Locoregional Therapies for Bridging and Downstaging Hepatocellular Carcinoma Prior to Liver Transplant

Abstract

Hepatocellular carcinoma is the most common primary liver malignancy and is a common indication for liver transplantation. To qualify for liver transplantation, the size and number of tumors must be within established criteria. The Milan criteria is the most well-established of these criteria, however there is evidence these criteria can be safely expanded without affecting outcomes. While awaiting liver transplantation, locoregional therapy can be used as bridging therapy to maintain the tumor burden within criteria. Locoregional therapy can also be used to decrease tumor burden within transplant criteria, a process called downstaging. For tumors <3 cm, thermal ablation-most commonly using a radio-frequency probe-is preferred when feasible and offers tumor control approaching that of resection. Larger or multifocal lesions are usually treated with either trans-arterial chemoembolization or yttrium-90 trans-arterial radioembolization. The choice between these two interventions is generally based on institutional preference as neither has demonstrated survival advantage in the transplant population. However, single center trials show longer time to progression, improved downstaging success, and less microvascular invasion in patients treated

Microwave ablation as a primary versus secondary treatment for hepatocellular carcinoma

“…MWA is usually preferred in patients with smaller tumors in favorable locations away from major anatomical structures, such as the dome of the liver, gallbladder, or biliary system. 17 The choice of therapy is also essentially operator and institution depend- Recent studies have evaluated the efficacy and safety of new systemic antineoplastic therapies (atezolizumab/bevacizumab) compared with conventional first-line treatment with sorafenib in patients with unresectable HCC, demonstrating significantly increased OS and PFS rates. 31,32 However, to our knowledge, no studies have been conducted comparing the clinical outcomes and disease prognosis associated with the use of local ablative treatments and these newer chemotherapeutic agents in HCC.…”

“…MWA is usually preferred in patients with smaller tumors in favorable locations away from major anatomical structures, such as the dome of the liver, gallbladder, or biliary system. 17 The choice of therapy is also essentially operator and institution dependent. A recent study by Chen et al 30 studied patients with intermediate-stage HCC who were refractory to TACE and compared the OS and RFS of MWA vs. sorafenib as salvage therapy.…”

“…Many studies have shown similar outcomes between first-line RFA and microwave ablation (MWA), especially with lesions of less than 3 cm. 16 , 17 One meta-analysis looked at five original studies comparing RFA and MWA outcomes in 431 patients. 18 In a patient population of very early- or early-stage HCC [Barcelona Clinic Liver Cancer (BCLC)] (stage 0 or A), they found no differences in complete ablation rates, recurrence-free survival (RFS), overall survival (OS), or complication rates.…”

“…The average ablation time for MWA was significantly shorter than for RFA. 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 In most centers in the USA, MWA has replaced RFA for treating HCC. The purpose of this study was to compare treatment outcomes of MWA in naïve tumors with those with residual or recurrent disease following TACE or transarterial radioembolization (TARE).…”

Threatment Strategies for Recurrent Hepatocellular Carcinoma Patients: Ablation and its Combination Patterns

“…In appropriately selected (<3-5cm) patients, ablative therapy has resulted in 5-year overall survival rates of 26% to 71% and can be used in patients with combined portal hypertension 14 . For early intrahepatic recurrence, repeat hepatic resection and ablation have similar efficiency rates as Transarterial chemoembolization (TACE), and repeat hepatic resection and ablation are the treatment of choice for patients with advanced recurrence after radical resection for HCC meeting the Milan criteria, whereas ablation therapy can also be used for bridging or descending prior to surgery or transplantation 15 . The overall survival of patients with rHCC after repeat hepatectomy and ablation is similar to that of patients with primary tumor resection 16 .…”