ABSTRACT
Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumors in the gastrointestinal tract. Though surgical resection is the only radical treatment, postoperative recurrence and metastasis often occur. The first-line therapy for the treatment of recurrent, metastatic and unresectable GIST is imatinib. More than 80% of patients can benefit from imatinib treatment, but half of patients will still have recurrence or metastasis within 2 years after treatment initiation, and secondary drug resistance is a major cause of disease progression. Therefore, adeep understanding of the mechanisms of secondary drug resistance will guide us to develop personalized therapeutic schedule in the future. This article describes the mechanism of IM secondary resistance from the aspects of gene alteration, abnormal activation of signal transduction pathway, autophagy, apoptosis and drug concentration. It is found that single drug therapy has certain limitations in patients with secondary resistance to IM. Using IM combined with downstream signaling molecule inhibitors, autophagy inhibitors, insulin-like growth factor 1 receptor (IGF-1R) inhibitors, heat shock protein 90 (HSP90) inhibitors, cytotoxic T lymphocyte - associated antigen - 4 (CTLA - 4) antibodies and mitochondrial inhibitors provide us new therapeutic ideas. However, these combination treatments are still in the research phase, and further trials are needed to confirm the safety and efficacy. With the gradual deepening of research on drug resistance mechanisms, it will provide more solutions to the current serious drug resistance problem.