Purpose: Thoracic radiotherapy (TRT) is the recommended therapeutic regimen for extensive-stage small cell lung cancer (ES-SCLC). Little is known about TRT benefits in elderly populations. The aim of this study was to evaluate TRT effects on the prognosis of elderly patients with ES-SCLC.
Patients and methods: This retrospective analysis reviewed the records of patients over 65 years of age with metastatic ES-SCLC treated between 2010 and 2016. Enrolled patients received standard chemotherapy regimens (etoposide plus cisplatin or carboplatin). A total of 93 eligible patients were subjected to propensity score matching, which led to 40 patients being assigned to the TRT group and 40 to the no thoracic radiotherapy (noTRT) group. The cohort of 80 patients (67 males) had the median age of 69 years (range, 65–85 years), with a median of 4 chemotherapy cycle (range, 1–8 cycles), and a median chest irradiation dose of 50 Gy (range, 30–60 Gy). We analyzed overall survival (OS), progression-free survival (PFS), and local recurrence-free survival (LRFS) as endpoints; survival rates were determined by the Kaplan–Meier method and compared across groups with log-rank tests. Multivariate prognostic analysis was performed with Cox regression modeling, and categorical variables were analyzed with Chi-square tests.
Results: In all patients, the 1-year OS, PFS, and LRFS rates were 38.3%, 16%, and 17.9%, respectively. The TRT group had superior survival outcomes compared to the noTRT group: their 1-year OS, PFS, and LRFS rates were 55% vs. 25% (P  < 0.001), 32.1% vs. 0% (P  < 0.001), and 31% vs. 2.6% (P  < 0.001), respectively. TRT did not increase the incidence of adverse reactions (P  = 0.431).
Conclusion: TRT can improve chest tumor control and survival time in elderly ES-SCLC patients. Large-scale studies to further assess the benefits of TRT are warranted.
Keywords: chemotherapy, radiotherapy, prognosis, elderly, small cell lung cancer