Abstract 129P
Background
The recommended treatment for T3 non-small cell lung cancer (NSCLC) presenting with separate tumor nodule(s) in the same lobe as the primary (“T3-Add”) includes surgical resection followed by adjuvant chemotherapy. This study sought to assess long-term survival of patients receiving adjuvant chemotherapy for T3-Add tumors across different tumor histologies.
Methods
Patients with T3-Add, N0-2, M0 NSCLC, after restaging based on AJCC 8th Edition TNM staging guidelines, in the National Cancer Database (NCDB) from 2010 to 2015 who underwent lobectomy with complete (R0) resection, without neoadjuvant therapy were included. Long-term overall survival was evaluated stratified by adjuvant chemotherapy status and histology (lung adenocarcinoma vs lung squamous cell carcinoma), using Kaplan-Meier analysis, Cox proportional hazards modeling, and propensity score matching on 11 common prognostic variables including comorbidities and clinical N status.
Results
Of the 2,069 patients with T3-Add tumors who satisfied the study's inclusion criteria, 842 (40.7%) received adjuvant chemotherapy. Lung squamous cell histology was associated with significantly worse overall survival than lung adenocarcinoma histology (HR: 1.30, 95% CI: 1.09–1.56, p = 0.003). 41.7% (677/1,624) patients with adenocarcinoma and 37.1% (165/445) patients with squamous cell carcinoma received adjuvant chemotherapy. Individual propensity score-matched analyses stratified by histology were conducted comparing patients that did or did not receive adjuvant therapy. In the adenocarcinoma cohort (466 in each arm), use of adjuvant chemotherapy was not significantly associated with overall survival (66.3% [95% CI: 61.2–70.9] vs 63.8% [95% CI: 58.6–68.5], p = 0.24). However, for patients with lung squamous cell carcinoma (100 in each arm), adjuvant chemotherapy was associated with better 5-year overall survival (56.9% [95% CI: 44.0–67.8] vs 45.1% [95% CI: 33.5–56.1]).
Conclusions
The results of this national analysis support current guidelines that recommend adjuvant chemotherapy following surgery for T3 NSCLC presenting as a primary tumor with additional intrapulmonary nodule(s) in the same lobe for lung squamous cell carcinoma but not for lung adenocarcinoma.
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.