Thrombocytopenia as a surrogate for cirrhosis and a marker for the identification of patients at high-risk for hepatocellular carcinoma

BACKGROUND. The objective of this study was to examine the usefulness of platelet counts in the diagnosis of cirrhosis and for identifying high-risk individuals in a community-based hepatocellular carcinoma (HCC) screening program. METHODS. Pilot Study 1 determined the correlation between platelet counts and pathologic hepatic fibrosis scores among individuals with chronic hepatitis B virus (HBV) infection (n = 122 patients) and hepatitis C virus (HCV) infection (n = 244 patients). Pilot Study 2 investigated proportions of individuals with thrombocytopenia (< 150 x 10(3)/mm(3)) among patients with HCC (n = 4042 patients). Pilot Study 3 demonstrated the correlation between platelet counts and ultrasonographic (US) parenchyma scores among anti-HCV-positive individuals (n = 75 patients). The core study was a 2-stage, community-based screening for HCC among residents age 40 years or older in townships with a high prevalence of anti-HCV (n = 4616 individuals) and in townships with a low prevalence of anti-HCV (n = 1694 individuals). Patients with thrombocytopenia were identified for US and alpha-fetoprotein screening. RESULTS. Among the individuals who were positive for anti-HCV, platelet counts decreased according to increased pathologic fibrosis scores or US scores for liver parenchyma disease: The best cutoff platelet count was 150 x 10(3)/mm(3) for a diagnosis of cirrhosis. The sensitivity and specificity were 68.2% and 76.4%, respectively, for pathologic cirrhosis and 76.2% and 87.8%, respectively, for US cirrhosis. Forty-eight percent of patients with HCC were thrombocytopenic. The proportion of thrombocytopenia was significantly greater in patients with HCV-related HCC (63%) than in patients with HBV-related HCC (42%). In the townships with high and low anti-HCV prevalence, the prevalence of thrombocytopenia was 17.9% and 6.1%, respectively, (P < .001), respectively. Twenty-five patients were diagnosed with HCC, and all of those patients resided in the high-prevalence township. CONCLUSIONS. Thrombocytopenia was a valid surrogate of cirrhosis and a valid marker for the identification of individuals at high-risk for HCC, especially in areas that had a high prevalence of HCV.