Objective: To investigate the association between the Ki-67 expression and the prognosis of patients with primary liver cancer receiving prophylactic transarterial chemoembolization (TACE) after radical resection.  
Methods: Using a retrospective cohort method, a total of 150 patients with primary liver cancer udergoing prophylactic TACE within 2 months after radical resection in Mengchao Hepatobiliary Hospital of Fujian Medical University from December 2014 to January 2016 were enrolled. According to postoperative pathological score of Ki-67 in the tumor tissue, the patients were divided into low Ki-67 expression group (Ki-67 score ≤20%, 44 cases) and high Ki-67 expression group (Ki-67 score >20%, 106 cases). The relations of Ki-67 expression level with the clinicopathologic factors as well as recurrence and survival of the patients were analyzed.
Results: The proportions of patients with multiple lesions, incomplete capsule and concomitant microvascular tumor thrombus were significantly higher in high Ki-67 expression group than those in low Ki-67 expression group (all P<0.05). High Ki-67 expression along with multiple lesions and large tumor size were independent risk factors for disease-free survival of the patients (all P<0.05); high Ki-67 expression together with multiple lesions, large tumor size, incomplete tumor capsule and presence of microvascular tumor thrombus were independent risk factors for overall survival of the patients (all P<0.05). The recurrence rate was significantly higher (57.9% vs. 37.7%, χ2=6.777, P<0.05) and the overall survival rate was significantly lower (45.6% vs. 75.9%, χ2=8.447, P<0.05) in patients in high Ki-67 expression group than those in patients in low Ki-67 expression group.
Conclusion: The Ki-67 expression level exerts significant impact on the prognosis of patients with primary liver cancer undergoing prophylactic TACE after radical resection. Those with high Ki-67 expression may have an unfavorable prognosis.