Hepatocellular carcinoma locoregional therapies for patients in the waiting list. Impact on transplantability and recurrence rate.

The practice of treating candidates to liver transplantation (LT) for hepatocellular carcinoma (HCC) with locoregional therapies is common in most transplant centers. However, for T1 tumors and expected waiting times to LT <6 months, there is no evidence that these treatments are beneficial. For T2 tumors and for longer waiting times, neo-adjuvant treatments are usually performed with transarterial chemoembolization (TACE), ablation techniques, and liver resection in selected cases. The treatment choice should be based on the BCLC staging system. At present, there is no evidence of the superiority of ablation/resection vs. TACE, but some studies showed better results of the former in achieving a complete response. The response to neo-adjuvant treatments should be evaluated through mRECIST criteria, but few studies adopted these criteria and properly analyzed factors affecting response. The simultaneous evaluation of the impact of neo-adjuvant therapies on dropout rate, post-LT HCC recurrence and patient survival is rarely reported. Tumor stage and volume, alpha-fetoprotein levels, response to treatments and liver function affect pre-LT outcomes. These same factors, together with vascular invasion and poor tumor differentiation are major determinants of poor post-LT outcomes. Due to the low number of prospective studies with well defined entry criteria and the variability of results, the role of downstaging is still to be defined. Novel molecular markers seem promising for the estimation of prognosis and/or response to treatments. With a persistent scarcity of organ donors, neo-adjuvant treatments can help in identifying patients with different probabilities of cancer progression, and consequently in balancing the priority of HCC and non-HCC-candidates through revised additional scores for HCC.