Identification of liver transplant candidates with hepatocellular carcinoma and a very low dropout risk: implications for the current organ allocation policy.

It has been shown that patients with hepatocellular carcinoma (HCC) meeting the United Network for Organ Sharing T2 (Milan) criteria have an advantage in comparison with patients without HCC under the current organ allocation system for liver transplantation (LT). We hypothesized that within the T2 HCC group, there is a subgroup with a low risk of wait-list dropout that should not receive the same listing priority. This study evaluated 398 consecutive patients with T2 HCC listed for LT with a Model for End-Stage Liver Disease exception from March 2005 to January 2011 at our center. Competing risk (CR) regression was used to determine predictors of dropout. The probabilities of dropout due to tumor progression or death without LT according to the CR analysis were 9.4% at 6 months and 19.6% at 12 months. The median time from listing to LT was 8.8 months, and the median time from listing to dropout or death without LT was 7.2 months. Significant predictors of dropout or death without LT according to a multivariate CR regression included 1 tumor of 3.1 to 5 cm (versus 1 tumor of 3 cm or less), 2 or 3 tumors, a lack of a complete response to the first locoregional therapy (LRT), and a high alpha-fetoprotein (AFP) level after the first LRT. A subgroup (19.9%) that met certain criteria (1 tumor of 2 to 3 cm, a complete response after the first LRT, and an AFP level ≤ 20 ng/mL after the first LRT) had 1- and 2-year probabilities of dropout of 1.3% and 1.6%, respectively, whereas the probabilities were 21.6% and 26.5% for all other patients (P = 0.004). In conclusion, a combination of tumor characteristics and a complete response to the first LRT define a subgroup of patients with a very low risk of wait-list dropout who do not require the same listing priority. Our results may have important implications for the organ allocation policy for HCC.