Fibrolamellar hepatocellular carcinoma: prolonged survival with multimodality therapy

Response to systemic treatments and survival of fibrolamellar carcinomas: An AGEO-SFCE French multicenter retrospective cohort

INTRODUCTION

Fibrolamellar carcinomas (FLC) are rare and predominantly advanced hepatic malignancies, lacking a clear consensus on anti-tumor treatments (ATT). The primary objective of the study was to determine whether any ATT appeared to give favorable outcomes in terms of morphological objective response (ORR) and disease control (DCR) rate according to RECIST 1.1 criteria.

PATIENTS AND METHODS

This retrospective multicentric French cohort from 14 centers included 44 patients with histologically proven FLC who received at least one ATT (chemotherapy and/or tyrosine kinase inhibitors, TKI) and underwent at least one morphological evaluation. .

RESULTS

A total of 40 anti-tumor responses were analyzed after a first line treatment. No complete response was observed, with an ORR in 13 % of cases, a DCR in 55 % of cases and 45 % of disease progression. GEMOX regimen (n = 9) showed an ORR of 11 % and a DCR of 33 %; the combination of doxorubicin and platinum-based chemotherapy (n = 6) achieved an ORR of 33 % and a DCR of 83 %. For TKI, sorafenib (n = 10) and sunitinib (n = 3), there was no objective response, with a DCR of 40 % and 33 % respectively. The median and the 5-years overall survival were 3.3 years and 35 % (95 %CI=[0.23-0.54]) respectively.

CONCLUSION

FLC have a poor prognosis; ATT show mild response rate. Further approaches and personalized medicine seem to be an unmet need for patients with FLC and new treatments should be urgently developed.

How Do I Diagnose Fibrolamellar Carcinoma?

Fibrolamellar carcinoma (FLC) is a unique primary carcinoma of the liver that is characterized by distinct morphologic findings and a recurrent DNAJB1::PRKACA gene fusion. It typically presents in young individuals without underlying liver dysfunction. FLC is difficult to diagnose when based only on morphology, and misdiagnosis is common. Frequent differential diagnoses include conventional hepatocellular carcinoma and intrahepatic cholangiocarcinoma, both of which can show similar morphologic and immunohistochemical features. If based only on molecular analysis, other differential diagnoses have recently emerged, as the DNAJB1::PRKACA fusion has now been reported in cases of intraductal oncocytic papillary neoplasm and intraductal papillary mucinous neoplasm. In this article, we review our diagnostic approach to FLC, which relies on both morphologic and immunohistochemical features, as well as molecular analysis.

Treatment Outcomes in Patients with Advanced Fibrolamellar Hepatocellular Carcinoma Under Systemic Treatment: Analysis of Clinical Characteristics, Management, and Radiomics

Purpose

Fibrolamellar hepatocellular carcinoma (FLHCC) is a rare primary liver malignancy often diagnosed at advanced stages. While there are limited data on the efficacy of specific agents, we aim to report outcomes of patients treated with systemic therapies and explore prognostic factors.

Patients and Methods

Medical records of patients treated between 2010 and 2022 were reviewed. Treatments were defined after multidisciplinary assessment. Descriptive statistics were used for baseline demographics. Time-to-event outcomes were estimated using the Kaplan-Meier method, compared by log-rank and adjusted by a regression model. Radiomic features (including size, shape, and texture) of the primary lesion were extracted and dimensionality reduced. An unsupervised Gaussian Mixture Model (GMM) clustering was performed, and survival was compared between clusters.

