Secondary Primary Lung Cancer After Esophageal Cancer: A Population-Based Study of 44,172 Patients
Abstract Background: The present study aimed to assess the incidence, characteristics, and survival of secondary primary lung cancer after primary 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 to 2016. The risk of secondary primary lung cancer using standardized incidence ratio (SIR) was calculated among patients with EC. Overall survival and characteristics were compared between patients with EC-LC and patients with LC-1.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). There was a significant difference with regard to the year of diagnosis, sex, grade and stage between the secondary primary lung squamous carcinoma after EC (EC-LUSC) and first primary lung squamous carcinoma (LUSC-1) patients. A statistically significant difference with respect to race, sex, age, year, grade and stage was found between the secondary primary lung adenocarcinoma after EC (EC-LUAD) and first primary lung adenocarcinoma (LUAD-1) patients. A history of EC was found to be an independent risk factor of death for lung squamous carcinoma and lung adenocarcinoma patients in localized stage based on multivariate Cox regression analysis, propensity score-matching analysis and multiple imputation.Conclusion: 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 EC-LUSC and EC-LUAD. Clinicians should moderately strengthen lung tissue protection during the management of EC patients.