Selection tool alpha-fetoprotein for patients waiting for liver transplantation: How to easily manage a fractal algorithm

Alpha-fetoprotein (AFP) behavior in patients with hepatocellular carcinoma (HCC) waiting for liver transplant (LT) represents a perfect biological example of a fractal model in which its progressive modification and possible future prediction of its values are very hard to capture. As a consequence, AFP represents a useful but poorly manageable tool to increase the ability to better select HCC patients waiting for LT. Trying to find a "fil-rouge" in the recent literature, no definitive answers can be done to several open questions: (1) the best AFP value to adopt; (2) the best cut-off measurement; and (3) the best way to comfortably capture the effective, time-related, fluctuations of this biological marker. More, structured and prospective, studies using serial determination of AFP values within and without the context of locoregional therapies are needed in order to find the "ideal" (static and dynamic) cut-off values allowing to respond to all the still open questions in this field of transplant oncology.