Effects of postoperative radiotherapy on cardiovascular-pulmonary disease mortality in patients with stage IIIA-N2 resected NSCLC: analysis of the SEER database

BACKGROUND: The role of postoperative radiotherapy (PORT) in cardiovascular-pulmonary disease mortality in patients with stage IIIA-N2 resected non-small cell lung cancer (NSCLC) remains uncertain. The purpose of this population-based analysis was to explore the effect of PORT on cardiovascular-pulmonary disease mortality in these patients. METHODS: Patients aged ≥ 18 years with stage IIIA-N2 resected NSCLC were identified in the Surveillance, Epidemiology, and End Results (SEER) database from 2004 to 2015 and were grouped according to the use of PORT. Propensity score matching (PSM) was used to account for differences in baseline characteristics between the Non-PORT and PORT groups. The cumulative risk for cardiovascular-pulmonary disease death was estimated using the cumulative incidence curve. Competing risk regression was used to run univariate and multivariate analyses to evaluate risk factors. RESULTS: A total of 3981 patients were included in the study population. Among them, 1446 patients received PORT, and 2535 did not. A total of 1380 patients remained in each group after PSM, and the baseline characteristics were not significantly different between the two groups. The cumulative incidence of cardiovascular-pulmonary mortality was 10.93% in the Non-PORT group compared with 9.85% in the PORT group. There was no significant difference in the cumulative risk between the two groups (HR 1.07, 95% CI 0.77–1.48, p = 0.703). Multivariate analysis indicated that PORT had no significant impact on increased risk, with an HR of 1.18 (p = 0.377). CONCLUSIONS: No significant differences between the PORT and Non-PORT groups were found in cardiovascular-pulmonary-specific modalities in this study. Further studies are required to validate these results. This study highlights the importance of long-term surveillance for NSCLC patients.