Results

We identified 23 patients: 12 males, with a median age of 23.6 years. At diagnosis, 82.6% had metastases, most frequently to the lungs (39.1%), lymph nodes (39.1%), and peritoneum (21.7%). Patients received a median of three lines (1-8) of treatment, including different regimens. Sorafenib (39.1%), capecitabine (30.4%), and capecitabine/interferon (13%) were the most used first-line regimens. The median time-to-failure was 3.8 months (95% CI: 3.2-8.7). Capecitabine + interferon (42.1%) and platinum combinations (39.1%) were the most used second-line regimens, with a time-to-failure of 3.5 months (95% CI: 1.5-11.6). Median overall survival was 26.7 months (95% CI: 15.1-40.4). A high baseline neutrophil-to-lymphocyte ratio (NLR) was associated with worse survival (p=0.02). Radiomic features identified three clusters, with one cluster (n=6) having better survival (40.4 vs 22.6 months, p=0.039). Tumor sphericity in the arterial phase was the most relevant characteristic associated with a better prognosis (accuracy=0.93).

Conclusion

FLHCC has unique features compared to conventional HCC, including young onset, gender balance, and absence of hepatopathy. Systemic therapies can provide encouraging survival, but lack of uniformity precludes defining a preferable regimen. Radiomics and NLR were suggested to correlate with prognosis and warrant further validation.

Exploring the molecular pathogenesis, diagnosis and treatment of fibrolamellar hepatocellular carcinoma: A state of art review of the current literature

This paper aims to present a detailed overview of fibrolamellar carcinoma (FLC), a variant of hepatocellular carcinoma (HCC) that accounts for approximately 1-9% of all cases a. according to the SEER database. Despite ongoing research, the aetiology of FLC tumours remains unclear. Nevertheless, FLC is believed to have a better overall prognosis than other primary liver tumours, such as hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma. This study aims to present a comprehensive overview of fibrolamellar carcinoma (FLC), with a focus on its epidemiology, pathogenesis, diagnosis, treatment, and prognosis. FLC frequently incorporate features of stomach pain, weight loss, and malaise in their clinical signs and symptoms, which are generally nonspecific Ultimately, the most common physical finding is an abdominal mass or hepatomegaly. With this said, several unusual presentations have been documented such as Budd Chiari syndrome, severe anaemia, non-bacterial thrombotic endocarditis and many more. In regards to this tumour's genetic analysis, it is characterised by a 400 kb deletion on chromosome 19 leading to a functional DNAJB1-PRKACA chimeric transcript in addition to tetraploidy in 50% of cases. FLC is chromosomally stable as compared to typical HCC. mTOR pathway activation has also been found to play a critical role in 47% of these tumours and EFGR over-expression is also evident. Fibrolamellar carcinomas (FLCs) exhibit a distinctive gross appearance, characterized by a yellow to pale tan colour, with a consistency that can vary from soft to firm and hard. In addition, a central scar is observed in 60-70% of FLC cases. The central scar is typically white or grey in colour and has a fibrous appearance, which is often surrounded by nodular, tumour-like tissue. Its histologic appearance is characterized by large polygonal cells with abundant eosinophilic cytoplasm, large vesiculated nuclei, large nucleoli, and arranged in lamellar bands of collagen fibres. Lamellar bands of fibrosis, consisting of collagen type I, III and IV, have also been identified as a distinctive histologic feature that is observed under low power magnification. Ultrasound, CT and MRI along with image guided biopsy are the primary modalities in diagnosis. Current management options include systemic therapy which has thus far been unremarkable with platinum-based therapies as well combination therapy with interferon alpha-2b being the most successful options. Surgical resection remains the primary treatment modality and there have been no advances in targeted therapies. Although the prognosis for FLC is favourable as compared to other hepatic cancer subtypes such as intrahepatic cholangiocarcinoma, there is a high rate of recurrence ranging from 33% to 100% with a median recurrence-free survival of 20-48 months. As a result of this there is a low overall cure rate associated with this tumour type and much more research is required to gain an in-depth understanding of the molecular mechanisms occurring in order to provide more adequate treatment to patients who suffer from this condition.

