Spontaneous regression of hepatocellular carcinoma confirmed by surgical specimen: report of two cases and review of the literature

Spontaneous regression of lung metastases in hepatocellular carcinoma: A case report

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The prognosis of patients with advanced HCC remains poor even if appropriate treatments are administered.

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Spontaneous regression of lung metastases of hepatocellular is a rare condition.

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We discuss the mechanism for spontaneous regression of multiple pulmonary recurrences of hepatocellular carcinoma.

Introduction

Spontaneous regression of hepatocellular carcinoma (HCC) is a rare condition. However, although there have been multiple reports of spontaneous regression, the definitive pathogenic mechanism of this phenomenon is still unclear.

Case presentation

We encountered a case of a 78-year-old man who was undergoing dialysis for end-stage kidney disease with hepatitis C virus-associated chronic hepatitis presenting with HCC. The patient had previously undergone right lobectomy of the liver, but the cancer recurred with multiple lung metastases after 5 months. Approximately 13 months after the initial diagnosis of recurrence, the lung metastases decreased in size and eventually resolved without any anticancer therapy. The patient remains alive for over 41 months after recurrence.

Discussion

Based on our case and literature, Hypoxia with hypotension due to hemodialysis can reduce the blood and oxygen supply of the body, which may lead to the spontaneous regression of the metastatic tumors.

Conclusion

We herein reported a case of spontaneous regression of HCC undergoing dialysis.

Endogenous Molecular-Cellular Network Cancer Theory: A Systems Biology Approach

In light of ever apparent limitation of the current dominant cancer mutation theory, a quantitative hypothesis for cancer genesis and progression, endogenous molecular-cellular network hypothesis has been proposed from the systems biology perspective, now for more than 10 years. It was intended to include both the genetic and epigenetic causes to understand cancer. Its development enters the stage of meaningful interaction with experimental and clinical data and the limitation of the traditional cancer mutation theory becomes more evident. Under this endogenous network hypothesis, we established a core working network of hepatocellular carcinoma (HCC) according to the hypothesis and quantified the working network by a nonlinear dynamical system. We showed that the two stable states of the working network reproduce the main known features of normal liver and HCC at both the modular and molecular levels. Using endogenous network hypothesis and validated working network, we explored genetic mutation pattern in cancer and potential strategies to cure or relieve HCC from a totally new perspective. Patterns of genetic mutations have been traditionally analyzed by posteriori statistical association approaches in light of traditional cancer mutation theory. One may wonder the possibility of a priori determination of any mutation regularity. Here, we found that based on the endogenous network theory the features of genetic mutations in cancers may be predicted without any prior knowledge of mutation propensities. Normal hepatocyte and cancerous hepatocyte stable states, specified by distinct patterns of expressions or activities of proteins in the network, provide means to directly identify a set of most probable genetic mutations and their effects in HCC. As the key proteins and main interactions in the network are conserved through cell types in an organism, similar mutational features may also be found in other cancers. This analysis yielded straightforward and testable predictions on an accumulated and preferred mutation spectrum in normal tissue. The validation of predicted cancer state mutation patterns demonstrates the usefulness and potential of a causal dynamical framework to understand and predict genetic mutations in cancer. We also obtained the following implication related to HCC therapy, (1) specific positive feedback loops are responsible for the maintenance of normal liver and HCC; (2) inhibiting proliferation and inflammation-related positive feedback loops, and simultaneously inducing liver-specific positive feedback loop is predicated as the potential strategy to cure or relieve HCC; (3) the genesis and regression of HCC is asymmetric. In light of the characteristic property of the nonlinear dynamical system, we demonstrate that positive feedback loops must be existed as a simple and general molecular basis for the maintenance of phenotypes such as normal liver and HCC, and regulating the positive feedback loops directly or indirectly provides potential strategies to cure or relieve HCC.

