Surgical resection is the standard curative treatment for stage I non-small cell lung cancer (NSCLC), whereas stereotactic body radiotherapy (SBRT) is an established alternative for patients who are medically inoperable or decline surgery. However, comparative long-term oncologic outcomes remain debated. This study compared outcomes of surgery and SBRT in patients with clinical stage I NSCLC.

This retrospective two-center cohort study included 157 patients treated between 2010 and 2022 (93 surgery, 64 SBRT). The surgical cohort included a substantial proportion of thoracotomy procedures, reflecting routine clinical practice. Overall survival (OS), disease-free survival (DFS), local control (LC), and locoregional control (LRC) were estimated using Kaplan–Meier analysis. Multivariable Cox regression was used to adjust for baseline differences. Because histological confirmation was unavailable in a subset of SBRT patients, a sensitivity analysis restricted to histologically confirmed NSCLC cases (n = 143) was performed.

Median follow-up was 57 months in the surgical group and 48 months in the SBRT group. Median OS, DFS, LC, and LRC numerically favored surgery, although no statistically significant differences were observed (p > 0.05). Five-year OS was 58% after surgery and 49% after SBRT. The SBRT cohort had a higher burden of comorbidities (93% vs. 56%). Distant metastasis occurred more frequently after SBRT (28.1% vs. 15.1%, p = 0.006). Sensitivity analysis of histologically confirmed cases yielded results consistent with the primary analysis.

Surgical resection and SBRT demonstrated comparable oncologic outcomes in this real-world cohort of stage I NSCLC. SBRT remains an effective option for medically inoperable patients, whereas surgery offers the advantage of pathological staging in eligible individuals. Consistent findings in the histologically confirmed cohort support the robustness of these results. Prospective randomized trials are needed to further define optimal management.

Not applicable.