The clue of a possible etiology about spontaneous regression of hepatocellular carcinoma: a perspective on pathology

Spontaneous vanishing of hepatocellular carcinoma: A case report of an extremely rare incident

One of the very uncommon clinical conditions is the spontaneous remission of tumors, with scarce reports around the world in various types of tumors. Spontaneous remission of hepatocellular carcinoma (HCC) is extremely rare, but it is well documented with a still unclear underlying mechanism. In this case report, we present one of those exceptional incidents of HCC regression with a trial to tackle possible explanations. Our case, which has a history of successfully treated hepatitis C virus, presented with a large infiltrative right lobar mass invading the main portal vein, with markedly elevated alpha fetoprotein (AFP). According to the applied diagnostic and treatment guidelines, the patient was scheduled for conservative management. Although he did not receive any specific treatments for his condition, the mass regressed in size with recanalization of the portal vein and normalization of AFP after 6 months of follow-up and keep the same for the following 3 years. The mechanisms by which spontaneous regression of HCC can occur are still unknown and should be furtherly investigated better to understand the behavior of such aggressive neoplastic disease.

Vanishing Tumor in a Liver Graft from a Hepatitis B Virus Surface Antigen-Positive Donor

We report a case of vanishing tumor considered as inflammatory pseudotumor (IPT) found in the liver after living donor liver transplantation (LDLT) from a hepatitis B virus surface antigen-positive donor. The radiological findings were similar to those of hepatocellular carcinoma (HCC). However, the tumor disappeared completely within several months and was suggested to have been an IPT. IPT is known to be associated with biliary duct operation or biliary infection, and it can show various enhancement patterns in radiological studies, sometimes resembling HCC. It should be considered in the differential diagnosis of a liver tumor in patients with LDLT.

Spontaneous regression of hepatocellular carcinoma: A mini-review

Spontaneous tumor regression is an extremely rare phenomenon in the oncology field. However, there are several case reports resulted in the regression of hepatocellular carcinoma (HCC) and the accumulation of clinical information and analyses of the mechanism can contribute to the development of a novel therapy. For this purpose, we have carefully reviewed 23 cases of spontaneously regressed HCC published in recent 5 years and our case. The information regarding the tumor size, tumor marker, treatments, etc., have been summarized. The mechanism of spontaneous regression has been discussed to date and presumed to be due to many factors, including hypoxia and immunological reactions. In this careful review of the 24 cases based on the clinical information, hypoxia, systemic inflammation, and both upon spontaneous regression were seen in 3, 8, and 4 cases, respectively among the 15 cases for which the information regarding the proposed mechanisms are available. Recent development of immunotherapeutic approaches in oncology shows promising results, therefore, accumulation of additional cases and analysis of mechanisms underlying the spontaneous regression of HCC are essential and could lead to the development of a new generation of immunotherapies including antibodies directed against immune reactions.

Role of regorafenib as second-line therapy and landscape of investigational treatment options in advanced hepatocellular carcinoma

Sorafenib is still the only systemic drug approved for the treatment of advanced hepatocellular carcinoma (HCC). In recent years, several investigational agents mainly targeting angiogenesis failed in late-phase clinical development due to either toxicity or lack of benefit. Recently, data of the RESORCE trial, a placebo-controlled Phase III study that evaluated the efficacy and safety of regorafenib in patients with HCC and documented disease progression after systemic first-line treatment with sorafenib, were presented at the ESMO World Congress on Gastrointestinal Cancer, 2016. Regorafenib treatment resulted in a 2.8-month survival benefit compared to placebo (10.6 months vs 7.8 months). Side effects were consistent with the known profile of regorafenib. The approval of regorafenib for this indication is expected in 2017. Further candidate agents in Phase III evaluation for second-line treatment of patients with HCC are the MET inhibitors tivantinib and cabozantinib, the vascular endothelial growth factor receptor-2 antibody ramucirumab, and the programmed death receptor-1 (PD-1) blocking antibody pembrolizumab. Furthermore, results from two first-line trials with either the tyrosine kinase inhibitor lenvatinib or the PD-1 antibody nivolumabin in comparison to sorafenib are awaited in the near future and might further change the treatment sequence of advanced HCC.

Novel drugs in clinical development for hepatocellular carcinoma

INTRODUCTION

Sorafenib is the only systemic drug approved for the treatment of advanced hepatocellular carcinoma (HCC). Within recent years, several investigational agents mainly targeting angiogenesis failed in late-phase clinical development either due to toxicity or lack of benefit.

AREAS COVERED

This review covers recent clinical data on systemic agents and ongoing trials in patients with advanced HCC.

EXPERT OPINION

In unselected patients with advanced HCC, disappointing results have been reported from several large trials. However, in two subgroups encouraging results have been achieved. Treatment with the MET inhibitor tivantinib resulted in a substantial survival benefit in the subgroup of MET overexpressing tumors in a randomized Phase II trial. Furthermore, the vascular endothelial growth factor receptor 2 antibody ramucirumab resulted in improved overall survival in patients with baseline α-fetoprotein (AFP) ≥ 400 ng/ml in a Phase III trial. These two agents, and several others, will be further developed in HCC. Moreover, immunotherapeutics such as checkpoint inhibitors, programmed death receptor-1 blocking antibodies and oncolytic viruses are under investigation in advanced HCC.