysis of E5597 selenium chemoprevention study.

7518 Background: Non-small cell lung cancer (NSCLC) patients that undergo curative resection are at risk for development of second primary lung cancer (SPLC). The E5597 trial is the largest placebo-controlled lung cancer chemoprevention study conducted in the US. We report on the SPLC diagnosed in this cohort. Methods: E5597 randomized 1,561 (2:1) patients with resected stage I NSCLC to selenium or placebo for a total of four years with the primary objective of decreasing the incidence of SPLC. The study was stopped at first interim analysis for futility in October 2009. The participants were followed for incidence of all second primary tumors (SPT). Results: There were 290 (19%) incidences of SPT, of which 113 (7.2%) were SPLC among 112 cases (1 case with 2 incidences) as of January 2014 with median follow-up time of 5.6 years. 82 incidences in 81 cases occurred in the selenium arm (S) and 31 cases in the placebo arm (P). The median age was 67 years, and there were a higher proportion of women (52.7%). A...