A Multidisciplinary Approach to the Management of Fibrolamellar Carcinoma: Current Perspectives and Future Prospects

Fibrolamellar carcinoma (FLC) is a rare primary liver tumor affecting predominantly younger and otherwise healthy patients. Typically, FLC presents with advanced disease due to the paucity of typical symptoms and no history of underlying liver disease. Depending on tumor characteristics and the patient's general condition, surgical treatment is the most promising treatment modality. Aggressive resection and liver transplantation have been utilized and are presently indispensable curative treatment options. Under certain circumstances surgical resection is also possible for metachronous metastases or local recurrence. Recent tumor biology discoveries have contributed to improved diagnostic specificity and systemic treatment options.

Fibrolamellar hepatocellular carcinoma: A rare but unpleasant event

Fibrolamellar carcinoma (FLC) is a rare variant of hepatocellular carcinoma (HCC), comprising 1%-9% of all HCCs. FLC is a poorly understood malignancy, which seems to be more prevalent in young patients with no underlying liver diseases. The term "fibrolamellar" is derived from thick fibrous collagen bands surrounding the tumor cells. Unlike HCC, cirrhosis and viral hepatitis infection are not predisposing to FLC, and it is not associated with elevations in serum alpha-fetoprotein. FLC patients often present with vague abdominal pain, nausea, malaise, and weight loss. Most cases present are at an advanced stage at the time of initial diagnosis. However, curative treatment options can still be offered to up to 70% of patients. Surgery (resection/liver transplantation) is the mainstay of treatment and the only potentially curative option. FLCs have been less chemo-responsive than the conventional HCC, however, in advanced cases, multimodality treatments can be effective. Recent advances in molecular studies of FLC have found a unique DNAJB1-PRKACA fusion transcript in most of the cases studied. The review aims to describe clinical characteristics, diagnostic methods, and therapeutic modalities for this rare tumor to raise awareness among clinicians and surgeons.

Liquid-liquid phase separation: a principal organizer of the cell's biochemical activity architecture

Numerous processes occur simultaneously in the cell both for normal function and in response to changes in the environment. The ability of cells to segregate biochemical reactions into separate compartments is essential to ensure specificity and efficiency in cellular processes. The discovery of liquid-liquid phase separation as a mechanism of compartmentalization has revised our thinking regarding the intracellular organization of molecular pathways such as signal transduction. Here, we highlight recent studies that advance our understanding of how phase separation impacts the organization of biochemical processes, with a particular focus on the tools used to study the functional impact of phase separation. In addition, we offer some of our perspectives on the pathological consequences of dysregulated phase separation in biochemical pathways.

Fibrolamellar carcinoma: An entity all its own

Fibrolamellar carcinoma (FLC) is a rare malignant entity arising from the liver and primarily affecting patients in late adolescence and young adulthood. FLC tumors are characterized by their unique histologic features and an only recently discovered genomic alteration: a chimeric fusion protein found in nearly all tumors. The rarity of these tumors coupled with the only recent acknowledgement of this genomic abnormality has likely led to disease under-recognition and de-prioritization of collaborative efforts aimed at establishing an evidence-guided standard of care. Surgical resection undoubtedly remains a mainstay of therapy and a necessity for cure but given the incidence of metastatic disease at diagnosis and high rates of distant relapse, systemic therapies remain a key component of disease control. There are few systemic therapies that have demonstrated proven benefit. Recent efforts have galvanized around single-institute or small consortia-based studies specifically focused on the enrollment of patients with FLC or use of agents with biologic rationale. This review will outline the current state of FLC epidemiology, histology, biology and trialed therapies derived from available published literature.

Pediatric fibrolamellar hepatocellular carcinoma: case report and review of the literature

BACKGROUND

A 13-year-old boy presented with acute abdominal pain in the right upper quadrant without previous trauma. Abdominal ultrasound (US) revealed a mass in the right liver lobe with free intraperitoneal fluid, suggestive for hemoperitoneum. Magnetic resonance imaging confirmed a subcapsular lesion (5.7 × 4.6 × 4.1 cm), suggestive for fibrolamellar hepatocellular carcinoma (FL-HCC). Positron emission tomography-computed tomography revealed mild to moderate fluorodeoxyglucose (FDG) avidity, with no other FDG avid lesions. Hepatic tumor markers were negative.

