Performance of risk stratification systems for gastrointestinal stromal tumors: A multicenter study

Table 1 Demographic and clinicopathologic characteristics n (%)

	Overall (n = 1303)	Recurrence (107)	No recurrence (1196)	OR (95%CI)	P-value
Gender
Male	681 (52.3)	65 (60.7)	616 (51.5)
Female	622 (47.7)	42 (39.3)	580 (48.5)	0.686 (0.458, 1.028)	0.067
Age (yr)
Mean (SD)	55.77 (13.696)	55.76 (0.390)	55.83 (1.538)	1.000 (0.986, 1.015)	0.276
Tumor location
Gastric	873 (67.0)	38 (35.5)	835 (69.8)
Non-gastric	430 (33.0)	69 (64.5)	361 (30.2)	4.200 (2.774, 6.359)	< 0.05
Follow-up period (mo)
Mean (SD)	64.91 (35.793)	75.36 (4.608)	63.98 (0.995)	1.008 (1.003, 1.013)	< 0.05
Tumor size
Mean (SD)	5.14 (4.862)	9.01 (0.663)	4.80 (0.130)	1.128 (1.092, 1.165)	< 0.05
≤ 5 cm	775 (59.5)	28 (26.2)	747 (62.5)
> 5 cm	528 (40.5)	79 (73.8)	449 (37.5)	4.694 (3.003, 7.337)	< 0.05
Mitotic index
≤ 5/50 HPFs	877 (67.3)	44 (41.1)	833 (69.6)
> 5/50 HPFs	426 (32.7)	63 (58.9)	363 (30.4)	3.286 (2.193, 4.923)	< 0.05
Tumor rupture
Yes	34 (2.6)	27 (25.2)	7 (0.6)	57.327 (24.220, 135.685)
No	1269 (97.4)	80 (74.8)	1189 (99.4)		< 0.05
Modified NIH
Very low risk	347 (26.6)	14 (13.10)	333 (27.80)	0.182 (0.101, 0.329)	< 0.05
Low risk	394 (30.2)	10 (9.30)	384 (32.10)	0.113 (0.057, 0.222)	< 0.05
Intermediate risk	162 (12.4)	8 (7.50)	154 (12.90)	0.225 (0.106, 0.478)	< 0.05
High risk	400 (30.7)	75 (70.10)	325 (27.20)
AFIP criteria
Very low risk	619 (47.5)	15 (14.00)	604 (50.50)	0.081 (0.045, 0.146)	< 0.05
Low risk	250 (19.2)	16 (15.00)	234 (19.60)	0.224 (0.125, 0.401)	< 0.05
Intermediate risk	173 (13.3)	15 (14.00)	158 (13.20)	0.311 (0.170, 0.568)	< 0.05
High risk	261 (20.0)	61 (57.00)	200 (16.70)

OR: Odds ratio; CI: Confidence interval; SD: Standard deviation; HPF: High-power field; AFIP: Armed Forces Institute of Pathology; NIH: National Institutes of Health.

Table 2 Pairwise comparisons of receiver operating characteristic curves

	Difference (95%CI)	P-value
AFIP-MAP	0.3485	0.7275
AFIP-MSKCC_2 yr	-0.2933	0.7693
AFIP-MSKCC_5 yr	0.5597	0.5757
AFIP-Modified NIH	4.2594	< 0.05
MAP-MSKCC_2 yr	-0.4296	0.6675
MAP-MSKCC_5 yr	0.3559	0.7219
MAP-Modified NIH	1.7202	0.0854
MSKCC_2 yr-MSKCC_5 yr	0.7895	0.4298
MSKCC_2 yr-Modified NIH	1.2829	0.1995
MSKCC_5 yr-Modified NIH	0.5711	0.5679

MSKCC_2 yr: The 2-yr predicated probability of recurrence-free survival; MSKCC_5 yr: The 5-yr predicated probability of recurrence-free survival; MAP: Contour maps. AFIP: Armed Forces Institute of Pathology; MSKCC: Memorial Sloan Kettering Cancer Center; NIH: National Institutes of Health; CI: Confidence interval.