Stereotactic ablative radiotherapy as single treatment for early stage non‐small cell lung cancer: A single institution analysis

BACKGROUND: Stereotactic ablative radiotherapy (SABR) is the current standard‐of‐care in cases of inoperable early stage non‐small cell lung cancer (ES‐NSCLC). This study aimed to assess the survival outcomes and recurrence patterns after SABR for ES‐NSCLC in a hospital setting. METHODS: A single‐institution retrospective study was performed which included 109 patients who had undergone SABR. The main study endpoints were overall survival (OS), cancer specific survival (CSS), local recurrence‐free survival (LRFS), regional recurrence free survival (RRFS) and distant metastasis‐free survival (DMFS). Univariate and multivariate analysis were conducted to explore the potential factors which might be related to patient survival. RESULTS: A total of 109 patients were enrolled into the study. Median follow‐up was 44 months (range: 2–93 months). (i) Recurrence results: Among 45 patients with recurrence, 30 patients (28%) had distant metastasis (DM), 17 patients (16%) had local recurrence (LR), 10 patients (9%) had regional recurrence (RR) of lymph nodes and two patients (2%) had second primary lung cancer (SPLC). (ii) Survival results: Median OS, CSS, PFS was 78 months, 78 and 40 months. Two‐year OS, CSS, PFS, LRFS, RRFS and DMFS was 84.7%, 87.1%, 69.2%, 86.8%, 92.7% and 78.0%, respectively. Four‐year OS, CSS, PFS, LRFS, RRFS and DMFS was 55.6%, 60.7%, 37.3%, 76.3%, 88.4% and 59.4%, respectively. (iii) Univariate and multivariate analyses indicated that age was a prognostic factor of CSS in patients aged <75 years (P = 0.04 HR 2.12 95% confidence interval [CI]: 1.04–4.33). CONCLUSIONS: Although high survival rates can be achieved in ES‐NSCLC patients treated with SABR, using SABR on its own may not be enough. Prolonged surveillance and adjuvant therapy is therefore needed.