CASE REPORT

An elective right hepatectomy with cholecystectomy and hilar lymph node resection was performed.

RESULTS

Histology showed a central fibrous scar and confirmed a FL-HCC (pT1bN0M0). The resected lymph nodes were tumor-free. Treatment of FL-HCC should consist of complete tumor resection with concurrent lymph node resection +/- orthotopic liver transplantation. Long-term follow-up is advised. A follow-up interval of 3-4 months in the first 2 years after surgical resection can be justified as FL-HCC have a high recurrence rate of more than 50% within 10-33 months.

CONCLUSIONS

Malignancy can be a rare cause of abdominal pain in pediatric patients. An abdominal US is essential to prevent misdiagnosis. Treatment of FL-HCC should consist of R0 tumor resection with concurrent lymphadenectomy +/- orthotopic liver transplantation.

Fibrolamellar hepatocellular carcinoma treated with atezolizumab and bevacizumab: two case reports

Background

Fibrolamellar hepatocellular carcinoma is a unique tumor of the liver that differs from the classical hepatocellular carcinoma in diagnosis, behavior, and possibly treatment. There is usually absent underlying liver disease, and it usually occurs in young patients. The survival outcomes in localized fibrolamellar hepatocellular carcinoma are perhaps better than in classical hepatocellular carcinoma if treated early and radically. On the other hand, the prognosis remains poor for locally advanced and metastatic fibrolamellar hepatocellular carcinoma. Many reports suggested a limited benefit from systemic chemotherapy. Sorafenib also did not show major effects on fibrolamellar hepatocellular carcinoma. Given the rarity of fibrolamellar hepatocellular carcinoma, lack of large studies, and absence of standard treatment, the treatment decisions rely on case reports, previously reported cases series, and expert opinions. Recent studies have shown promising effects of immunotherapy with checkpoint inhibitors in the first- and second-line therapy of hepatocellular carcinoma. Atezolizumab with bevacizumab regimen has been approved recently as a first-line treatment for classical hepatocellular carcinoma. Currently, there are no reports yet on the use of atezolizumab with bevacizumab for fibrolamellar hepatocellular carcinoma.

Case report

In this article, we present two Arabic patients with advanced fibrolamellar hepatocellular carcinoma who received atezolizumab and bevacizumab combinations but did not show any clinical benefits.

Conclusion

While atezolizumab and bevacizumab combinations had shown benefits in classical hepatocellular carcinoma, the current data showed a lack of benefit and tumor response in fibrolamellar hepatocellular carcinoma.

Early Experiences with Triple Immunochemotherapy in Adolescents and Young Adults with High-Risk Fibrolamellar Carcinoma

INTRODUCTION

There are no standard systemic therapies for the treatment of fibrolamellar carcinoma (FLC), as surgery remains the only definitive option. We share our experiences using systemic "triple therapy" (TT) with 5-fluorouracil, interferon, and nivolumab for the treatment of relapsed, refractory, metastatic, or unresectable FLC.

METHODS

Data from all patients who received TT from May 2018 to July 2020 were reviewed to assess response, survival, and toxicity.

RESULTS

A total of 22 patients were treated with TT, of which 14 (median age of 21 years) were evaluable. They received a median of 18 cycles (8-44). At the time of analysis, the median progression-free survival was 9 months (4.5-26), 29% longer than prior to TT, with 5 patients achieving clinical remission, 8 patients stable or improving, and 1 progression. Overall objective response (clinical remission + partial response) was 50% and tumor control rate (clinical remission + partial response + stable disease) was 93%. Two patients withdrew from treatment due to side effects.