Open-label Phase II clinical trial in 75 patients with advanced hepatocellular carcinoma receiving daily dose of tableted liver cancer vaccine, hepcortespenlisimut-L

Background

An increasing number of studies is now devoted to immunotherapy of cancer. We evaluated the clinical benefit of hepcortespenlisimut-L (Hepko-V5 [formerly known as V5])—an oral therapeutic vaccine designated by the United States Food and Drug Administration (FDA) as an orphan drug for treatment of hepatocellular carcinoma (HCC). V5 was initially developed by us in 2002 to treat hepatitis B or C viral infections and liver cirrhosis.

Methods

The outcome of open-label Phase II trial of daily dose of V5 pill was analyzed retrospectively. Over a period of 5 years, 75 patients with advanced HCC were enrolled, consisting of 29 (38.7%) females and 46 (61.3%) males with a median age of 60 years (mean 61.6±8.1 years). Out of these, 23 (30.7%) had hepatitis B and 34 (45.3%) had hepatitis C infections, including 9 (12%) with dual infection, 4 (5.3%) negative for both viruses, and 5 (6.7%) without established viral diagnosis. Most patients (94.7%) had underlying liver cirrhosis of varying severity.

Results

After a median of 2 months of treatment, 50 out of 75 patients had experienced a decline in serum levels of the tumor marker, alpha-fetoprotein (AFP) (66.7%; P=0.006 by Wilcoxon signed rank test). Baseline median AFP levels were 245.2 IU/mL (mean 4,233; range 7.2–92,407; 95% confidence interval [CI] 1,186–7,280) and post-treatment values were 102.3 IU/mL (mean 2,539; range 0.9–54,478; 95% CI 503–4,575). The decrease in AFP was correlated either with tumor clearance or regression on computed tomography scans. The median overall survival time could not be established since 68 out of 75 (90.7%) patients were still alive after median follow-up of 12 months (mean 15±9.7; range 7–59; 95% CI 12.8–17.2). The first patient in this study received immunotherapy 5 years ago and still remains in complete remission. None of the patients experienced any serious adverse effects or toxicity.

Conclusion

The results indicate that hepcortespenlismut-L is a safe, effective, and fast-acting immunomodulatory intervention for HCC. The Phase III, randomized, double-blind, placebo-controlled trial is now initiated at the Mongolian National Cancer Center to confirm these promising findings.

Spontaneous neoplastic remission of hepatocellular carcinoma

We report on a case of a 57-year-old male who underwent a curative resection for hepatocellular carcinoma (HCC) with histological confirmation of a spontaneously necrotized tumor. Initial serum AFP level was 4,778 ng/mL. A 3.7 cm hyperechoic mass in segment 6 of the liver was observed on ultrasonography and dynamic contrast-enhanced liver MRI showed a 3.7 × 3.1 cm sized HCC. He was scheduled to undergo curative surgical resection under the clinical diagnosis of an early stage HCC (Barcelona Clinic Liver Cancer stage A). Without treatment, the serum AFP level declined rapidly to 50 ng/mL over five weeks. He underwent curative wedge resection of segment 6 of the liver. Histology revealed complete necrosis of the mass rimmed by inflamed fibrous capsule on a background of HBV-related cirrhosis with infiltration of lymphoplasma cells. Exact pathophysiology underlying this event is unknown. Among the proposed mechanisms of spontaneous neoplastic remission of HCC, circulatory disturbance and activation of host immune response offer the most scientific explanation for the complete histologic necrosis of HCC in the resected mass seen in our patient.

Quantitative implementation of the endogenous molecular-cellular network hypothesis in hepatocellular carcinoma

A quantitative hypothesis for cancer genesis and progression-the endogenous molecular-cellular network hypothesis, intended to include both genetic and epigenetic causes of cancer-has been proposed recently. Using this hypothesis, here we address the molecular basis for maintaining normal liver and hepatocellular carcinoma (HCC), and the potential strategy to cure or relieve HCC. First, we elaborate the basic assumptions of the hypothesis and establish a core working network of HCC according to the hypothesis. Second, we quantify the working network by a nonlinear dynamical system. We show that the working network reproduces the main known features of normal liver and HCC at both the modular and molecular levels. Lastly, the validated working network reveals that (i) specific positive feedback loops are responsible for the maintenance of normal liver and HCC; (ii) inhibiting proliferation and inflammation-related positive feedback loops and simultaneously inducing a liver-specific positive feedback loop is predicated as a potential strategy to cure or relieve HCC; and (iii) the genesis and regression of HCC are asymmetric. In light of the characteristic properties of the nonlinear dynamical system, we demonstrate that positive feedback loops must exist as a simple and general molecular basis for the maintenance of heritable phenotypes, such as normal liver and HCC, and regulating the positive feedback loops directly or indirectly provides potential strategies to cure or relieve HCC.

