Secondary primary lung cancer after esophageal cancer: a population-based study of 44,172 patients

Background The present study aimed to assess the survival, incidence, and characteristics of secondary primary lung cancer (SPLC) after esophageal cancer (EC-LC). Methods The patients with esophageal cancer (EC) who developed SPLC and patients with first primary lung cancer (LC-1) were retrospectively reviewed in the Surveillance, Epidemiology, and End Results 18 registries covering 2000-2016. Overall survival and characteristics were compared between patients with EC-LC and patients with LC-1. The independent relation between a history of EC and death was evaluated by calculating hazard ratios in multivariate Cox regression analysis propensity score-matching analysis, and multiple imputation for cases with missing information. Results In comparison with the general population, the patients with EC had a higher risk for developing secondary primary lung cancer (SIR =1.86, 95% confidence interval (CI): 1.69-2.05). A history of EC was found to be an independent risk factor of death for lung squamous carcinoma (LUSC) and lung adenocarcinoma (LUAD) patients in localized stage based on multivariate Cox regression analysis, propensity score-matching analysis and multiple imputation. Conclusions There is a significantly increased risk of secondary primary lung cancer in EC survivors and a history of EC adversely affects overall survival in individuals who subsequently develop localized LUSC and LUAD. Clinicians should moderately strengthen lung tissue protection during the management of EC patients.