Proton beam therapy to bridge or downstage locally advanced hepatocellular carcinoma to living donor liver transplantation

Liver transplantation and resection in patients with hepatocellular cancer and portal vein tumor thrombosis: Feasible and effective?

Patients with locally advanced hepatocellular cancer (HCC) and portal vein tumor thrombosis (PVTT) have a dismal prognosis since limited treatment options are available for them. In recent years, effective systemic therapy, and advances in the understanding of technicalities and effectiveness of ablative therapies especially radiotherapy, have given some hope to prolong survival in them. This review summarized recent evidence in literature regarding the possible role of liver resection (LR) and liver transplantation (LT) in patients with locally advanced HCC and PVTT with no extrahepatic disease. Downstaging therapies have helped make curative resection or LT a reality in selected patients. This review emphasizes on the key points to focus on when considering surgery in these patients, who are usually relegated to palliative systemic therapy alone. Meticulous patient selection based on tumor biology, documented downstaging based on imaging and decrease in tumor marker levels, and an adequate waiting period to demonstrate stable disease, may help obtain satisfactory long-term outcomes post LR or LT in an intention to treat strategy in patients with HCC and PVTT.

Are patients with hepatocellular carcinoma and portal vein tumour thrombosis candidates for liver transplantation?

In this debate, the authors consider whether patients with hepatocellular carcinoma (HCC) and portal vein tumour thrombosis are candidates for liver transplantation (LT). The argument for LT in this context is based on the premise that, following successful downstaging treatment, LT confers a much greater clinical benefit in terms of survival outcomes than the available alternative (palliative systemic therapy). A major argument against relates to limitations in the quality of evidence for LT in this setting - in relation to study design, as well as heterogeneity in patient characteristics and downstaging protocols. While acknowledging the superior outcomes offered by LT for patients with portal vein tumour thrombosis, the counterargument is that expected survival in such patients is still below accepted thresholds for LT and, indeed, the levels achieved for other patients who receive transplants beyond the Milan criteria. Based on the available evidence, it seems too early for consensus guidelines to recommend such an approach, however, it is hoped that with higher quality evidence and standardised downstaging protocols, LT may soon be more widely indicated, including for this population with high unmet clinical need.

Liver transplantation and portal vein tumour thrombus: futile enterprise?

PURPOSE OF REVIEW

To summarize recent evidence in literature regarding liver transplantation in patients with hepatocellular carcinoma (HCC) and portal vein tumour thrombosis (PVTT) with no extrahepatic disease. In addition, in this review, we have tried to highlight the advances in downstaging with ablative therapies that have made liver transplantation a possibility, and also the key points to focus on when considering liver transplantation in these patients with locally advanced HCC.

RECENT FINDINGS

Advances in the understanding of technicalities and effectiveness of ablative therapies, including transarterial chemoembolization, stereotactic body radiotherapy and transarterial radioembolization on PVTT have helped successfully downstage patients with HCC and PVTT to within transplant criteria. This provides the opportunity to offer a curative liver transplantation in these patients who are generally managed with systemic or palliative therapy alone with dismal prognosis. Meticulous patient selection based on tumour biology, documented downstaging based on imaging and decrease in tumour marker levels, an adequate waiting period to demonstrate stable disease, liver transplantation with some technical modifications, and a modified immunosuppression protocol may offer long-term survival in a select group of patients treated with initial downstaging therapies in an intention to treat strategy.

SUMMARY

In patients with HCC, presence of PVTT is generally considered the end of the road by many. A multidisciplinary approach combining ablation and a curative liver transplantation may offer the best hope of long-term survival in a select group of patients with favourable tumour biology. Although promising, current evidence is limited, and future studies with larger number of patients, and longer follow-up may pave the way for an elaborate selection algorithm to choose the ideal candidates for such a curative strategy in patients with locally advanced HCC with PVTT.

Proton Beam Therapy for Multifocal Hepatocellular Carcinoma (HCC) Showing Complete Response in Pathological Anatomy After Liver Transplantation

We describe a patient with multifocal recurrent hepatocellular carcinoma (HCC) who received proton beam therapy (PBT) and then underwent donation after brain dead (DBD) liver transplantation. The anatomy of the explanted diseased liver was examined pathologically post-transplantation. The patient was a 52-year-old male with hepatitis B virus infection and liver cirrhosis of Child-Pugh class B. Right lobe and caudate lobectomy were performed for primary HCC. However, three recurrent tumors appeared in the remnant liver in segments S2 (two sites) and S4, of sizes 23 mm, 10 mm, and 32 mm, respectively. Liver transplantation was required due to these multiple HCCs and liver cirrhosis, but the patient was ineligible for living donor liver transplantation (LDLT) based on Milan criteria. He was registered as a candidate on the waiting list for DBD transplantation. In consideration of the long waiting time for a deceased donor transplant for more than one year, the progression of multiple recurrent HCCs, and the risk of death, the patient had limited treatment options other than PBT for poor liver function and multifocal HCC and eventually received 65 GyE/18 fractions of PBT. Eleven months after the start of PBT, the tumors remained progression-free and liver function did not deteriorate, allowing the patient to wait for liver transplantation. After transplantation, the histopathology of the explanted liver showed that the left lobe of the liver treated by PBT showed no evidence of solid tumors and tumor cells in visual and microscopic examinations. There was also no significant damage to normal liver tissue. This case demonstrates that PBT is a prospective option for patients with HCC with poor liver function, multiple tumors, and no other treatment options. PBT can achieve control or even complete response of HCC while maintaining liver function and may be an effective pre-transplant method for tumor downstaging and prolonging survival. PBT may enable more people to wait for a donor liver or to become eligible for liver transplantation.