ESTRO 2024 - Abstract Book

S1826

Clinical - Lung

ESTRO 2024

in early analysis of START-NEW-ERA non randomized phase II trial (1) stereotactic ablative radiotherapy (SAbR) had optimal local control (LC) and promising overall survival (OS) in absence of ≥G3 toxicity. We report 5 -y efficacy and safety outcomes, approximately 3 years after the last enrolled patient.

Material/Methods:

Patients with unresectable locally advanced (LA) non-small cell lung cancer (NSCLC) unfit for concurrent radio chemotherapy (RT-ChT) were enrolled. Neoadjuvant ChT was prescribed in fit patients. The tumor volume included primary tumor (T) and any regionally positive node/s (N). The co-primary study endpoints were LC and safety.

Results:

Between December 31, 2015 and December 31, 2020 50 LA-NSCLC patients were enrolled. Histology was squamous cell carcinoma (SCC) and adenocarcinoma (ADC) in 52% and 48%, respectively. 40 (80%) patients had ultra-central tumor. Twenty-seven (54%) received neoadjuvant ChT and 7 (14%) adjuvant Durvalumab. 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 63 months (range, 12-102), 19 (38%) patients had experienced local recurrence (LR). The median LR-free survival (FS) was not reached (95% CI, 28 to not reached). The 1-, 3- and 5- year LR-FS rates were 86±5%, 59±7% and 59±7%, respectively. At last follow-up, 27 (54%) patients were alive. Median overall survival (OS) was 55 months (95% CI, 43 55 months). The 1, 3, and 5-year OS rates were 94±3%, 70±6% and 50±7%, respectively. The median DFS was 13 months (range, 11-18). The 1, 3, and 5-year disease free survival rates were 56 ±7%, 24±6% and 21±6%, respectively. Only one (2%) patient developed grade (G) 3 toxicity. ADC (HR, 3.61;95% CI, 1.15-11.35) resulted significant predictor of better LC, while OS was significantly conditioned by smaller PTVs (HR, 1.004;95% CI, 1.001-1.010) and TNM stage (HR, 4.8;95% CI, 1.34-17).

Conclusion:

This 5-year update analysis demonstrates robust and sustained clinical outcomes benefit with SAbR in LA-NSCLC patients with only one case of G3 toxicity suggesting the feasibility of using this approach in LA-NSCLC patients unfit for concurrent ChT-RT.

Keywords: Unresectable LA-NSCLC; SAbR; Local control

References:

Int J Radiation Oncol Biol Phys, Vol. 115, No. 4, pp.886-896, 2023

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