Therapeutic outcomes in non-small cell lung cancer with BRAF mutations: a single institution, retrospective cohort study

Background: Data describing therapeutic outcomes in patients with non-small cell lung cancers (NSCLC) with BRAF mutations remains limited.

Methods: We conducted a retrospective cohort study of 31 patients with metastatic NSCLC treated at Duke University Hospital who had been identified by next-generation sequencing methods to bear a BRAF mutation in their tumor in order to evaluate clinical response to immunotherapy and chemotherapy.

Results: Sixty-five percent of patients identified in this cohort were current or former smokers. Fourteen (45.2%) of patients had a BRAF V600E mutation and 17 (54.8%) had a non-V600E mutation. Median progression-free survival (PFS) in the 23 patients who received first-line chemotherapy was 6.4 months [95% confidence interval (CI), 2.3 to 13.0]. Overall survival (OS) in patients who received first-line chemotherapy showed a median survival of 18 months (95% CI, 7.4 to 28.6). OS comparing patients who had never received immunotherapy at any point was 18.4 months (95% CI, 4.1 to NE) compared to 19.0 months (95% CI, 9.9 to 28.6) in those who had received immunotherapy. We did not find a statistically significant difference in OS in patients with BRAF V600E, BRAF amplification, or non-V600E mutations. There was also no difference in OS in patients treated with targeted BRAF inhibitors compared to those who were not treated with targeted BRAF inhibitors.

Conclusions: We describe therapeutic outcomes for patients with metastatic NSCLC with BRAF mutations treated with either cytotoxic chemotherapy or immunotherapy. Although the sample size is small, the survival curves do not suggest improved clinical activity in this population when treated with immunotherapy.