Serial Analysis of Circulating Tumor Cells (CTCs) May Provide Biomarker Predictive of NSCLC Response to Crizotinib

Among patients with non-small cell lung cancer (NSCLC) fueled by ALK (anaplastic lymphoma kinase) gene alterations who were being treated with crizotinib (Xalkori), a decrease in the number of circulating tumor cells (CTCs) harboring increased numbers of copies of the ALK gene over the first two months of treatment was associated with increased progression-free survival. These results were published in the May 2017 issue of Cancer Research. The open-access article is titled “Circulating Tumor Cells with Aberrant ALK Copy Number Predict Progression-Free Survival During Crizotinib Treatment in ALK-Rearranged Non–Small Cell Lung Cancer Patients.” The research group was led by Françoise Farace, PhD, leader of the circulating cells team at Gustave Roussy, INSERM, Université Paris-Saclay, Villejuif, France. Approximately 4 percent of NSCLCs are driven by genetic aberrations called ALK gene rearrangements, according to Dr. Farace. "The approval of the ALK-targeted therapeutic crizotinib has improved outcomes for patients with ALK-rearranged NSCLC, but the duration of responses varies widely, from a few months to several years," she said. Dr. Farace and colleagues prospectively recruited 39 patients with ALK-rearranged NSCLC to the study. All patients had a blood sample taken before starting crizotinib treatment. Blood samples were taken about two months later for 29 of these patients; 10 patients received follow-up care at a different center and no serial blood samples were available for analysis. After enriching for CTCs, the researchers analyzed the samples for ALK rearrangements and for an increase in the number of copies of the ALK gene. All patients had both CTCs with ALK rearrangements and CTCs with ALK copy number gain before treatment and at two months.
Login Or Register To Read Full Story