DISCUSSION/CONCLUSION

Our early results support TT as a promising medical option to slow disease progression and prolong survival in high-risk patients with FLC. TT can be administered in the outpatient setting and has shown good tolerability. Further longitudinal data is needed to confirm outcomes, especially in patients still early in their treatment.

Management of Diagnosis and Treatment in a Case of Fibrolamellar Carcinoma

BACKGROUND/AIM

Fibrolamellar carcinoma is a rare primary hepatic malignancy that has recently been recognized as a distinct clinical entity, highly different from the well-known hepatocellular carcinoma. This report describes the clinical and paraclinical aspects of the fibrolamellar carcinoma, emphasizing its particularities.

CASE REPORT

A 30-year-old patient presented to the hospital with nonspecific symptoms and weight loss, with imaging findings showing abdominal and mediastinal masses. Multiple biopsies were performed, leading to a diagnosis of metastatic fibrolamellar carcinoma. Given the extent of the disease, systemic drug treatment was administered, although prognosis was poor with tumor growth, resulting in biliary duct invasion.

CONCLUSION

Fibrolamellar carcinoma is a rare type of malignancy, with a difficult differential diagnosis in which imaging techniques are important but for which biopsy remains the gold standard. The prognosis depends on tumor extent and may include surgical methods or chemotherapy.

Systemic therapy of liver cancer

Hepatocellular carcinoma (HCC) is a lethal malignancy with poor prognosis. More than 80% of patients are diagnosed at an advanced stage, and most patients with HCC also have liver cirrhosis that complicates cancer management. No targeted treatment options currently exist outside genomics-based clinical trials. Multiple tyrosine kinase inhibitors (mTKIs) such as sorafenib, lenvatinib, cabozantinib, and regorafenib have been used to treat advanced hepatocellular carcinoma (aHCC). Immune checkpoint inhibitors including nivolumab and pembrolizumab have shown survival benefit. More recently, atezolizumab in combination with bevacizumab resulted in improved overall survival and progression-free survival, compared with sorafenib in patients with aHCC in the first-line setting. The combination of nivolumab with ipilimumab as an alternative in the treatment of patients treated with sorafenib has inspired various combination studies of immune checkpoint inhibitors. Currently, ongoing studies of systemic therapy consist of various immune-based combination therapies. Finally, there is no established adjuvant and neoadjuvant therapy although a few early phase studies show promising results. In this chapter, we summarize current approaches of systemic treatment in patients with liver cancer.

Fibrolamellar Hepatocellular Carcinoma: A Population-Based Observational Study

BACKGROUND

In the USA, fibrolamellar hepatocellular carcinoma (FLC) accounts for 1-2% of all cases of hepatocellular carcinoma. FLC remains poorly understood.

AIM

We aim to investigate the incidence, demographics, tumor characteristics, treatment, and prognosis of patients with FLC.

METHODS

Data on FLC between 2000 and 2016 were extracted from the SEER database and analyzed.

RESULTS

A total of 300 patients with FLC were identified where 126 were male. Median age at diagnosis was 27 ± 22 years. The overall age-adjusted incidence of FLC between 2000 and 2016 was 0.02 per 100,000 per year. A bimodal distribution was observed where the highest incidences occurred between 15-19 years and 70-74 years. Most tumors on presentation were moderately differentiated (20.7%), while the most common stage at presentation was stage 1 (21.7%) followed by stages 3 and 4 (20.0% and 20.3%, respectively); 50.3% of these tumors were surgically resected, while 8.0% received radiation and 45.3% received chemotherapy. One- and 5-year cause-specific survival for FLC was 72.0% and 32.9%, respectively, with a median survival of 32.9 months. HCC had a median survival time of 11.7 months. Patients who were not treated with surgical intervention had about 3 times increased risk for death (HR 2.8, 95% CI 1.68-4.72, P = 0.000). Radiation and chemotherapy did not significantly affect outcomes.

CONCLUSION

FLC presents with a bimodal distribution in both early and elderly individuals. Compared to HCC, FLC has a higher recurrence rate but better survival outcome. Surgical intervention is superior to chemotherapy and radiation.

