A Multicenter Study to Assess EGFR Mutational Status in Plasma: Focus on an Optimized Workflow for Liquid Biopsy in a Clinical Setting

A multicenter study was performed to determine an optimal workflow for liquid biopsy in a clinical setting. In total, 549 plasma samples from 234 non-small cell lung cancer (NSCLC) patients were collected. Epidermal Growth Factor Receptor (EGFR) circulating cell-free tumor DNA (ctDNA) mutational analysis was performed using digital droplet PCR (ddPCR). The influence of (pre-) analytical variables on ctDNA analysis was investigated. Sensitivity of ctDNA analysis was influenced by an interplay between increased plasma volume (p < 0.001) and short transit time (p = 0.018). Multistep, high-speed centrifugation both increased plasma generation (p < 0.001) and reduced genomic DNA (gDNA) contamination. Longer transit time increased the risk of hemolysis (p < 0.001) and low temperatures were shown to have a negative effect. Metastatic sites were found to be strongly associated with ctDNA detection (p < 0.001), as well as allele frequency (p = 0.034). Activating mutations were detected in a higher concentration and allele frequency compared to the T790M mutation (p = 0.003, and p = 0.002, respectively). Optimization of (pre-) analytical variables is key to successful ctDNA analysis. Sufficient plasma volumes without hemolysis or gDNA contamination can be achieved by using multistep, high-speed centrifugation, coupled with short transit time and temperature regulation. Metastatic site location influenced ctDNA detection. Finally, ctDNA levels might have further value in detecting resistance mechanisms

Does nivolumab for progressed metastatic lung cancer fulfill its promises? : an efficacy and safety analysis in 20 general hospitals

Objectives: In patients with refractory or recurrent non-small-cell lung cancer (NSCLC) after first line chemotherapy, phase III trials showed superiority of nivolumab, an IgG4 programmed death-1 immune-checkpoint inhibitor antibody, over docetaxel. We evaluated case mix, effectiveness and safety of nivolumab upon implementation in general practice. Materials and methods: In 20 general hospitals, all consecutive NSCLC patients treated with nivolumab within the medical need program (inclusion period 12 months) in Flanders - Belgium were evaluated. Results: There were 267 patients, Eastem Cooperative Oncology Group (ECOG) score was 2 in 24% and 0-1 in 76%. In 48%, two or more systemic regimens were given before nivolumab. The median overall survival was 7.8 months (95% confidence interval (CI) 6.3-9.3). At one year, the overall survival rate was 36.5 +/- 0.34%. Median progression-free survival was 3.7 months (95% CI 2.9-4.5). An objective response was obtained in 23.2%. ECOG score 2 and presence of liver metastasis strongly correlated with worse survival (p < 0.00001). Treatment related adverse events grade 3 or 4 were reported in 21%, colitis (4%) and pneumonitis (7%) were most frequent. Conclusion: Upon implementation of nivolumab therapy in general hospitals, the case mix was characterized by a more heavily pretreated population with a substantial fraction of patients with ECOG score 2. The median overall survival is slightly inferior to what was published in the randomized phase III trials. An ECOG score 2 and the presence of liver metastasis correlated strongly with a worse survival. We report a high prevalence of serious adverse events