The management of gastrointestinal stromal tumors: a model for targeted and multidisciplinary therapy of malignancy

Abstract

Gastrointestinal stromal tumor (GIST) has become a model for targeted therapy in cancer. The vast majority of GISTs contain an activating mutation in either the KIT or platelet-derived growth factor A (PDGFRA) gene. GIST is highly responsive to several selective tyrosine kinase inhibitors. In fact, this cancer has been converted to a chronic disease in some patients. Considerable progress has been made recently in our understanding of the natural history and molecular biology of GIST, risk stratification, and drug resistance. Despite the efficacy of targeted therapy, though, surgery remains the only curative primary treatment and cures >50% of GIST patients who present with localized disease. Adjuvant therapy with imatinib prolongs recurrence-free survival and may improve overall survival. Combined or sequential use of tyrosine kinase inhibitors with other agents following tumor molecular subtyping is an attractive next step in the management of GIST.

Figure 1

Schematic structures of KIT and platelet-derived growth factor receptor (PDGFR). The percentages indicate the frequency of mutations detected in each exon of the gene that encodes for the protein.

Figure 2

Recurrence-free survival in the American College of Surgeons Oncology Group (ACOSOG) trial Z9001. Produced with the permission of the publisher.