Spontaneous massive necrosis of hepatocellular carcinoma with narrowing and occlusion of the arteries and portal veins

We herein present the case of a 77-year-old man who had fever and right hypochondriac pain. He visited his doctor and underwent contrast computed tomography (CT), and he was suspected to have a liver abscess. He received an antibiotic treatment and his symptoms soon disappeared, but the tumor did not get smaller and its density on contrast CT image got stronger. He underwent biopsy and moderately differentiated hepatocellular carcinoma (HCC) was found. Extended left hepatic and caudate lobectomy was performed. Histological examination showed moderately differentiated HCC with narrowing and occlusion both in the arteries and portal veins associated with mild chronic inflammation. The mechanisms of spontaneous regression of HCC, such as immunological reactions and tumor hypoxia, have been proposed. In our case, histological examination showed the same findings. However, the mechanism is complex, and therefore further investigations are essential to elucidate it.

Management considerations for purported spontaneous regression of hepatocellular carcinoma: a case report

Spontaneous regression of hepatocellular carcinoma (HCC) is an extraordinary phenomenon that occurs rarely. While more than 80 cases have been described, most have been established via radiological findings or examination of biopsy tissues rather than via pathological examination of a resected specimen. The present report describes a purported case of spontaneous regression of HCC as indicated by radiological examination. Subsequent immunostaining of surgically resected specimens revealed viable cancer cells, though only necrotic tissues were seen on hematoxylin and eosin staining. These data indicate that viable cancer cells may still be present even if imaging findings suggest spontaneous regression of HCC. Therefore, these patients should receive aggressive treatment similar to that used for patients with established HCC.

Spontaneous regression of hepatocellular carcinoma is most often associated with tumour hypoxia or a systemic inflammatory response

BACKGROUND

Spontaneous regression of hepatocellular carcinoma (HCC) is well documented, although the aetiology of this phenomenon remains unknown.

METHODS

A review of the English literature was performed for reports of spontaneous regression of HCC. Reports were classified by mechanism based on the available information.

RESULTS

Spontaneous regression of HCC has been identified in 75 patients. The most common mechanisms of regression identified were tumour hypoxia (n= 21, 28.0%), a systemic inflammatory response (n= 25, 33.3%) and unknown (n= 29, 38.7%). In patients where tumour hypoxia was described as the aetiology, mechanisms included spontaneous hepatic artery thrombosis and sustained systemic hypotension. In patients where a systemic inflammatory response was the aetiology, mechanisms included cholangitis, trauma and elevated cytokine levels.

DISCUSSION

Spontaneous regression of HCC is most commonly associated with tumour hypoxia or a systemic inflammatory response. Determining the aetiology of spontaneous regression may identify potential therapeutic pathways. Tumour hypoxia is already the basis of treatment modalities such as hepatic artery embolization and the anti-angiogenic agent sorafenib. However, treatment modalities for HCC do not currently include immune-directed therapies; this may prove to be a worthy target for future research.

Mechanisms underlying spontaneous regression of hepatocellular carcinoma

We searched MEDLINE and identified 85 cases of spontaneous regression of hepatocellular carcinoma (HCC). Analysis of these cases found that immunity is the most likely cause of spontaneous regression of HCC, and the elimination of immunosuppressive microenvironment may play a key role in this process. Ischemia, ethanol abstinence, and blood transfusion might lead to regression of HCC through the elimination of immunosuppression and activation of antitumor immunity.

