Survival and prognostic factors of non-small cell lung cancer patients with postoperative locoregional recurrence treated with radical radiotherapy

Background: Locoregional recurrence remains the challenge for long-term survival of non-small cell lung cancer(NSCLC) patients after radical surgery, and curative-intent radiotherapy could be a treatment choice. This study aimed to assess the survival and prognostic factors of patients with postoperative locoregionally recurrent NSCLC treated with radical radiotherapy.Methods: We reviewed medical records of 74 NSCLC patients with postoperative locoregional recurrence who received radical radiotherapy between April 2012 and February 2016 at Sun Yat-sen University Cancer Center(Guangzhou, China). The efficacy and safety of radical radiotherapy were analyzed. The probability of survival was estimated using the Kaplan-Meier method and compared using the log-rank test. The Cox proportional hazards model was used to identify prognostic factors.Results: Grade 3/4 adverse events included neutropenia(8 cases, 10.8%), esophagitis(7 cases, 9.5%), pneumonitis(1 case, 1.4%), and vomiting(1 case, 1.4%).The 2-year overall survival, progression-free survival, local recurrencefree survival(LRFS), and distant metastasis-free survival(DMFS) rates of all patients were 84.2,42.5,70.0, and 50.9%,respectively. Univariate and multivariate analyses showed that a higher biological effective dose(BED) of radiation was associated with longer LRFS [hazard ratios(HR)=0.317,95% confidence interval(CI) = 0.112-0.899, P = 0.016] and that wild-type epidermal growth factor receptor(EGFR) was associated with longer DMFS compared with EGFR mutation(HR = 0.383,95% CI=0.171-0.855, P = 0.019).Conclusions: Radical radiotherapy is effective and well-tolerated in NSCLC patients with postoperative locoregional recurrence. High BED is a predictor for long LRFS, and the presence of wild-type EGFR is a predictor for long DMFS.