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.