Current treatment strategies and future perspectives for gastrointestinal stromal tumors

Table 4 Clinical features of various molecular subtypes of gastrointestinal stromal tumors

Gene mutation	Exon	Proportion	Common mutation	Treatment	Characteristics
KIT	11	70%	Del-inc557/558	Sensitive to imatinib, secondary mutation resistant to sunitinib, some effect for regorafenib	High risk of recurrence
			p.W557_K558 del		Adverse prognosis effect in stomach
			SNSs and Dup		Relatively good prognosis
	9	10%	A502-'503 Dup	Need high dose of imatinib, effective for sunitinib	Mainly in small intestinal, worse prognosis
	13	1%	Lys642Glu	Secondary mutation resistant to imatinib	Mainly in small intestinal
	17	1%	Asn822Lys	Secondary mutation resistant to imatinib and sunitinib, but responding to regorafenib	Mainly in small intestinal
	8	0.30%	Del-Asp419	Sensitive to imatinib	Extragastric, metastatic prone nature
PDGFRA	18	5%	Asp842Val (D842V)	Responds to avapritinib, resistance to imatinib	Mainly in gastric and favorable prognosis
	14	1%	Apn659Lys	Sensitive to imatinib	Relatively good prognosis
	12		V561D	Sensitive to imatinib	Relatively good prognosis
Wild-type GIST		10%-15%	SDH-deficient	Not sensitive to imatinib, response to sunitinib, regorafenib	Overall indolent disease
			NF1	Not sensitive to imatinib, response to sunitinib	Mainly in the small intestine and good prognosis
	15	1%	BRAF	Not sensitive to imatinib, response to dabrafenib	Relatively good prognosis
			K-RAS	Not sensitive to imatinib

PDGFRA: Platelet derived growth factor receptor; SNSs: Single-nucleotide substitutions; Dup: Duplication; SDH: Succinate dehydrogenase; NF1: Neurofibromatosis type 1.