A Pilot Prospective Study of Refractory Solid Tumor Patients for NGS-Based Targeted Anticancer Therapy12

With the advent of next-generation sequencing (NGS), targeted sequencing is now contributing to decision making for which chemotherapeutics to administer to cancer patients, especially in refractory and metastatic cancer. Given that most patients with refractory cancer develop resistance to chemotherapy and have few treatment options, we performed NGS test to evaluate the efficacy and clinical feasibility of NGS-based targeted anticancer therapy. We used a gene panel for capturing target regions covering 83 cancer-related genes. A total of 25 refractory metastatic solid tumor patients were enrolled in this study. Among the 25 patients, 7 had FDA-approved drug-responsive or -resistant alterations. However, the effectiveness of targeted therapy was assessed by follow-up in three patients (12%). These included crizotinib for ALK-EML4 fusion in a malignancy of undefined origin patient and everolimus for AKT3 amplification in a uterine sarcoma patient. In addition, we identified a KRAS codon 146 mutation (A146V), which is associated with resistance to anti-EGFR, in a cetuximab-resistant colon cancer patient with wild-type KRAS exons 2 and 12, and EGFR amplification. He received bevacizumab therapy. All three patients showed partial response after targeted therapy. Furthermore, we characterized KRAS A146V biologically using colon cancer cells. In conclusion, this study suggests that targeted therapy based on NGS test may be a good choice for improving the care of patients with refractory solid tumors.