128P Stereotactic ablative radiotherapy in locally-advanced non-small cell lung cancer patients: Little palliation or big cure? Sub-analysis of START-NEW-ERA phase II trial

Early analysis1 of a single arm phase II trial assessed local control (LC) and safety of stereotactic ablative radiotherapy (SAbR) unresectable locally advanced non-small cell lung cancer (LA-NSCLC) patients unfit for concurrent chemo-radiotherapy (ChT-RT). Here we report clinical outcomes of LA-NSCLC patients submitted to exclusive SAbR. Between December 31, 2015 and June 30, 2022 71 LA-NSCLC patients were enrolled. 40 (56%) and 31 (44%) received neoadjuvant ChT+SAbR and exclusive SAbR, respectively. The tumor volume included primary tumor (T) and any regionally positive node/s (N). The co-primary study endpoints were LC and safety. The median age was 80 years (range, 45–88). Twenty (64%) and eleven (36%) patients had PS 0–1 and 2, respectively. Histology was adenocarcinoma (ADC) and squamous cell carcinoma (SCC) in 71% and 29%, respectively. 27 (87%) patients had ultra-central tumor. Median prescribed dose was 45 Gy (range, 35–55) and 40 Gy (35–45) in 5 daily fractions to T and N, respectively. After a median follow-up of 27 months (range, 6–92), 9 (29%) patients had experienced local recurrence (LR) at a median time of 13 months (range, 7–34). The median LR-free survival (FS) was not reached (95% CI, 28 to not reached). The 1-, 2- and 4- year LR-FS rates were 81 ± 7%, 66 ± 9% and 66 ± 9%, respectively. At last follow-up, 23 (74%) patients were alive. Median overall survival (OS) was not reached. The 1, 2, and 4-year OS rates were 97 ± 3%, 74 ± 8% and 70 ± 9%, respectively. Eight (26%) patients developed distant progression (dP). The median dP-FS was not reached (95% CI, 26 to not reached). The 1, 2, and 4-year dP-FS rates were 82 ± 7%, 72 ± 9% and 66 ± 10%, respectively. LA-NSCLC patients treated with exclusive SAbR had optimal local control and promising overall survival with excellent treatment compliance and absence of ≥G3 toxicity. Our preliminary prospective clinical outcomes provide an attraction to evaluate this approach in patients unfit to ChT, to obtain a “big” cure beyond “little” palliation. 1 Int J Radiat Oncol Biol Phys. 2022 Oct 24;S0360–3016(22)03459–9. doi: 10.1016/j.ijrobp.2022.10.025.