Evaluation of malignancy using Ki-67, p53, EGFR and COX-2 expressions in gastrointestinal stromal tumors

Table 1 Clinicopathological features of 96 patients with gastrointestinal stromal tumor

	n	% of 96 GISTs
Age (yr, median age = 55 yr)
< 40	12	12.5
40-60	52	54.2
> 60	32	33.3
Sex
Male	57	59.4
Female	39	40.6
Site
Esophagus	3	3.1
Gastric	45	46.9
Intestine	37	38.5
EGIST	11	11.5
Tumor size (cm, median size = 7.0)
≤ 2	7	7.3
> 2 to ≤ 5	29	30.2
> 5 to ≤ 10	34	35.4
> 10	26	27.1
Mitotic rate (per 50 HPFs)
≤ 5	54	56.3
6 to 10	28	29.2
> 10	14	14.6
Risk of malignancy
High risk	45	46.9
Intermediate risk	24	25.0
Low risk	24	25.0
Very low risk	3	3.1

GISTs: Gastrointestinal stromal tumors; EGIST: Extra GIST; HPFs: High-power fields.

Table 2 Ki-67, P53, epidermal growth factor receptor, cyclooxygenase-2 expression related to clinicopathological features

Variable	Ki-67				P53				EGFR				COX-2
	0+	1+	2+	P value	0+	1+	2+	P value	0+	1+	2+	P value	0+	1+	2+	P value
Tumor size (cm)
≤ 2	6	1	0	0.02	3	3	1	0.47	1	3	3	0.41	2	2	3	0.07
> 2 to ≤ 5	21	7	1		8	14	7		6	12	11		17	7	5
> 5 to ≤ 10	15	15	4		9	10	15		11	8	15		20	9	5
> 10	9	10	7		5	11	10		9	4	13		21	1	4
Total	51	33	12		25	38	33		27	27	42		60	19	17
Mitotic rate (per 50 HPFs)
≤ 5	39	12	3	< 0.001	17	20	17	0.04	16	16	22	0.77	38	8	8	0.41
> 5 to ≤ 10	10	14	4		8	13	7		7	6	15		14	8	6
> 10	2	7	5		0	5	9		4	5	5		8	3	3
Risk of malignancy
Very low + low risk	23	4	0	< 0.001	9	11	7	0.04	6	11	10	0.56	17	6	4	0.50
Intermediate risk	13	9	2		9	11	4		7	5	12		12	5	7
High risk	15	20	10		7	16	22		14	11	20		31	8	6

EGFR: Epidermal growth factor receptor; COX-2: Cyclooxygenase-2; HPFs: High-power fields.

Table 3 Multivariate analyses for disease-specific survival

Variable	RR (95% CI)	P value
Risk of malignancy
Very low/low risk	1.00 (reference)	< 0.001
Intermediate risk	1.32 (0.81-21.2)
High risk	12.23 (1.61-92.81)
Ki-67 expression
0+	1.00 (reference)	< 0.001
1+	3.75 (0.97-14.54)
2+	15.78 (4.25-59.37)
P53 expression
0+	1.00 (reference)	0.20
1+	2.11 (0.24-18.37)
2+	4.49 (0.54-37.11)
EGFR expression
0+	1.00 (reference)	0.50
1+	1.97 (0.60-6.50)
2+	1.17 (0.36-3.77)
COX-2 expression
0+	1.00 (reference)	0.19
1+	0.84 (0.42-4.36)
2+	1.99 (0.55-7.21)

EGFR: Epidermal growth factor receptor; COX-2: Cyclooxygenase-2; RR: Relative risk.