Presence of On-Target Resistant Mutation in Pre-Treatment Samples of ALK Fusion Gene Positive Lung Cancer Patients

By using the highly sensitive ddPCR approach, we detected minor clones with on-target resistant mutations in both treatment-naive and relapse biopsies from ALK-positive NSCLC patients. The predictive value of these mutations as the potential resistance-causing mechanism was limited to relapses occurring at the same tumor location as the pre-treatment sample.