Study of non-surgical therapeutic patterns and prognosis in elderly patients with stage II non-small-cell lung cancer: an investigational study based on the SEER database.

Background: While surgery remains the standard of care for stage II non-small-cell lung cancer (NSCLC) for most patients, numerous older patients are non-surgical candidates because of either frailty or comorbidities. We aim to assess the comparative effectiveness of chemoradiotherapy (CRT) compared to radiotherapy (RT) for older patients with stage II NSCLC using data from the Surveillance, Epidemiology, and End Results (SEER) database and propensity score matching (PSM) methods. Surgery remains the approved standard of care for stage II NSCLC. But for older populations, those aged 65 years or older, they often may not undergo surgery for a variety of reasons. Methods: We selected 2,646 patients ≥65 years of age with stage II NSCLC from the SEER database. Patients were divided into CRT and RT groups. PSM was completed with demographic and clinical variables, including age, sex, tumor stage, histology, and primary site. We used Kaplan-Meier (KM) survival analysis and multivariable Cox proportional hazards models to analyze overall survival (OS) and cancer-specific survival (CSS). Results: Before PSM, the 3- and 5-year OS rates in the CRT group were 29.3% and 16.8% vs. 23.4% and 11.2% in the RT group (P<0.001). The CSS rates were 35.3% and 25.0% in the CRT group compared with 33.3% and 22.4% in the RT group (P=0.02). After PSM, CRT demonstrated better OS and CSS measures vs. RT. After PSM, multivariable Cox regression found that patients receiving CRT had significantly better OS and CSS vs. patients receiving RT [OS, hazard ratio (HR) =0.8, 95% confidence interval (CI): 0.73-0.87; CSS, HR =0.89, 95% CI: 0.8-0.98]. After PSM, CRT was associated with superior OS (HR =0.79, 95% CI: 0.71-0.88) and CSS (HR =0.87, 95% CI: 0.77-0.97). Conclusions: In summary, CRT was associated with improved OS and CSS in non-surgical stage II NSCLC patients aged 65 years or older.