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

Abstract

It has been shown that patients with hepatocellular carcinoma (HCC) meeting UNOS T2 (Milan) criteria are advantaged compared to patients without HCC under the current organ allocation system for liver transplant (LT). We hypothesize that within T2 HCC, there is a subgroup with a low risk of waitlist dropout, and should not receive the same listing priority. This study evaluated 398 consecutive patients with T2 HCC listed for LT with MELD exception from 2005 to 2010 at our center. Competing risk (CR) regression was used to determine predictors of dropout. Probabilities of dropout due to tumor progression or death without LT by 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 from listing to dropout or death without LT was 7.2 months. Significant predictors of dropout or death without LT by multivariate CR regression included 1 tumor 3–5 cm (vs. ≤3 cm), 2 or 3 tumors, lack of a complete response to first loco-regional therapy (LRT), and high alpha-fetoprotein (AFP) after the first LRT. A subgroup (19.9%) meeting the following criteria: 1 tumor 2 to 3 cm, complete response after first LRT, and AFP ≤20 ng/mL after first LRT, had 1- and 2-year probabilities of dropout of 1.3% and 1.6%, respectively, compared to 21.6% and 26.5% for all other patients (p=0.004). In conclusion, a combination of tumor characteristics and complete response to the first LRT define a subgroup of patients with a very low risk of waitlist dropout who does not require the same listing priority. Our results may have important implications for the organ allocation policy for HCC.

Strategies to improve outcome of patients with hepatocellular carcinoma receiving a liver transplantation

“…However many LT institutions treat most of the patients within the waiting list, since the actual time to LT may be unpredictable, and this strategy has demonstrated a favourable cost-effect balance [73] . The radiological response to bridging therapy may also help to assess the HCC biological behavior [74][75][76] , and to prioritize HCC patients for LT [77][78][79][80][81] . Patients with tumour growth beyond Milan criteria after locoregional therapies should not undergo LT.…”

Standardizing MELD Exceptions: Current Challenges and Future Directions

“…HCC exception point recipients with a single tumor that has a complete response to loco-regional therapy and a low alpha-fetoprotein has exceedingly low risks of waitlist dropout, suggesting that these patients should receive fewer exception points or upgrades at longer intervals. 16 Second, the full impact of the growing number of HCC exception patients on the broader waitlist population is unknown. With increasing numbers of patients receiving exception points, the mean MELD score needed to receive an organ offer also continued to increase.…”

“…A patient with a single 2 cm HCC that responds well to loco-regional therapy would likely have a much different risk of tumor progression than a patient with three tumors, each 2cm in size, with persistent viability after two treatment cycles. 16 Yet both would be awarded the same number of points as each are within Milan criteria.…”

Liver graft allocation for hepatocellular carcinoma patients: Is a forced ablate-and-wait protocol nationally applicable?

“…In the original article, Mehta et al 2 identified a specific cohort of hepatocellular carcinoma (HCC) patients with T2 tumors whose risk of wait-list dropout was very low, and they suggested that such patients should not receive the same allocation advantage as higher risk groups (ie, those not meeting their criteria). In our editorial, we raised the issue of whether using such data to inform a new allocation algorithm might lead to worsening outcomes through the selection of recipients with a higher risk of tumor recurrence for liver transplantation (LT).…”