Abstract and Introduction
Abstract
The time that patients with hepatocellular carcinoma (HCC) can safely remain on the waiting list for liver transplantation (LT) is unknown. We investigated whether waiting time on the list impacts transplant survival of HCC candidates and transplant recipients. This is a single-center retrospective study of 283 adults with HCC. Patients were divided in groups according to waiting-list time. The main endpoint was survival. The median waiting time for LT was 4.9 months. The dropout rates at 3-, 6-, and 12-months were 6.4%, 12.4%, and 17.7%, respectively. Mortality on the list was 4.8%, but varied depending of the time on the list. Patients who waited less than 3-months had an inferior overall survival when compared to the other groups (p = 0.027). Prolonged time on the list significantly reduced mortality in this analysis (p = 0.02, HR = 0.28). Model for End Stage Liver Disease (MELD) score at transplantation did also independently impact overall survival (p = 0.03, HR = 1.06). MELD was the only factor that independently impacted posttransplant survival (p = 0.048, HR = 1.05). We conclude that waiting time had no relation with posttransplant survival. It is beneficial to prolong the waiting list time for HCC candidates without having a negative impact in posttransplant survival.
Introduction
Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide, with an estimated incidence of one million cases per year.
Liver transplantation (LT) has been utilized as a curative treatment for patients with HCC. In countries where the liver allograft allocation is based on the Model for End-Stage Liver Disease (MELD) system, patients with HCC within the Milan criteria (MC) are awarded with exception points, which are adjusted over time to prevent dropout of the list.
Recently, there have been critiques on the quantity of exception points granted to HCC patients when compared with non-HCC patients. To address this particular inequity of the MELD system, the United Network for Organ Sharing (UNOS) is now considering delaying the HCC MELD exception points. Preliminary data of the Liver and Intestine UNOS Committee have shown that a 6-month delay in receiving an HCC MELD exception would result in a nearly equal transplant rate for HCC and non-HCC recipients.
However, the amount of time that HCC patients can safely remain waiting for LT is yet unknown and has also been a topic of controversy. Some experts have suggested the utilization of living donation to shorten waiting time. This "fast-tracking" approach would allow transplantation of tumors that would have been selected out with longer waiting list time. Other groups believe that an observation period is crucial to evaluate tumor biology while patients wait on the list. The "ablate-and-wait" strategy utilizes neoadjuvant therapy during this assessment period. Based on this premise, Chao et al found no direct impact of waiting time on LT outcomes.
The state of São Paulo (in Brazil) has a population of 42 million habitants with more than 15 liver transplant centers. To have prompt access to LT, recipients must have a high score (MELD >30). Thus, candidates with HCC face a prolonged waiting time that averages consistently over 6-months. We hypothesize that a prolonged waiting list time does not jeopardize overall and posttransplant survival among HCC patients that successful reach transplant. The aim of this manuscript if to verify whether waiting time impacts transplants survival of HCC candidates and transplant recipients.