VARIABLES SERUM c-KIT p-value NEGATIVE POSITIVE Age <55 years 2 0 NS ≥55 years 0 25 Gender Male 2 14 NS Female 0 11 Location Stomach 2 16 NS Small intestine 0 8 Colon 0 1 Tumor size ≤2 cm 2 0 NS >2 cm 0 25 Histological type Spindle cells 1 18 NS Epithelioid cells 1 7 TNM stage I/II/III 2 21 NS IV 0 4

Table 3: Association between the preoperative levels of serum c-Kit and clinicopathological factors of the patients with GISTs Associations between the preoperative levels of serum c-Kit and clinicopathological factors of the patients with GISTs were examined with the t-test. Clinicopathological variables include age, gender, location, tumor size, histological type and TNM stage. NS, Not significant (p<0.05)