Predictive value of multi-slice spiral computed tomography tumor diameter and necrotic ratio for very high-risk gastrointestinal stromal tumors

Table 1 Comparison of baseline data and clinical characteristics between the two groups

Characteristic	Very high-risk group (n = 35)	Non-very high-risk group (n = 123)	Statistic	P value
Age (year)	63 (55-70)	60 (52-67)	Z = -1.326	0.185
Sex (male)	21 (60.0)	66 (53.7)	χ2 = 0.556	0.456
BMI (kg/m2)	22.8 (20.5-24.9)	23.7 (21.5-26.0)	Z = -1.512	0.131
Abdominal pain/discomfort	22 (62.9)	63 (51.2)	χ2 = 1.665	0.197
Gastrointestinal bleeding	13 (37.1)	29 (23.6)	χ2 = 2.772	0.096
Palpable abdominal mass	9 (25.7)	9 (7.3)	χ2 = 9.812	0.002
Asymptomatic (incidentally detected)	5 (14.3)	40 (32.5)	χ2 = 4.714	0.030
Hemoglobin (g/L)	112 (98-126)	128 (115-140)	Z = -3.845	< 0.001
Platelet count (× 109/L)	240 (195-298)	208 (175-255)	Z = -2.501	0.012
Neutrophil count (× 109/L)	5.8 (4.6-7.1)	4.4 (3.7-5.3)	Z = -4.116	< 0.001
Lymphocyte count (× 109/L)	1.7 (1.3-2.0)	2.1 (1.7-2.5)	Z = -3.782	< 0.001
NLR	3.1 (2.3-4.5)	2.1 (1.6-2.8)	Z = -4.892	< 0.001
Albumin (g/L)	38.0 (35.1-40.5)	40.8 (38.0-43.5)	Z = -3.124	0.002
Tumor location			χ2 = 23.453	< 0.001
Stomach	12 (34.3)	90 (73.2)
Small intestine	18 (51.4)	30 (24.4)
Colorectum and others	5 (14.3)	3 (2.4)
Tumor rupture	7 (20.0)	0 (0.0)	Fisher’s exact test	< 0.001
Mitotic count (> 5/50 HPF)	31 (88.6)	10 (8.1)	χ2 = 95.321	< 0.001
Ki-67 index (%)	15 (10-25)	3 (2-5)	Z = -9.123	< 0.001

Continuous variables are presented as mean ± SD or median and interquartile range. Categorical variables are reported as n (%). BMI: Body mass index; NLR: Neutrophil-to-lymphocyte ratio; HPF: High-power field.

Table 2 Comparison of multi-slice spiral computed tomography features between the two groups

MSCT feature	Very high-risk group (n = 35)	Non-very high-risk group (n = 123)	Statistic	P value
Growth pattern			χ2 = 15.237	< 0.001
Intraluminal/extraluminal	15 (42.9)	95 (77.2)
Mixed intra- and extraluminal	20 (57.1)	28 (22.8)
Irregular or lobulated morphology	28 (80.0)	39 (31.7)	χ2 = 26.811	< 0.001
Ill-defined margin	25 (71.4)	34 (27.6)	χ2 = 23.456	< 0.001
Heterogeneous enhancement	32 (91.4)	59 (48.0)	χ2 = 21.543	< 0.001
Marked enhancement	25 (71.4)	60 (48.8)	χ2 = 5.832	0.016
Signs of adjacent organ invasion	16 (45.7)	9 (7.3)	χ2 = 32.115	< 0.001
Distant metastasis	10 (28.6)	1 (0.8)	Fisher’s exact test	< 0.001
Maximum tumor diameter (cm)	12.1 (9.5-15.8)	4.5 (2.8-7.1)	Z = -8.245	< 0.001
NAR (%)	28.5 (18.4-42.1)	5.2 (1.5-12.8)	Z = -9.012	< 0.001

Continuous variables are presented as median and interquartile range. Categorical variables are reported as n (%). MSCT: Multi-slice spiral computed tomography; NAR: Necrotic area ratio.

Table 3 Variable assignment table for multivariate logistic regression analysis

Variable type	Variable name	Coding/definition
Dependent variable	GIST risk classification	0 = non-very high-risk group; 1 = very high-risk group
Independent variables	Palpable abdominal mass	0 = no; 1 = yes
	Asymptomatic	0 = no; 1 = yes
	Hemoglobin	Continuous variable (g/L)
	Platelet count	Continuous variable (× 109 /L)
	NLR	Continuous variable
	Albumin	Continuous variable (g/L)
	Tumor location	0 = stomach; 1 = non-gastric
	Maximum tumor diameter	Continuous variable (cm)
	NAR	Continuous variable (%)
	Growth pattern (mixed intra- and extraluminal)	0 = no (intraluminal or extraluminal); 1 = yes
	Irregular morphology	0 = no; 1 = yes
	Ill-defined margin	0 = no; 1 = yes
	Heterogeneous enhancement	0 = no; 1 = yes
	Marked enhancement	0 = no (mild/moderate); 1 = yes
	Signs of adjacent organ invasion	0 = no; 1 = yes

GIST: Gastrointestinal stromal tumor; NLR: Neutrophil-to-lymphocyte ratio; NAR: Necrotic area ratio.

Table 4 Multivariate logistic regression analysis of predictive factors for the very high-risk group of gastrointestinal stromal tumor

Variable	β	Standard error	Wald χ2	OR	95%CI for OR	P value
Palpable abdominal mass (yes vs no)	0.701	0.605	1.343	2.02	0.62-6.61	0.246
Asymptomatic (yes vs no)	-0.285	0.621	0.211	0.75	0.22-2.54	0.646
Hemoglobin (g/L)	-0.012	0.018	0.444	0.99	0.95-1.03	0.505
Platelet count (× 109/L)	0.005	0.003	1.852	1.01	1.00-1.01	0.173
NLR	0.298	0.180	2.741	1.35	0.95-1.92	0.098
Albumin (g/L)	-0.081	0.067	1.463	0.92	0.81-1.05	0.226
Tumor location (non-gastric vs gastric)	0.522	0.511	1.044	1.69	0.62-4.59	0.307
Maximum tumor diameter (cm)	0.265	0.080	10.984	1.30	1.11-1.52	0.001
NAR (%)	0.116	0.029	16.024	1.12	1.06-1.19	< 0.001
Growth pattern (mixed intra- and extraluminal vs no)	0.450	0.542	0.689	1.57	0.54-4.54	0.407
Irregular morphology (yes vs no)	0.655	0.591	1.229	1.93	0.61-6.13	0.268
Ill-defined margin (yes vs no)	0.612	0.545	1.262	1.84	0.63-5.36	0.261
Heterogeneous enhancement (yes vs no)	0.884	0.725	1.487	2.42	0.58-10.05	0.223
Marked enhancement (yes vs no)	0.331	0.481	0.474	1.39	0.54-3.57	0.491
Signs of adjacent organ invasion (yes vs no)	0.981	0.632	2.410	2.67	0.77-9.21	0.121
Constant	-9.856	2.345	17.656	-	-	< 0.001

NLR: Neutrophil-to-lymphocyte ratio; NAR: Necrotic area ratio; OR: Odds ratio; 95%CI: 95% confidence interval.