Factors Associated With Survival in Complete Pathologic Response Non–Small Cell Lung Cancer

Abstract

ObjectivesThere is a strong association with improved survival for patients with non–small cell lung cancer (NSCLC) who have developed a pathological complete response (pCR) after neoadjuvant therapy. A national database was used to investigate factors associated with long-term survival in this cohort of patients. PatientsRetrospective review was completed of the National Cancer Database of patients who obtained pCR and had neoadjuvant therapy for stage I to stage III NSCLC between 2004 and 2014. All patients had neoadjuvant chemotherapy with or without radiation therapy. MethodsUnivariate and multivariable analysis was performed on factors associated with overall survival (OS), including gender, clinical stage, and nodal count. Patients were divided into 2 groups based on the Commission on Cancer–recommended median number of lymph nodes (LNs) examined: 0 to 9 LNs and ≥10 LNs. Chi-square and Wilcoxon rank-sum tests were used to compare patient, hospital, and clinical variables between groups. ResultsIncreased age (hazard ratio [HR] 1.02, 95% confidence interval [CI], 1.00-1.03), neoadjuvant radiation therapy (HR 1.48, 95% CI, 1.10-2.00), and pneumonectomy (HR 1.64, 95% CI, 1.22-2.22) were associated with worse survival in the 759-patient cohort. Multivariable regression demonstrated having ≥10 nodes harvested (HR 0.71, 95% CI, 0.56-0.89) was associated with improved survival as was every increase in LN harvest up to 17 LNs. No significant differences in 5-year OS were found between clinical stage I, II, and III, respectively (66.1% vs. 60.9% vs. 58.6%, P = .288). ConclusionThis study shows that younger age, increasing LN harvest, female sex, the absence of neoadjuvant radiation therapy and non-pneumonectomy resections are all associated with improved OS in patients with NSCLC who have developed pCR.