Targeted therapy: twenty years of success and failures

During the last twenty years the identification of oncogenic driver mutations has enabled the development of targeted therapies that specifically inhibit mutationinduced pathways and showed unprecedented clinical response compared with conventional chemotherapy. Patients with disseminated non-small cell lung cancer, melanoma, GIST and etc. harboring the genetic alterations are demonstrated a dramatic tumor response and longer overall survival. Tumor genetic testing or liquid biopsy has become a routine procedure in the clinic. Several factors are limited the efficacy of targeted therapy, including the small proportion of patients with
actionable alterations, the complex heterogeneity and rapid evolution of tumors, which call for multitargeted therapeutic
approaches that are likely to be highly toxic, and finally limited availability of such targeted agents. Both success and failures
of the targeted therapy is a beginning of the long road to precision oncology. Here we review current implementations of
targeted therapy in clinical practice and highlight the achievements and limitation of biomarker-driven approach.