Table 1. Clinicopathological features of 25 patients with KIT/PDGRFA/BRAF wild-type GIST.

										SDH IHC expression
Case	Gender	Age (years)	Primary site	Tumor largest size (cm)	Histologic cell subtype	Mitosis/50 HPF	NIH risk classificationa	NCCN risk classificationb	Molecular alterationsSDHB, SDHC, SDHD	SDHA	SDHB	Curative surgery -R classification	Follow-up (months/status)
1	M	26	Stomach	6	Spindle	16/50	High	High	Pos (germline)c c.T282A, p.Ile44Asn	High	Negative	R0	104/ANED
2	M	30	Stomach	10	Epithelioid	8/50	High	High	Pos (germline)d SDHB c.1-10413_73-3866del	High	Negative	R0	156/DUC
3	M	42	Stomach	3	Spindle	12/50	High	Moderate	Pos (germline)e SDHB c.1-10413_73-3866del	High	Negative	R0	94/ANED
4	M	49	Stomach	6.5	Epithelioid	7/50	High	High	Negf	Negative	Negative	R0	271/ANED
5	F	58	Stomach	3.5	Epithelioid	1/50	Low	Very low	Negf	Negative	Negative	R1	198/ANED
6	M	75	Duodenum	>3	Spindle	1/50	NA	NA	Pos (somatic) SDHB c.1-10413_73-3866del	Moderate	Moderate	NR	9/DOD
7	F	77	Small intestine	6	Spindle	1/50	Intermediate	Moderate	Neg	High	High	R0	132/DUC
8	M	74	Stomach	3	Mixed	5/50	Low	Very low	Neg	High	High	R0	120/DUC
9	F	72	Stomach	8	Spindle	4/50	Intermediate	Low	Neg	High	High	R1	35/ANED
10	F	53	Small intestine	3.5	Spindle	4/50	Low	Low	Neg	High	Moderate	R0	124/ANED
11	M	62	Stomach	6.5	Spindle	5/50	Intermediate	Low	Neg	High	Low	R0	111/ANED
12	M	73	Small intestine	6	Spindle	3/50	Intermediate	Moderate	Neg	High	High	R0	106/ANED
13	F	66	Stomach	14	Spindle	5/50	High	Moderate	Neg	Moderate	Low	R0	129/ANED
14	F	63	Small intestine	6.5	Mixed	2/50	Intermediate	Moderate	Neg	High	Moderate	R0	270/ANED
15	M	52	Small intestine	9.5	Spindle	4/50	Intermediate	Moderate	Neg	High	Moderate	R0	213/ANED
16	M	55	Small intestine	4	Spindle	1/50	Low	Low	Neg	High	Moderate	R0	66/DUC
17	F	50	Stomach	5.6	Spindle	6/50	High	High	Neg	High	Moderate	R1	198/ANED
18	F	82	Stomach	7	Epithelioid	5/50	Intermediate	Low	Neg	Low	Low	R0	80/DUC
19	M	81	Stomach	3.3	Spindle	1/50	Low	Very low	Neg	Moderate	Moderate	R0	75/DUC
20	M	81	Colon	12.5	Epithelioid	12/50	High	High	Neg	High	Moderate	R2	0/DOD
21	M	60	ND	13	Mixed	4/50	High	High	Neg	High	Low	NR	48/DOD
22	M	69	Stomach	19	Spindle	8/50	High	High	Neg	High	Moderate	R2	4/DOD
23	M	76	Stomach	6	Spindle	2/50	Intermediate	Low	Neg	Moderate	Low	R0	105/ANED
24	F	41	Stomach	4,5	Spindle	2/50	Low	Very low	Neg	High	Moderate	R0	94/ANED
25	M	57	Stomach	17	Spindle	2/50	High	Moderate	Neg	Moderate	Moderate	R0	107/ANED

Abbreviations: ANED, alive, no evidence of disease; DUC, dead of unrelated causes; DOD, dead of disease; F, female; GIST, gastrointestinal stromal tumor; HPF, high-power field; IHC, immunohistochemistry; M, male; NA, not applicable; NCCN, National Comprehensive Cancer Network; ND, not determined; Neg, negative; NIH, National Institutes of Health; NR, no resection; Pos, positive; R0, no macroscopic residual tumor (potentially curative surgery); R1, microscopic residual tumor; R2, macroscopic residual tumor (non-curative surgery); SDH, succinate dehydrogenase.

^aNIH risk classification¹ for primary GIST.

^bNCCN risk classification³⁴ for primary GIST.

^cLoss of heterozygosity (LOH) of the SDHB normal allele in the tumor.

^dTumor with complete loss of SDHB promoter and exon 1 (MLPA analysis).

^eTumor with complete loss of SDHB promoter and loss heterozygosity (LOH) exon 1 (MLPA analysis).

^fScreening of mutations in SDHA exons performed in germline DNA of the patient peripheral blood lymphocytes.