Table 3.

Univariate and multivariate analyses of clinicopathological features and overall survival and time to recurrence in whole series (n = 187).

	Discovery cohort (n = 118)				Validation cohort (n = 69)
	OS		TTR		OS		TTR
Variable	HR (95%CI)	P	HR (95%CI)	P	HR (95%CI)	P	HR (95%CI)	P
Univariate analysis
Gender Male vs. Female
	0.754(0.322–1.761)	0.514	0.630(0.337–1.179)	0.148	0.617(0.224–1.700)	0.351	0.688(0.309–1.533)	0.361
Age (years) ≤60 vs. >60
	3.628(1.440–9.143)	0.006	1.743(0.973–3.122)	0.062	3.204(1.113–9.223)	0.031	2.176(0.973–4.863)	0.058
Site Gastric vs. Small intestine vs. Others
	2.045(1.165–3.588)	0.013	2.015(1.341–3.027)	0.001	1.785(0.899–3.546)	0.098	2.278(1.324–3.919)	0.003
Tumor size (cm) ≤5 vs. >5
	3.455(0.812–14.697)	0.093	2.908(1.149–7.355)	0.024	2.404(0.546–10.594)	0.246	4.261(1.004–18.088)	0.049
Nuclear abnormities Mild vs. Moderate or Distinct
	2.269(1.007–5.109)	0.048	1.630(0.919–2.892)	0.095	1.794(0.666–4.828)	0.247	2.061(0.932–4.561)	0.074
Mitotic index (/50HPF) ≤5 vs. >5
	4.619(1.377–15.495)	0.013	4.875(2.067–11.497)	<0.001	6.515(1.474–28.792)	0.013	7.315(2.181–24.528)	0.001
Morphology classification Low vs. Borderline vs. High
	2.319(1.235–4.354)	0.009	1.847(1.237–2.759)	0.003	1.916(0.791–4.642)	0.150	2.285(1.084–4.816)	0.030
Morphology Spindle vs. Epithelioid vs. Mixed
	1.212(0.743–1.979)	0.441	0.892(0.601–1.323)	0.570	1.046(0.569–1.923)	0.885	0.821(0.489–1.380)	0.458
NIH classification Low and Medium vs. High
	6.625(0.544–80.665)	0.138	3.988(1.328–11.978)	0.014	8.037(0.473–136.677)	0.149	8.280(0.896–76.498)	0.062
Postoperative imatinib treatment
Yes vs. No	1.802(0.747–4.348)	0.190	1.575(0.853–2.909)	0.147	3.220(0.914–11.342)	0.069	3.285(1.230–8.773)	0.018
Ki67 (%)# <5 vs. ≥5
	2.126(0.749–6.037)	0.157	2.640(1.269–5.493)	0.009	1.538(0.463–5.112)	0.482	1.938(0.735–5.108)	0.181
Mutation KIT vs. PDGFRA vs. WT KIT vs. Non-KIT PDGFRA vs. Non-PDGFRA
	0.849(0.329–2.189)	0.735	0.833(0.424–1.637)	0.596	1.097(0.354–3.394)	0.873	0.956(0.399–2.291)	0.920
	2.422(0.569–10.304)	0.231	2.386(0.856–6.651)	0.096	3.488(0.460–26.450)	0.227	6.265(0.845–46.444)	0.073
	0.039(0.000–5.835)	0.205	0.123(0.017–0.895)	0.038	0.039(0.000–15.470)	0.287	0.038(0.000–3.850)	0.165
Drug resistance
Yes vs. No	13.132(4.255–40.527)	<0.001	16.833(6.869–41.251)	<0.001	363.123(0.884–149227.953)	0.055	41.974(8.948–196.907)	<0.001
TLS Positive vs. Negative
	0.181(0.067–0.484)	0.001	0.397(0.220–0.719)	0.002	0.172(0.049–0.606)	0.006	0.278(0.116–0.668)	0.004
Multivariate analysis
Age (years) ≤60 vs. >60
	3.502(1.295–9.474)	0.014	NA	NA	3.167(1.088–9.223)	0.035	2.997(1.246–7.207)	0.014
Site Gastric vs. Small intestine vs. Others
	1.678(0.942–2.989)	0.079	1.796(1.055–3.057)	0.031	NA	NA	3.091(1.504–6.353)	0.002
Tumor size (cm) ≤5 vs. >5
	NA	NA	2.154(0.674–6.888)	0.196	NA	NA	0.757(0.146–3.910)	0.740
Nuclear abnormities Mild vs. Moderate or Distinct
	1.071(0.459–2.499)	0.875	NA	NA	NA	NA	NA	NA
Mitotic index (/50HPF) ≤5 vs. >5
	3.373(0.915–12.433)	0.068	7.872(1.517–40.854)	0.014	5.134(1.091–24.165)	0.038	9.684(2.326–40.315)	0.002
Morphology classification Low vs. Borderline vs. High
	0.879(0.414–1.867)	0.737	0.879(0.505–1.531)	0.649	NA	NA	0.533(0.240–1.184)	0.122
NIH classification Low vs. Medium vs. High
	NA	NA	1.156(0.332–4.025)	0.820	NA	NA	NA	NA
Postoperative imatinib treatment
Yes vs. No	0.676(0.249–1.839)	0.443	0.486(0.214–1.102)	0.084	0.958(0.233–3.936)	0.953	0.868(0.262–2.881)	0.817
Ki67 (%)# <5 vs. ≥5
	NA	NA	1.346(0.604–2.997)	0.467	NA	NA	NA	NA
TLS Positive vs. Negative
	0.180(0.061–0.534)	0.002	0.412(0.192–0.887)	0.023	0.219(0.056–0.862)	0.030	0.193(0.066–0.558)	0.002

Abbreviation: NIH, National Institutes of Health; PDGFRA, Platelet-derived growth factor receptor alpha; WT, Wide Type.

Cox regression analyzes were done for all the above data.

^# Available in 92 cases in discovery cohort and 52 cases in validation cohort.