Comparison of treatment outcomes between stereotactic body radiotherapy/proton beam therapy and sublobar resection for vulnerable elderly patients with stage IA non-small cell lung cancer

Objective The aim of this study was to compare survival and the incidence of complications between stereotactic body radiotherapy/proton beam therapy (SBRT/PBT) and sublobar resection for vulnerable elderly patients with clinical stage IA non-small cell lung cancer (NSCLC). Methods We included patients aged ≥75 years who underwent sublobar resection without mediastinal lymph node dissection or SBRT/PBT for solid predominant clinical stage IA non-small cell lung cancer measuring ≤3 cm in total size. Propensity score matching was used to reduce the selection bias. Complication and survival rates were compared between groups. Results Of the 119 included patients, 86 received stereotactic body radiotherapy (62 received X-ray radiotherapy and 24 received proton beam therapy), while 33 received sublobar resection (11 received segmentectomy and 22 received wedge resection). The SBRT/PBT group included significantly older patients (median: 82 vs. 79 years) and larger tumors (median: 18 vs. 16 mm) than did the surgery group. After propensity score matching, 24 patients were analysed in each group. The incidence of ≥Grade 2 complications was not significantly different between the two groups (12.5% vs. 29.1%; OR = 0.35, 95% CI: 0.08–1.55; P = 0.286). Moreover, there were no significant differences in overall and recurrence-free survival rates (OS: HR = 0.68; 95% CI: 0.31–1.50; P= 0.343; RFS: HR = 0.69; 95% CI: 0.33–1.46; P = 0.336, respectively) and the cumulative incidence of recurrence (sHR = 0.87; 95% CI: 0.31–2.40; P = 0.781). Conclusions For vulnerable elderly patients with NSCLC, SBRT/PBT may be comparable with sublobar resection in terms of patient survival and safety. Prospective randomized controlled trials are required to confirm these findings.