Effect of thoracic radiotherapy dose on the prognosis of advanced lung adenocarcinoma harboring EGFR mutations

Abstract

Background The aim of this study was to investigate the effects of different thoracic radiotherapy doses on OS and incidence of radiation pneumonia which may provide some basis for optimizing the comprehensive treatment scheme of these patients with advanced EGFR mutant lung adenocarcinoma. Methods Data from 111 patients with EGFR-mutant lung adenocarcinoma who received thoracic radiotherapy were included in this retrospective study. Overall survival (OS) was the primary endpoints of the study. Kaplan–Meier method was used for the comparison of OS. The Cox proportional-hazard model was used for the multivariate and univariate analyses to determine the prognostic factors related to the disease. Results The mOS rates of the patients, who received radiotherapy dose scheme of less than 50 Gy, 50–60 Gy (including 50 Gy), and 60 Gy or more were 29.1 months, 34.4 months, and 51.0 months, respectively (log-rank P = 0.011). Although trend suggested a higher levels of pneumonia cases with increasing radiation doses, these lack statistical significance (χ2 = 1.331; P = 0.514). The multivariate analysis showed that the thoracic radiotherapy dose schemes were independently associated with the improved OS of patients (adjusted hazard ratio [HR], 0.606; 95% CI, 0.382 to 0.961; P = 0.033). Conclusions For the patients with advanced EGFR-mutant lung adenocarcinoma, the radical thoracic radiotherapy dose scheme (≥ 60 Gy) could significantly prolong the OS of patients during the whole course management.