Stage IIIA Non-Small Cell Lung Cancer Treatment and Outcomes: A Single Institution Retrospective Analysis

Abstract

Treatment of locally advanced non-small cell lung cancer (NSCLC) remains challenging, with a multitude of treatment options available for Stage III patients. We hypothesized that Stage IIIA outcomes differ by treatment received. We performed a retrospective review of NSCLC patients ≥18 years old with Stage IIIA disease treated 1/1/2010-03/01/2022. Demographics, treatment received, treatment outcomes, and failure patterns were collected. Progression-free survival (PFS) and overall survival (OS) were assessed using Kaplan-Meier analysis. Kruskal-Wallis ANOVA was used to compare groups. Of 352 patients identified, 160 had Stage IIIA NSCLC with a median follow-up of 29.1 months. Patients had a median age of 63 years, 79 (49.4%) were male, and 137 (85.6%) were current/former smokers (with 30 median pack-years). Patients were treated as follows: 17 (11%) surgery alone (S), 91 (57%) definitive radiation ± chemotherapy (CRT), 52 (33%) neoadjuvant therapy followed by surgery (Neo). 6 (12%) of the Neo group received chemoimmunotherapy, and 21 (51%) of the 41 CRT patients received adjuvant immunotherapy. Between the three groups, there were no significant differences in tumor size as measured by T-staging (p = 0.83) and baseline FEV1/FVC (p = 0.92). Median PFS was 33.5mo (95% CI 13.2-NA) for group S, 18.4mo (95% CI 12.7-42.2) for CRT, and 19.7mo (95% CI 13.9-NA) for Neo with no significant intergroup difference (p = 0.72). Median OS was 33.5mo (95% CI 13.2-NA) for S, 48.7mo (95% CI 36.0-88.9) for CRT, and 50.9mo (95% CI 41.9-NA) for Neo with no significant intergroup difference (p = 0.94). Among the 17 primary surgical patients, 11 (65%) experienced failure: 6 (35%) local, 5 (29%) regional, and 7 (41%) distant. Among the 91 CRT patients, 57 (63%) experienced failure: 40 (44%) local, 35 (38%) regional, and 28 (31%) distant. Among the 52 Neo patients, 26 (50%) experienced failure: 14 (27%) local, 15 (29%) regional, and 17 (33%) distant. There were no significant differences in rates of local failure (p = 0.26), regional failure (p = 0.59), distant failure (p = 0.79), or any failure (p = 0.41) among the three treatment groups. The most common locations for distant failure were pleural effusions (n = 15, 29%), CNS (n = 14, 27%), and bone (n = 11, 21%). In this single institution retrospective study, we find no significant differences in PFS, OS, and failure patterns between patients with Stage IIIA NSCLC treated with definitive (chemo)radiation and neoadjuvant therapy. Numeric improvement in PFS in surgery-only patients is consistent with expected patient selection of this group. Further work in the immunotherapy era is needed.