Spontaneous regression of pancreatic cancer: Real or a misdiagnosis?

Spontaneous tumor regression has been subject of numerous studies and speculations for many years. This phenomenon is exceptional, but well reported, in some types of tumors, but not in pancreatic cancer. Pancreatic cancer has the worst five-year survival rate of any cancer. Despite numerous molecular studies and clinical approaches, using several mouse models, this cancer responds poorly to the existing chemotherapeutic agents and progress on treatment remains elusive. Although pancreatic cancer tumors seldom undergo spontaneous regression, and some authors take that with skepticism, there are some cases reported in the literature. However, the variability in the description of the reports and technical details could make this process susceptible to misdiagnosis. Distinguishing between different types of pancreatic carcinoma should be taken with caution as they have wide differences in malignant potential. Diseases such as pancreatic benign tumors, insulinomas, or autoimmune pancreatitis could be responsible for this misdiagnosis as a pancreatic cancer. Here we review different cases reported, their clinical characteristics, and possible mechanisms leading to spontaneous regression of pancreatic cancer. We also discuss the possibilities of misdiagnosis.

Spontaneous regression of hepatocellular carcinoma is possible and might have implications for future therapies

Hepatocellular carcinoma is a potentially challenging cancer with very high mortality. Medical therapies are generally ineffective in achieving complete remission, especially for aggressive types or for advanced stage cancers. Spontaneous regression of these tumors is a rare and fascinating phenomenon. We describe such a patient with spontaneous regression of a large multi-focal hepatocellular carcinoma, and present a comprehensive review of the reported cases with a special emphasis on potential regression mechanisms.

Vanishing liver tumours

Spontaneous resolution of liver tumours is a rare, but recognized entity that has been reported to occur within the spectrum of benign and malignant liver tumours occurring in both adult and paediatric population. The aetiology of this unusual phenomenon is not clearly understood. In this article we present case examples of various benign and malignant liver tumours that have regressed spontaneously without treatment together with a review of the literature, and a summary of the current understanding of the pathogenesis of these tumours.

Spontaneous regression of hepatocellular carcinoma: report of a case

A spontaneous regression of hepatocellular carcinoma is an extremely rare phenomenon. A 69-year-old Japanese man with hepatitis C virus-related chronic hepatitis presented with a liver tumor. We diagnosed the tumor to be hepatocellular carcinoma in the course of spontaneous regression, by imaging studies and changes in the tumor markers. Because the possible presence of viable cancer cells could not be ruled out, we recommended surgery. He refused all treatments at first, but finally agreed to undergo surgery about 10 months after presentation. A hepatectomy was performed. Histologically, no viable tumor cells were found. In our case, the vascularity of the tumor according to the imaging findings was followed up during the clinical course. The patient is now doing well and without any evidence of recurrence at 37 months after surgery.

Partial spontaneous regression of hepatocellular carcinoma: a case with high concentrations of serum lens culinaris agglutinin-reactive alpha fetoprotein

Spontaneous regression of hepatocellular carcinoma (HCC) is rare. There are few reports discussing spontaneous regression associated with serum lens culinaris agglutinin-reactive alpha fetoprotein (AFP-L3). We describe a case of HCC with a high level of AFP-L3, which showed a rapid increase in alpha fetoprotein (AFP) concentration after partial spontaneous regression, and which was then treated successfully. A 71-year-old woman suffering from chronic hepatitis C underwent surgical resection for HCC. Preoperative concentrations of AFP fluctuated; subsequent to a transient decrease, a rapid increase in AFP was observed. AFP-L3 concentration was extremely high. The resected tissue consisted of encapsulated moderately differentiated HCC, subcapsular coagulation necrosis, and chronic active hepatitis. The postoperative course was uneventful. At present, 24 months after diagnosis, no symptoms or signs of tumor recurrence or metastasis have been observed. Although the precise etiology of the spontaneous regression in this patient is not known, we speculate that spontaneous regression of tumor cells with high malignant potential may be related to arterial involvement and insufficient blood supply.

