Perbedaan ekspresi Beta-catenin pada faktor Prognosis Karsinoma Sel Hati: Studi pada Alfa-Fetoprotein, Derajat Diferensiasi dan Invasi Mikrovaskular = Beta-catenin expression and its association with prognostic factors in hepatocellular carcinoma: A study on alpha-fetoprotein, tumor grade and microvascular invasion