Mortality after radiotherapy or surgery in the treatment of early-stage non-small-cell lung cancer: a population-based data analysis in the clinical cancer registry of Brandenburg-Berlin

Abstract

Purpose: Stereotactic body radiotherapy (SBRT) is an established treatment method with favorable toxicity for inoperable early-stage non-small-cell lung cancer (NSCLC) patients. This paper aims to evaluate the importance of SBRT in the treatment of early-stage lung cancer patients compared to surgery as standard of care. Methods: The German clinical cancer register of Berlin-Brandenburg was assessed. Cases of lung cancer were considered if they had a TNM stage (clinical or pathological) of T1-T2a and N0/x and M0/x, corresponding to UICC stages I and II. In our analyses, cases diagnosed between 2000 and 2015 were included. We adjusted our models with propensity score matching. We compared patients treated with SBRT or surgery regarding age, Karnofsky performance status (KPS), sex, histological grade, and TNM classification. Further, we assessed the association of cancer-related parameters with mortality; hazard ratios (HR) from Cox proportional hazards models were computed. Results: A total of 558 patients with UICC stages I and II NSCLC were analyzed. In univariate survival models, we found similar survival rates in patients who underwent radiotherapy compared with surgery (HR 1.2, 95% confidence interval [CI] 0.92–1.56; p = 0.2). Our univariate subgroup analyses of patients > 75 years showed a statistically nonsignificant survival benefit for patients treated with SBRT (HR 0.86, 95% CI 0.54–1.35; p = 0.5). Likewise, in our T1 subanalysis, survival rates were similar between the two treatment groups regarding overall survival (HR 1.12, 95% CI 0.57–2.19; p = 0.7). The availability of histological data might be slightly beneficial in terms of survival (HR 0.89, 95% CI 0.68–1.15; p = 0.4). This effect was also not significant. Regarding the availability of histological status in our subgroup analyses of elderly patients, we could show similar survival rates as well (HR 0.70, 95% CI 0.44–1.23; p = 0.14). T1-staged patients also had a statistically nonsignificant survival benefit if histological grading was available (HR 0.75, 95% CI 0.39–1.44; p = 0.4). Concerning adjusted covariates, better KPS scores were associated with better survival in our matched univariate Cox regression models. Further, higher histological grades and TNM stages were related to a higher mortality risk. Conclusion: Using population-based data, we observed an almost equal survival of patients treated with SBRT compared to surgery in stage I and II lung cancer. The availability of histological status might not be decisive in treatment planning. SBRT is comparable to surgery in terms of survival.