Two cases of spontaneous regression of multicentric hepatocellular carcinoma after intraperitoneal rupture: possible role of immune mechanisms

We report two cases of spontaneous regression of hepatocellular carcinoma. Firstly, a 64-year-old man with alcohol related cirrhosis developed multiple liver tumours with elevation of the alpha-fetoprotein level at 915 ng/ml. A spontaneous regression of all the tumoural masses but one and normalization of the alpha-fetoprotein level was observed after intraperitoneal spread of the malignancy. Resection of the remaining tumour 9 months later confirmed a hepatocellular carcinoma. Secondly, a 70-year-old woman with alcohol related cirrhosis developed multiple liver tumours with elevation of the alpha-fetoprotein level to 4000 ng/ml; a regression of all the tumoural masses but one and a decrease of the alpha-fetoprotein level to 400 ng/ml was observed after intraperitoneal spread of the malignancy and treatment with tamoxifen. We discuss a possible immune mechanism of tumoural regression with a review of similar cases described in the literature.

Hepatocellular carcinoma with an unusual medullary-like histology and signs of regression ("medullary-like hepatocellular carcinoma")

The case of a variant of hepatocellular carcinoma is described, which, based on its unique histology, we propose to term, medullary-like hepatocellular carcinoma. It developed in a 56-year-old male patient with liver cirrhosis, and consisted of large, amphophilic cells with a solid growth pattern. The tumour was densely infiltrated with lymphocytes and plasma cells. Lymphocytes formed a mixture of B and T cells, and plasma cells were polytypic. In addition, numerous S-100 protein-reactive stellate cells were observed at the tumour border, where marked apoptosis of hepatocellular carcinoma cells was evident. In areas of dense lymphoplasmacytic infiltration, part of the tumour cells had lost their intercellular connections and their beta-catenin reactivity. Some tumour cells expressed FasL, but not Fas. The tumour exhibited several foci of regression, showing small remnants of damaged tumour cells within dense infiltrations. The patient is alive without evidence of disease 25 months after resection. Medullary-like hepatocellular carcinoma is a lesion which mimics several features known for other medullary carcinomas, including a marked immune response which may be responsible for partial regression of this tumour.

CT demonstration of the spontaneous regression of a hypervascular lesion in cirrhotic liver

In patients with liver cirrhosis, arterial phase enhancement of nodular lesions on helical-CT is currently considered to be highly predictive of malignancy. We report the spontaneous regression of a hypervascular hepatic nodule in a patient with liver cirrhosis within 7 months demonstrated by helical-CT follow-up. This suggests that tumor angiogenesis known to be an obligatory step for acquisition of malignant properties could regress, and can be demonstrated by helical CT. Radiologists should be aware that CT detection of a hypervascular nodule in a cirrhotic liver is not always predictive of a malignant outcome.

Spontaneous regression of hepatocellular carcinoma and review of literature

A 68-year-old man presented with multiple hepatocellular carcinoma, which was considered to be unresectable at the first admission in January 1994. Pathological diagnosis was made by biopsy of the one lesion among them. From January 1994 to December 1997, 10 transarterial chemoembolizations and six percutaneous ethanol injection therapies were performed on the tumours in the cirrhotic liver. In February 1998 the tumour situated in the right lobe began to increase in size. The maximum tumour diameter was 6.3 cm measured by computed tomography (CT). In the beginning of May 1998 moderate ascites was present and mild hepatic encephalopathy was noticed. The patient was in the terminal stage of hepatocellular carcinoma and no further treatment was possible at that time. However, serum alpha-fetoprotein and protein induced by vitamin K absence or antagonist II dramatically decreased in June 1998. The CT scan also showed that the tumour had completely regressed without specific treatment. In February 1999 a new biopsy-proven hepatocellular carcinoma, 2 cm in diameter, developed in the lateral segment of the liver. It was well treated by percutaneous ethanol injection therapy. The patient was alive in good condition without any symptoms or tumour recurrence in June 1999. It was concluded that a rare case of spontaneous regression of hepatocellular carcinoma had occurred.