Co-occurring MET Amplification Predicts Inferior Clinical Response to First-Line Erlotinib in Advanced Stage EGFR-Mutated NSCLC Patients.

BACKGROUND: Intrinsic resistance is a major obstacle in treatment of non-small cell lung cancer (NSCLC) patients with an activating mutation in the epidermal growth factor receptor (EGFR). We investigated co-occurring genetic alterations in circulating tumor DNA (ctDNA) as predictive markers of clinical response to first-line erlotinib. METHODS: Pretreatment plasma samples were collected from 76 patients with EGFR-mutated, advanced-stage NSCLC treated with first-line erlotinib. We isolated ctDNA from plasma for next-generation sequencing. RESULTS: Co-occurring oncogenic drivers were detected in 21% of pretreatment samples and correlated with decreased progression-free survival (PFS) (6.9 months vs 14.4 months; hazard ratio [HR], 2.088; 95% confidence interval [CI], 0.8119-5.370; P = .0355). Concurrent MET amplification was identified in 9 samples (12%), predicting inferior PFS (5.5 months vs 14.4 months; HR, 4.750; 95% CI, 0.5923-38.10; P = .0007) and overall survival (7.6 months vs 28.3 months; HR, 3.952; 95% CI, 0.8441-18.50; P = .0005). Co-occurring non-MET-amplification oncogenic alterations showed a tendency for shorter PFS (9.9 months vs 14.4 months; HR, 1.199; 95% CI, 0.3373-4.265; P = .7586). Clearing EGFR-mutated ctDNA during erlotinib treatment is a positive predictor of clinical outcomes. Among patients who cleared the EGFR mutation, 12% had a co-occurring oncogenic driver, with a tendency toward inferior PFS (8.7 months vs 16.1 months; HR, 1.703; 95% CI, 0.5347-5.424; P = .2508). CONCLUSION: Co-occurring MET amplification in pretreatment ctDNA samples predict inferior clinical response to first-line erlotinib in advanced-stage, EGFR-mutated NSCLC patients. Co-occurring oncogenic alterations were associated with inferior response and may be potential predictors of clinical outcome.

Clearing of circulating tumour DNA predicts clinical response to first line tyrosine kinase inhibitors in advanced epidermal growth factor receptor mutated non-small cell lung cancer.

OBJECTIVES: Epidermal growth factor receptor (EGFR) mutations confer sensitivity to tyrosine kinase inhibitors (TKIs) in non-small cell lung cancer (NSCLC). However, a subset of patients has limited or no response. We investigated the initial dynamics of EGFR mutations detected in circulating tumour DNA (ctDNA) during treatment as a predictive marker of outcome. METHODS: A total of 225 patients with advanced EGFR mutated NSCLC were included for consecutive blood sampling in this prospective multicentre study. Out of these, 146 patients received first line TKI and had a baseline blood sample available for EGFR mutation testing with the Cobas® EGFR mutation test V2. For examinations on clearing and clinical outcome, 98 patients who had detectable ctDNA at baseline and at least one follow-up blood sample were included. RESULTS: For patients with EGFR mutations present in plasma at baseline, clearing of mutations from the blood during first line TKI served as a positive predictor for objective response rate (p = 0.0008), progression-free survival (PFS) (p < 0.0001) and overall survival (OS) (p < 0.0001). This was seen both for patients who cleared the ctDNA within the first 7 weeks of treatment and patients who cleared the ctDNA at a slower pace. Baseline mutation presence was a negative predictor for PFS (p = 0.0069) and OS (p = 0.0340). CONCLUSION: The current study is the first to confirm, in a sizeable Caucasian cohort, that clearing of EGFR mutations predict outcome to first line TKI in patients with EGFR mutated NSCLC.

Circulating miR-30b and miR-30c predict erlotinib response in EGFR-mutated non-small cell lung cancer patients.

OBJECTIVES: MiR-30b, miR-30c, miR-221 and miR-222 are known to induce gefitinib resistance in lung cancer cell lines with activation of mutations in the epidermal growth factor receptor (EGFR). However, the role of these four microRNAs in tyrosine kinase inhibitor (TKI)-resistance in non-small cell lung cancer (NSCLC) patients is unknown. Thus, the aim of this study was to investigate the predictive value of miR-30b, miR-30c, miR-221 and miR-222 in plasma from EGFR-mutated lung cancer patients receiving erlotinib. MATERIALS AND METHODS: The cohort consisted of 29 EGFR-mutated lung cancer patients receiving erlotinib. Plasma levels of miR-30b, miR-30c, miR-221 and miR-222 were analyzed by qPCR from blood samples collected before treatment start. Plasma concentration of each microRNA was correlated to clinical outcome. RESULTS: Plasma concentrations of miR-30b and miR-30c could be determined in all 29 patients. Low plasma concentrations of miR-30b and miR-30c showed significant correlation with superior progression-free survival (PFS) (miR-30b: HR = 0.303 [0.123-0.747], p < 0.05; miR-30c: HR = 0.264 [0.103-0.674], p < 0.05). Low plasma concentrations of miR-30c were also significantly correlated with superior overall survival (OS) (HR = 0.30 [0.094-0.954], p < 0.041). CONCLUSION: High plasma concentrations of miR-30b and miR-30c predicted shorter PFS and OS. This implies that miR-30b and miR-30c could have clinical potential as biomarkers in EGFR-mutated lung cancer patients.