Table 4. Univariate analysis of factors influencing RFS.

Factor		5-year RFS rate (%)	P value
Gender	Male: female	55.7∶80.6	0.024
Age	<60: ≥60	71.6∶61.0	NS (0.669)
Gastrointestinal bleeding	Yes: no	50.7∶75.7	0.029
Primary tumor site	Gastric: non-gastric	80.5∶39.7	<0.001
Primary tumor size	≤5 cm: 5.1–10 cm: >10 cm	89.7∶67.5∶36.7	<0.001
Mitotic index (per 50 HPFs)	≤5∶6–10: >10	80.4∶35.0∶18.2	<0.001
Surrounding tissues invasion	Yes: no	40.0∶73.1	0.002
Tumor necrosis	Yes: no	55.0∶82.4	0.003
Predominant cell type	Spindle: epithelioid/mixed	68.8∶57.7	0.03
Cellularity	High: moderate/paucicellular	64.2∶68.7	NS (0.551)
Postoperative IM treatment	Yes: no	79.2∶66.6	NS (0.434)
AFIP-Miettinen criteria	Very low: low: moderate: high	100∶91.7∶66.7∶30.2	<0.001
Ki67	<5%: ≥5%	79.4∶27.4	<0.001
p16	≤20%: >20%	76.4∶54.8	0.021
p27 (index*)	<100∶100–200:>200	65.7∶64.6∶68.6	NS (0.846)
p53 (index*)	<10: ≥10	76.3∶54.9	0.012
SKP2	≤10%: >10%	74.6∶40.0	<0.001
CD133	(−): (+): (++): (+++)	52.6∶68.0∶57.5∶80.4	NS (0.183)
actin	(−): (+, ++, +++)	66.5∶66.3	NS (0.915)
Mutation status	KIT exon 11 deletion:	48.3∶74.3∶72.0	0.022
	KIT exon 11 others: others

^*Scoring index: staining intensity × percentage of positively stained cells; NS, not significant.