National Experience on Down‐Staging of Hepatocellular Carcinoma Before Liver Transplant: Influence of Tumor Burden, Alpha‐Fetoprotein, and Wait Time

Identification of key factors associated with the risk of developing cardiovascular disease and quantification of this risk using multivariable prediction algorithms are among the major advances made in preventive cardiology and cardiovascular epidemiology in the 20th century. The ongoing discovery of new risk markers by scientists presents opportunities and challenges for statisticians and clinicians to evaluate these biomarkers and to develop new risk formulations that incorporate them. One of the key questions is how best to assess and quantify the improvement in risk prediction offered by these new models. Demonstration of a statistically significant association of a new biomarker with cardiovascular risk is not enough. Some researchers have advanced that the improvement in the area under the receiver-operating-characteristic curve (AUC) should be the main criterion, whereas others argue that better measures of performance of prediction models are needed. In this paper, we address this question by introducing two new measures, one based on integrated sensitivity and specificity and the other on reclassification tables. These new measures offer incremental information over the AUC. We discuss the properties of these new measures and contrast them with the AUC. We also develop simple asymptotic tests of significance. We illustrate the use of these measures with an example from the Framingham Heart Study. We propose that scientists consider these types of measures in addition to the AUC when assessing the performance of newer biomarkers.

The role of orthotopic liver transplantation in the treatment of patients with cirrhosis and hepatocellular carcinoma is controversial, and determining which patients are likely to have a good outcome after liver transplantation is difficult. We studied 48 patients with cirrhosis who had small, unresectable hepatocellular carcinomas and who underwent liver transplantation. In 94 percent of the patients, the cirrhosis was related to infection with hepatitis B virus, hepatitis C virus, or both. The presence of tumor was confirmed by biopsy or serum alpha-fetoprotein assay. The criteria for eligibility for transplantation were the presence of a tumor 5 cm or less in diameter in patients with single hepatocellular carcinomas and no more than three tumor nodules, each 3 cm or less in diameter, in patients with multiple tumors. Thirty-three patients with sufficient hepatic function underwent treatment for the tumor, mainly chemoembolization, before transplantation. After liver transplantation, the patients were followed prospectively for a median of 26 months (range, 9 to 54). No anticancer treatment was given after transplantation. The overall mortality rate was 17 percent. After four years, the actuarial survival rate was 75 percent and the rate of recurrence-free survival was 83 percent. Hepatocellular carcinoma recurred in four patients (8 percent). The overall and recurrence-free survival rates at four years among the 35 patients (73 percent of the total) who met the predetermined criteria for the selection of small hepatocellular carcinomas at pathological review of small hepatocellular carcinomas at pathological review of the explanted liver wer 85 percent and 92 percent, respectively, whereas the rates in the 13 patients (27 percent) whose tumors exceeded these limits were 50 percent and 59 percent, respectively (P=0.01 for overall survival; P=0.002 for recurrence-free survival). In this group of 48 patients with early-stage tumors, tumor-node-metastasis status, the number of tumors, the serum alphafetoprotein concentration, treatment received before transplantation, and 10 other variables were not significantly correlated with survival. Liver transplantation is an effective treatment for small, unresectable hepatocellular carcinomas in patients with cirrhosis.

The precise staging of hepatocellular carcinoma (HCC) based on the size and number of lesions that predict recurrence after orthotopic liver transplantation (OLT) has not been clearly established. We therefore analyzed the outcome of 70 consecutive patients with cirrhosis and HCC who underwent OLT over a 12-year period at our institution. Pathologic tumor staging of the explanted liver was based on the American Tumor Study Group modified Tumor-Node-Metastases (TNM) Staging Classification. Tumor recurrence occurred in 11.4% of patients after OLT. The Kaplan-Meier survival rates at 1 and 5 years were 91.3% and 72.4%, respectively, for patients with pT1 or pT2 HCC; and 82.4% and 74.1%, respectively, for pT3 tumors (P =.87). Patients with pT4 tumors, however, had a significantly worse 1-year survival of 33.3% (P =.0001). An alpha-fetoprotein (AFP) level > 1,000 ng/mL, total tumor diameter > 8 cm, age > or = 55 years and poorly differentiated histologic grade were also significant predictors for reduced survival in univariate analysis. Only pT4 stage and total tumor diameter remained statistically significant in multivariate analysis. Patients with HCC meeting the following criteria: solitary tumor < or = 6.5 cm, or < or = 3 nodules with the largest lesion < or = 4.5 cm and total tumor diameter < or = 8 cm, had survival rates of 90% and 75.2%, at 1 and 5 years, respectively, after OLT versus a 50% 1-year survival for patients with tumors exceeding these limits (P =.0005). We conclude that the current criteria for OLT based on tumor size may be modestly expanded while still preserving excellent survival after OLT.