Survival outcomes in locally advanced inoperable NSCLC patients converted to resectable disease by neoadjuvant therapy.

e20075 Background: Locally advanced NSCLC poses a significant therapeutic challenge due to its heterogeneity. NACT, while increasingly employed to convert inoperable disease to operable, requires careful patient selection and assessment of response. This study evaluates the survival outcomes of patients with locally advanced NSCLC rendered resectable by NACT. Methods: We retrospectively reviewed data from patients with initially inoperable locally advanced NSCLC who were treated at our center between Jan 2003 and Dec 2023, and who underwent R0 surgical resection after NACT. Demographic, clinical, radiological, and pathological characteristics, treatment details, and survival outcomes were collected. Factors associated with event-free survival (EFS) and overall survival (OS) were analyzed. Results: Thirty-five patients (86% male; mean age 67.6±8.0 years) were included. Staging at diagnosis was IIB (n=1), IIIA (n=11), IIIB (n=19), and IIIC (n=4). Histology was squamous cell carcinoma (80%) and adenocarcinoma (20%). Patients received a median of 3 (range 2-6) NACT cycles (77% carboplatin and paclitaxel). Postop pathology revealed mediastinal LN involvement (37%), pleural contact/invasion (34.3%), lymphovascular space invasion (LVSI) (25.7%), and cartilage invasion (5.7%). Adjuvant treatment (56% carboplatin and paclitaxel) was administered to 51.4% of patients, with no factor significantly associated with this decision. During a median follow-up of 40.6 months (95% CI: 29-52.2), 13 (37.1%) patients experienced recurrence and 14 (40%) died. The 2-year EFS and OS rates were 53.9±8.9% and 66.3±8.4%, respectively. Median EFS was 15.7 months (95% CI: 0-56.1); median OS was not reached. Conversion to operable status after ≥3 neoadjuvant cycles, postoperative mediastinal LN involvement, and LVSI were associated with worse EFS and OS (Table 1). Conclusions: Neoadjuvant therapy offers long-term survival potential for select patients with locally advanced NSCLC. However, requiring ≥3 cycles for resectability, as well as the presence of postoperative mediastinal LN involvement and LVSI, are associated with poorer outcomes. These factors may help identify patients who could benefit from more aggressive treatment strategies or closer surveillance. Treatment strategies will need to be reconsidered after the immunotherapy era. Factors associated with event-free and overall survival. Factors 2-year EFS p 2-year OS p NACT <3 vs. ≥3 85,7±13,2 vs. 43,8±10,2 0,012 100,0±0,0 vs. 55,7±10,1 0,041 Postoperative mediastinal LN involvement absent vs. present 67,6±10,1 vs. 27,1±14,8 0,013 81,6±8,3 vs. 36,3±15,4 0,017 LVSI absent vs. present 65,4±9,3 vs. 15,6±14,2 0,015 76,7±8,3 vs. 31,1±17,9 0,071 *Survival rates are expressed as percentages with corresponding standard errors, and the P values were calculated using the Log-rank test.