Treatment of patients with advanced gastrointestinal stromal tumor of small bowel: Implications of imatinib mesylate

Table 1 Demographic data of 55 advanced and metastatic small bowel GIST patients treated with or without imatinib meslyate

	Non-Glivec (%)	Imatinib meslyate (%)	P
	(n = 33)	(n = 22)
Age (yr)	56.5 ± 11.1	55.7 ± 15.4	0.803
Gender (M : F)	17 : 16	13 : 09	0.58
Location
Duodenum	4 (12.1)	5 (22.7)
Jejunum	22 (66.7)	8 (36.4)
Ileum	7 (21.2)	6 (27.3)
Multiple	0 (0)	3 (13.6)	0.05
Tumor size
Mean/Median (cm)	10.3 ± 4.9/9.0	11.7 ± 5.1/10.5	0.315
Range (cm)	3.5-25	4-24
Recurrence			0.022
Liver	28 (84.8)	11 (50)
Peritoneum	10 (30.3)	10 (45.5)
Retroperitoneum	4 (12.1)	5 (22.7)
Local	4 (12.1)	10 (45.5)
Others	1 (0.3)	4 (18.2)

M: Male; F: Female.

Table 2 Prognosis of 55 advanced and metastatic small bowel GIST patients treated with or without imatinib meslyate

	Non-Glivec (%)(n = 33)			Imatinib meslyate (%)(n = 22)				P
	Re-resection (n = 6)	C/T (n = 5)	Conservative Treatment (n = 22)	CR (n = 0)	PR (n = 15)	SD (n = 4)	PD (n = 3)
PRS (m) (median/mean)	6.7/14.7			-/72.6				0.00001
Mean	36.2	4.8	9.6	75.6		31.6
Median	15.7	3.7	5.9	-		24.7
95% CI of mean	7.5-65.0	2.3-7.3	6.1-13.0	67.5-87.0		22.0-41.2
Log-rank (p)	0.048			0.462
OS (m) (median/mean)	33.6/49.2			137.7/128.9				0.00001
Mean	73.1	28.5	48.2	140.1		53.2
Median	47.5	23.5	33.2	137.7		50.9
95% CI of mean	27.0-119.3	18.7-38.4	30.3-66.1	136.7-143.3		50.0-56.4
Log-rank	0.189			0.083

Table 3 Antitumor response and mutation status of 22 advanced and metastatic small bowel GIST patients treated with imatinib meslyate

	CR	PR	SD	PD	P
Exon 9 (n = 3)	0	2	0	1	0.486
Exon 11(n = 13)	0	9	2	2
No mutation (n = 3)	0	3	0	0
Insufficient specimen (n = 3)	0	1	2	0
	Exon 9 (n = 3)		Exon 11 (n = 13)		1.0
PR, n (%)	2 (66.7)		9 (69.2)
SD + PD, n (%)	1 (33.3)		4 (30.8)

PR: Partial response; SD: Stationary disease; PD: Progression of disease.

Table 4 Mutation patterns of 22 advanced and metastatic small bowel GIST patients treated with imatinib meslyate

Case (n)	Mutation pattern
2	Deletion mutation at codon 551-556 in exon 11
4	Deletion mutation at codon 557-561 in exon 11
8	Deletion mutation at codon 550-5 in exon 11
12	Deletion mutation at codon 563-576 in exon 11
13	Deletion mutation at codon 575-576 in exon 11
19	Deletion mutation at codon 569-575 in the exon 11
24	Deletion mutation at of codon 555-572 in exon 11
1	Deletion and insertion mutations at codons 563-572 in exon 11
15	Deletion and insertion mutations at codons 557-8 in the exon 11
22	Deletion and insertion mutations at codon 563-574 in exon 11
3	Missense mutation at codon 556 in exon 11
18	Missense mutation at codon 576 in the exon 11
21	Missense mutation at codon 557 in exon 11
7	Insertion mutation at codon 502-3 AY(alanine and tyrosin) in exon 9
9	Insertion mutation at codon 502-3 AY(alanine and tyrosin) in exon 9
17	Insertion mutation at codon 502-3 AY(alanine and tyrosin) in exon 9
10	No mutation
14	No mutation
20	No mutation