MKI67 and gastrointestinal stromal tumor: tumor size (P = 0.014, HR = 4.987, 95% CI: 1.383~17.989); Ki67 index (P<0.001, HR = 8.198, 95% CI: 2.680~25.007) was an independent risk factor for postoperative recurrence and metastasis in low-risk GIST patients (Table 2).