Is cancer history really an exclusion criterion for clinical trial of lung cancer? Influence of gastrointestinal tract cancer history on the outcomes of lung cancer surgery

Objective: Exclusion of patients with a history of other cancer treatment except in situ situation has been considered to be inevitable for clinical trials investigating survival outcome. However, there have been few reports confirming these influences on surgical outcome of lung cancer patients ever. Methods: Multi-institutional, individual data from patients with non-small cell lung cancer resected between 2000 and 2013 were collected. The patients were divided into two groups: those with a history of gastrointestinal tract cancer (GI group) and those without any history (non-GI group). We compared the outcomes with well-matched groups using propensity scoring to minimize bias related to the nonrandomness. The influence of gastrointestinal tract cancer stage, disease-free interval, and treatment method for gastrointestinal tract cancer on the surgical outcome of non-small cell lung cancer was examined. Results: We analyzed 196 patients in the GI group and 3732 in the non-GI group. In unmatched cohort, multivariate analyses showed that a history of gastrointestinal tract cancer did not affect overall survival or recurrence-free survival. Independent predictors of poor prognosis included older age, male sex, high carcinoembryonic antigen levels and advanced clinical stage of non- small cell lung cancer. The two groups in the matched cohort demonstrated equivalent overall survival and recurrence-free survival, even in patients with clinical stage I. Gastrointestinal tract cancer stage, disease-free interval and treatment method for gastrointestinal tract cancer were not associated with outcomes. Conclusions: History of early gastrointestinal tract cancer completely resected is not always necessary for exclusion criteria in clinical trial of lung cancer.