Genomic Analyses for Predictors of Response to Chemoradiation in Stage III Non-Small Cell Lung Cancer

Radiation with platinum-based chemotherapy is the standard of care for unresectable stage III non-small cell lung cancer (NSCLC). Despite aggressive treatment, progression-free survival and overall survival remain poor. It is unclear whether any tumor genetic mutations are associated with response to chemoradiation therapy.

We retrospectively reviewed clinical outcomes of patients with stage III NSCLC treated with definitive radiation who had undergone tumor molecular profiling through a next-generation DNA sequencing platform. Cox proportional hazards model was used to investigate associations between clinical outcomes and genetic mutations detected by next-generation sequencing.

110 patients were identified with stage III NSCLC and underwent definitive radiation between 2013 and 2017 and tumor molecular profiling. Concurrent or sequential chemotherapy was given in 104 patients (95%). Unbiased genomic analyses revealed a significant association between AKT2 mutations and decreased local-regional tumor control and overall survival (hazard ratios [HR] 12.5 and 13.7, P = .003 and P = .003, respectively). Analyses restricted to loss-of-function mutations identified KMT2C and KMT2D deleterious mutations as negative prognostic factors for overall survival (HR 13.4 and 7.0, P < .001 and P < .001, respectively). Deleterious mutations in a panel of 38 DNA damage response and repair pathway genes were associated with improved local-regional control (HR 0.32, P = .049).

This study coupled multiplexed targeted sequencing with clinical outcome and identified mutations in AKT2, KMT2C, and KMT2D as negative predictors of local-regional control and survival, and deleterious mutations in damage response and repair pathway genes were associated with improved local-regional disease control after chemoradiation therapy. These findings will require validation in a larger cohort of patients with prospectively collected and detailed clinical information.