BRAF mutational status is associated with survival outcomes in locally advanced resectable and metastatic NSCLC

Background: Immunotherapy-based treatments have demonstrated high efficacy in patients with advanced and locally advanced non-small-cell lung cancer (NSCLC). BRAF mutations affect a small but significant fraction of NSCLC. The efficacy of these therapies in this subgroup of patients is unknown. Materials and methods: Plasma and tissue samples from 116 resectable stage IIIA/B NSCLC patients, included in NADIM and NADIM II clinical trials (NADIM cohort), and from a prospective academic cohort with 84 stage IV NSCLC patients (BLI-O cohort), were analyzed by next-generation sequencing. Results: The p.G464E, p.G466R, p.G466V, p.G469V, p.L597Q, p.T599I, p.V600E (n = 2) BRAF mutations, were identified in four (3.45 %) samples from the NADIM cohort, all of which were cases treated with neoadjuvant chemoimmunotherapy (CH-IO), and four (4.76 %) samples from the BLI-O cohort, corresponding to cases treated with first-line immunotherapy (n = 2) or CH-IO (n = 2). All these patients were alive and had no evidence of disease at data cut-off. Conversely, patients with BRAF wild-type (wt) tumors in the BLI-O cohort had a median progression-free survival (PFS) of 5.49 months and a median overall survival (OS) of 12.00 months (P-LogRank = 0.013 and 0.046, respectively). Likewise, PFS and OS probabilities at 36 months were 60.5 % and 76.1 % for patients with BRAF-wt tumors in the NADIM cohort. The pathological complete response (pCR) rate after neoadjuvant CH-IO in patients with BRAF-positive tumors (n = 4) was 100 %, whereas the pCR rate in the BRAF-wt population was 44.3 % (RR: 2.26; 95 % CI: 1.78-2.85; P < 0.001). Conclusion: BRAF mutations may be a good prognostic factor for advanced and locally advanced NSCLC patients undergoing immunotherapy-based treatments.