SURVIVAL SIMULATION OF HEPATOCELLULAR-CARCINOMA DERIVED FROM FOLLOW-UP-STUDIES OF 450 PATIENTS

A simulation model to predict the survival probability of individual p atients with hepatocellular carcinoma (HCC) after therapy was derived from the results of various therapies and follow-up studies of 450 HCC patients. Twenty-two prognostically important variables were analyzed by Cox's proportinal hazards model. The 9 significant variables that were extracted were used to build the simulation. In this model, S(t), the expected estimated survival rate for individual patient at time t (month), is calculated by the following equation: S(t) = {exp(-0.0365 5t)}^{exp(0.9479([portal vein invasion]-0.222)+0.3846 ([tumor number]- 2.00)+0.2578 ([tumor size]-3.231)+0.0742([log(e) -5.647)+0.8184([metas tasis]-0.036)+0.2810([Child's class]-1.689)-0.7088([transcatheter arte rial embolization]-0.578)-0.9746([percutaneous ethanol injection]-0.15 3)-0.5377([hepatectomy]-0.109))} The validity of the model was assesse d using a split-sample technique. This paper does not discuss the supe riority or inferiority of the therapies, because some selection bias f or prognostic factors among the therapies can not be completely exclud ed. But this model is proposed as a practical model to predict the sur vival. of patients with HCC.