Real world characteristics of stages II-III NSCLC patients (pts) who initiate neoadjuvant chemo-immunotherapy (NACT-I) and do not undergo surgical resection.

8019 Background: Neoadjuvant and perioperative chemo-immunotherapy studies report 15%-20% of pts initiating NACT-I do not undergo surgical resection. Methods: Real-world data of pts who initiated NACT-I was collected retrospectively for January 1 st 2022 till September 30 th 2024. Pts and treatment details, reason for not undergoing resection (as assessed by the clinicians) and later treatments and outcomes were recorded. Total number of pts who initiated NACT-I in this period was identified from each center's records. Missing data was not imputed. Results: Data was collected from 10 centers in 4 countries (USA, Israel, Switzerland, France). Out of 330 pts that started NACT-I 43 pts (13%; range 4-33% in different centers) did not undergo surgical resection. Of these 43 pts, 34.9% became unresectable due to disease progression (PD). 20.9% in retrospect were non-resectable and did not regress as expected. 11.6% in retrospect were non-operable. 11.6% suffered toxicity and became unfit for surgery. 7% of pts refused surgery, 14% were not resected for other reasons (Table). Of the non-resected pts, 9.3% died prior to any second-line treatment. As a second line, 44.2% of the non-resected pts were treated with chemo-radiation, 14% with radiation alone, 7% chemotherapy and immunotherapy, 4.7% immunotherapy alone and 2.3% chemotherapy alone. 7% received palliative radiation followed by chemo or immunotherapy, 7% had follow-up alone. Conclusions: The rate of no surgical resection in this real-world multi-national cohort was 13%, in line with the rate in reported studies. Most un-resected pts underwent appropriate staging. Most were male, with high rate of T3/T4. Survival rate at 12 months was 73.7%. The most common causes for no surgery were PD or being upfront unresectable. The patients with the worst outcome were those who experienced PD during NACT-I. N (% out of 43 non-resected) Male (%) Age (median) PET Done prior to any therapy (%) Brain MRI staging (%) Documented MDT decision of NACT-I (%) Documented surgeon evaluation prior to NACT-I decision (%) T3-4 (%) N2a/b (9th V TNM; %) Survival rate at 12 month (95% CI) 43 (100.0) 69.8 71 95.3 95.0* 96.6* 86.2* 69.8 40.5 73.7% (50.5-87.2%) PD 15 (34.9) 80.0 67 93.3 100.0* 100.0* 92.3* 80.0 40.0 68.2% (14.2-89.7%) In retrospect not resectable 9 (20.9) 55.6 69 100.0 100.0 100.0* 50.0* 77.8 33.3 76.2% (33.2-93.5%) In retrospect not operable 5 (11.6) 80.0 71 100.0 60.0 100.0* 33.3* 40.0 20.0 100.0% (100.0-100.0%) Toxicity 5 (11.6) 80.0 72 100.0 100.0 100.0* 100.0* 80.0 80.0 80.0% (20.4-96.9%) Patient refusal 3 (7.0) 0.0 72 100.0 100.0 100.0 100.0 66.7 33.3 100% (100.0-100.0%) Other ** 6 (14.0) 83.3 75 83.3 100.0* 75.0* 100.0 50.0 40.0* 50.0% (11.1-80.4%) <jats:fn id="TF-485762-00