High platelet count as a poor prognostic factor for liver cancer patients without cirrhosis

A low platelet count, one of parameters of portal hypertension, is clinically a predictor of postoperative mortality, while platelets induce tumor development during growth factor secretion. In this study, we retrospectively investigated whether high platelet count negatively affects the survival of patients with hepatocellular carcinoma (HCC). Patients undergoing initial and curative resection for HCC were included. Surgical outcomes were compared between the high platelet (platelet count ≥ 20 × 10⁴/μL) and control (< 20 × 10⁴/μL) groups in patients without cirrhosis and between the low platelet (< 10 × 10⁴/μL) and control (≥ 10 × 10⁴/μL) groups in patients with cirrhosis. Among patients without cirrhosis, tumor was larger (P < 0.001) and tumor thrombus was more frequent (P < 0.001) in the high-platelet group than in the control group. After a median follow-up period of 3.1 years (range 0.2-16.2), median overall survival was 6.3 years (95% confidence interval [CI], 5.3-7.8) and 7.6 years (6.6-10.9) in the high-platelet (n = 273) and control (n = 562) groups, respectively (P = 0.027). Among patients with cirrhosis, liver function was worse (P < 0.001) and varices were more frequent (P < 0.001) in the low-platelet group. The median overall survival of patients in the low-platelet group (n = 172) was significantly shorter than that of patients in the control group (n = 275) (4.5 years [95% CI, 3.7-6.0] vs. 5.9 years [4.5-7.5], P = 0.038). Taken together, thrombocytopenia indicates poor prognosis in HCC patients with cirrhosis, while thrombocytosis is a poor prognostic predictor for those without cirrhosis.