Liver transplantation for hepatocellular carcinoma: Is expansion of criteria justified?

Given the current information available, there is no compelling scientific data for expanding the accepted criteria for CLT in HCC. The proposals for expansion are based on explant examination, and up to now, no imaging techniques have been shown to have the same diagnostic accuracy as pathology. If the University from California-San Francisco and Pittsburgh definitions were to be applied to radiologic reports, then we would surely list patients with unidentified more advanced tumor stage in whom understaging would have an impact. These series lack of informative data on dropout rate and intention-to-treat survival and overall survival for the specific group of patients in which the expanded criteria is applied. Only one series of CLT from Mount Sinai reported specific outcomes for patients with expanded criteria (5-year survival: 44%, 5-year intention-to-treat survival: 25%). As we recently suggested, the proposed expanded tumor stage for LT should perhaps become the criteria for exclusion from the waiting list because of tumor progression. Consequently, making changes to a widely accepted and repeatedly proven criteria, which is the basis of the current organ allocation policy, based on the above data without prospective studies demonstrating good outcomes would be unwise. Results coming from LDLT should be considered aside, and are difficult to extrapolate toward policy decisions for cadaver transplants. A modest expansion of the criteria for LDLT in patients that otherwise will receive locoregional treatments might be considered in the setting of research studies, but not as a consolidated clinical practice. On the other hand, further refinement of the predictors of recurrence is needed. Vascular invasion, poor differentiation degree, tumor size, and in some studies, bilobar disease, are identified as the major predictors of recurrence. When restricting the selection criteria to patients with early HCC, however, only vascular invasion appears as a predictor of recurrence, if enough number of events in a given series allows this analysis. This marker is associated with some of the recurrences that have occurred in patients with tumors meeting the current Milan criteria (4-17% of the cases). Other factors, such as size or poor tumor differentiation, are indirect surrogates of this predictive marker. Even so, vascular invasion is an imperfect marker of the biologic aggressiveness of HCC. Conversely, some patients with tumors outside of the current limits might not recur, and it seems that there is no "cutoff" below which tumors will not recur, but that rather, there is a continuum along which an increase in the size and number of transplanted tumors will result in a linear increase in the likelihood of recurrence. Ongoing research in the genetic profiling of HCC may provide a more accurate method for stratifying HCC patients according to the risk of recurrent disease [55].