title: Predicting the probability of progression-free survival in patients with small hepatocellular carcinoma.
abstract: Allocation of cadaveric livers to patients based on such objective medical urgency data as the Model for End-Stage Liver Disease (MELD) score may not benefit patients with small hepatocellular carcinomas (HCCs). To ensure that these patients have a fair opportunity of receiving a cadaveric organ, the risk for death caused by HCC and tumor progression beyond 5 cm should be considered. Using a Markov model, two hypothetical cohorts of patients with small hepatomas were assumed to have either (1) Gompertzian tumor growth, in which initial exponential growth decreases as tumor size increases; or (2) rapid exponential growth. The model tracked the number of patients who either died or had tumor progression beyond 5 cm. These results were used to back-calculate an equivalent MELD score for patients with small HCCs. All probabilities in the model were varied simultaneously using a Monte Carlo simulation. The Gompertzian growth model predicted that patients with a 1- and 4-cm tumor have 1-year progression-free survival rates of 70% (HCC-specific MELD score 6) and 66% (HCC-specific MELD score 8), respectively. When assuming rapid exponential growth, patients with a 1- and 4-cm tumor have progression-free survival rates of 69% (HCC-specific MELD score 6) and 12% (HCC-specific MELD score 24), respectively. Our model predicted that the risk for death caused by HCC or tumor progression beyond 5 cm should increase with larger initial tumor size in patients with small hepatomas. To ensure that these patients have a fair opportunity to receive a cadaveric organ, HCC-specific scores predicted by our model could be added to MELD scores of patients with HCC.
authors.affiliation: Department of Medicine, Division of Clinical Decision Making, New England Medical Center, Tufts University School of Medicine, Boston, MA 02111, USA.
authors.forename: Steve J
authors.initials: SJ
authors.lastname: Cheng
authors.forename: Richard B
authors.initials: RB
authors.lastname: Freeman
authors.forename: John B
authors.initials: JB
authors.lastname: Wong
mesh_terms: D002102:Cadaver; D006528:Carcinoma, Hepatocellular / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D018572:Disease-Free Survival; D006801:Humans; D008113:Liver Neoplasms / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D016031:Liver Transplantation / Q000401:mortality / Q000502:physiology*; D008875:Middle Aged; D008954:Models, Biological; D009010:Monte Carlo Method; D011379:Prognosis; D015996:Survival Rate; D013997:Time Factors; D014019:Tissue Donors