Targeted therapy of gastrointestinal stromal tumours

Abstract

Gastrointestinal stromal tumours (GISTs) are mesen­ chymal neoplasms originating in the gastrointestinal tract, usually in the stomach or the small intestine, and rarely elsewhere in the abdomen. The malignant potential of GISTs is variable ranging from small lesions with a benign behaviour to fatal sarcomas. The majo­ rity of the tumours stain positively for the CD­117 (KIT) and discovered on GIST­1 (DOG­1 or anoctamin 1) expression, and they are characterized by the presence of a driver kinase­activating mutation in either KIT or platelet­derived growth factor receptor α. Although surgery is the primary modality of treatment, almost half of the patients have disease recurrence following surgery, which highlights the need for an effective adjuvant therapy. Traditionally, GISTs are considered chemotherapy and radiotherapy resistant. With the advent of targeted therapy (tyrosine kinase inhibitors), there has been a paradigm shift in the management of GISTs in the last decade. We present a comprehensive review of targeted therapy in the management of GISTs. Core tip: Gastrointestinal stromal tumors (GISTs) are common mesenchymal tumours of the gastrointestinal tract. They are characterized by the presence of a driver kinase­activating mutation in either CD­117 or platelet­derived growth factor receptor α. Development of tyrosine kinase inhibitors has led to a paradigm shift in the management of GISTs. Surgery is the primary modality of treatment in localized non­metastatic GISTs. Adjuvant Imatinib for three years is a preferred option for high­risk patients to lessen disease recurrence. The role of neoadjuvant Imatinib is evolving. Imatinib, Sunitinib, and Regorafinib are recommended as first, second and third­line targeted therapies, respectively, for the management of metastatic GISTs.