Survival of patients with node-negative lung cancer and chest wall invasion

Patients with T3 non-small cell lung cancer (NSCLC) with chest wall invasion (CWI) have poorer survival than patients with T3 NSCLC defined by other T3 descriptors, but their survival has not been compared with patients with T4 NSCLC. Our objective was to compare the survival of patients with NSCLC with CWI, currently a T3 descriptor, with that of patients with T4 NSCLC.

A retrospective analysis was conducted of the National Cancer Database (NCDB) comparing patients diagnosed with node-negative NSCLC <7 cm with CWI to those diagnosed with cT4N0M0 NSCLC from 2010-2015. A 1:1 propensity match was performed. Demographics, comorbidities, and tumor characteristics were compared utilizing chi-squared and Wilcoxon rank-sum tests. Kaplan-Meier analysis was used to estimate 5-year overall survival (OS).

In total, 1,734 matched patients were studied (867 T3 with CWI, 867 T4). There were no significant differences in baseline demographics, tumor characteristics, treatment, or surgical approach used (all P>0.05). There were no significant differences in 30-day (P=0.27) or 90-day (P=0.33) mortality between the two groups. Five-year OS was also similar between the two groups [44.0% T3 with CWI, 95% confidence interval (CI): 41-47% vs. 43.8% T4, 95% CI: 40-47%; P=0.50]. Median survival was 40 months (range 0.2-123 months for the T3 cohort and 0.3-120 months for the T4 cohort).

CWI might serve better as a T4 descriptor in future iterations of the Tumor, Node, Metastasis (TNM) classifications. This would allow providers to better stage and treat patients, which would subsequently affect survival.