Benefit of adjuvant chemotherapy for resected pathologic N1 non-small cell lung cancer is unrecognized: A subgroup analysis of the JBR10 trial

Abstract

Adjuvant chemotherapy is underutilized in clinical practice, in part, because its anticipated survival benefit is limited. We evaluated the impact of AC on overall and recurrence-free survival among completely resected pN1 NSCLC patients enrolled in the North American Intergroup phase III (JBR10) trial. A post-hoc subgroup analysis of pN1 NSCLC patients was performed. Participants were randomized to cisplatin+vinorelbine (AC) (n = 118) or observation (n = 116) following complete resection. The primary endpoint was overall survival (OS). The secondary endpoint was recurrence free survival (RFS). Kaplan-Meier methods were used to compare OS and RFS between the two treatment groups. Cox regression was used to identify factors associated with OS and RFS endpoints. Both groups had similar baseline characteristics. AC patients had improved 5-year OS (AC 61.4% vs observation 41.0%, log-rank p = .008) and 5-year RFS (AC 56.2% vs observation 39.9%, log-rank p = .011) rates compared to observation. Cox regression analyses confirmed the OS (HR 0.583, 95% CI 0.402-0.846, p = .005) and RFS (HR 0.573, 95% CI 0.395-0.830, p = .003) benefit associated with AC. AC was associated with a lower risk (HR 0.648, 95% CI 0.435-0.965, p = .0326) and a lower cumulative incidence (Subdistribution Hazard Ratio [SHR], 0.67, 95% CI 0.449-0.999, p = .0498) of lung cancer deaths. In the JBR10 trial, treatment with AC conferred a significant OS and RFS advantage over observation for pN1 NSCLC patients. These data suggest that pN1 NSCLC patients may experience a disproportionately greater clinical benefit from AC than the 6% survival advantage estimated by the LACE meta-analysis.