Detecting an ALK Rearrangement via Liquid Biopsy Enabled a Targeted Therapy-based Approach for Treating a Patient with Advanced Non-small Cell Lung Cancer

Initial diagnostic biopsy procedures often yield insufficient tissue for molecular testing, and invasive surgical biopsies can be associated with significant cost as well as risk to the patient. Liquid biopsy offers an alternative and economical means for molecular characterization of tumors via a simple peripheral blood draw. This case report describes the ability of liquid biopsy to detect an ALK translocation where tissue analysis by fluorescence in situ hybridization was negative for the genetic alteration. Identification of an ALK rearrangement in circulating tumor cells from a blood specimen led to sequential targeted therapies that included crizotinib followed by alectinib. The patient demonstrated outstanding clinical response during treatment with each of the prescribed ALK inhibitors. This case demonstrates the clinical utility of Biocept’s liquid biopsy to detect actionable biomarkers by surveying the systemic landscape of a patient’s disease where identification of the same genetic drivers may be missed in analyses of heterogeneous tumor tissue.