The role of adjuvant chemotherapy (CT) for early stage resectable node negative small cell lung cancer with size of <= 2 cm post-surgical resection: A SEER plus based statistical analysis.

e20643 Background: Small cell lung cancer (SCLC) is a poorly differentiated neuroendocrine tumor accounting for 15% of all lung cancers. Surgical resection followed by adjuvant platinum-etoposide is recommended for patients with limited-stage SCLC (T1 N0M0). In this study, we sought to evaluate the survival benefit of adjuvant chemotherapy for patients with ≤2 cm size SCLC following surgical resection. Methods: We utilized Surveillance, Epidemiology and End Results (SEER) plus 18 registries to identify adult patients (≥18 years) diagnosed with small cell cancer of the lung with tumor size of ≤ 2 cm from 2010 to 2018. The study population comprised of patients who underwent surgical resection followed by adjuvant chemotherapy and patients who received surgical resection alone. Kaplan-Meier and long rank tests were used to compare overall survival between the two groups. Multivariate survival analysis was done using the Cox proportional hazards regression model. Results: 419 patients were identified, with 203 (48%) receiving adjuvant CT while 216 (52%) not receiving adjuvant CT. The population who received adjuvant chemotherapy was younger than those who did not (Median years: 67 years vs 71 years, p < 0.001). The 5-year overall survival rate was significantly higher for those receiving adjuvant CT (49% vs 40.9%, P value < 0.001). On multivariate analysis after adjusting for age, gender, race, and origin, adjuvant chemotherapy was associated with better overall survival (HR:0.67; 95% CI 0.54 - 0.88, p = 0.003). Conclusions: Our study demonstrates that adjuvant CT should be used for early-stage small cell lung cancer irrespective of tumor size following surgical resection.