Hotspots of Aberrant Enhancer Activity in Fibrolamellar Carcinoma Reveal Candidate Oncogenic Pathways and Therapeutic Vulnerabilities

Fibrolamellar carcinoma (FLC) is a rare, therapeutically intractable liver cancer that disproportionately affects youth. Although FLC tumors exhibit a distinct gene expression profile, the chromatin regulatory landscape and the genes most critical for tumor cell survival remain unclear. Here, we use chromatin run-on sequencing to discover ∼7,000 enhancers and 141 enhancer hotspots activated in FLC relative to nonmalignant liver. Bioinformatic analyses reveal aberrant ERK/MEK signaling and candidate master transcriptional regulators. We also define the genes most strongly associated with hotspots of FLC enhancer activity, including CA12 and SLC16A14. Treatment of FLC cell models with inhibitors of CA12 or SLC16A14 independently reduce cell viability and/or significantly enhance the effect of the MEK inhibitor cobimetinib. These findings highlight molecular targets for drug development, as well as drug combination approaches.

Spontaneous Rupture of Fibrolamellar Variant Hepatocellular Carcinoma

Fibrolamellar hepatocellular carcinoma (FL-HCC) is a unique variant of hepatocellular carcinoma. The majority of cases present with nonspecific symptoms like vague abdominal pain, weight loss and fatigue. Ruptured FL-HCC occurs rarely and mortality in the acute phase is very high. We report a rare case of a ruptured FL-HCC successfully managed with transarterial embolization for hemostasis. A 37-year-old male previously in good health presented with a severe, sharp epigastric pain that started 1 h prior to the presentation. He denied trauma, fever, nausea, vomiting, or diarrhea. Tenderness in the epigastrium was noted, with no palpable masses, guarding or rigidity. His blood pressure and pulse were 159/105 mm Hg and 105 beats/min. Platelets and coagulation parameters were within normal limits; transaminases were elevated. Abdominal computed tomography (CT) scan with contrast revealed an 8 cm lobulated mass with central hypodensity in the left hepatic lobe with perilesional blood and free pelvic fluid, indicating tumor rupture. CT angiography showed tumor neovascularization from a branch of the left hepatic artery which was embolized using transarterial gelfoam. Liver magnetic resonance imaging (MRI) and biopsy were consistent with fibrolamellar variant hepatocellular carcinoma. After 4 days, as the symptoms resolved, and the lab results were stable, patient was discharged and underwent a left hepatectomy 3 weeks later. FL-HCC occurs commonly in the left lobe of a young and non-cirrhotic liver. Typically, cross sectional imaging reveals a lobulated mass with well-defined margins, areas of hypervascularity and a central calcified scar. Histologic appearance is characterized by eosinophilic polygonal shaped cells separated by lamellar fibrosis. Surgical resection is the treatment of choice with better outcome when compared to conventional HCC. Disease recurrence after complete surgical resection is however high in the first 5 years. Tumors > 5 cm in size are at high risk for rupture with high mortality and recurrence rates secondary to significant spillage of tumor. While an emergency hepatectomy is preferred in unstable patients, those that are hemodynamically stable can undergo radiologic transarterial embolization for hemostasis followed by staged hepatectomy.

Fibrolamellar Hepatocellular Carcinoma and Noncirrhotic Hyperammonemic Encephalopathy

Fibrolamellar hepatocarcinoma is an infrequent liver tumor, currently considered to be a variant different from hepatocarcinoma. The differences lie in genomic alterations, a greater prevalence of fibrolamellar hepatocarcinoma in young patients, and its lack of association with underlying liver disease. The clinical presentation is unspecific, with symptoms ranging from abdominal pain, malaise, and weight loss to atypical manifestation which include hyperammonemic encephalopathy. We present the case of a 33-year-old woman with no prior medical history who presented with a coma and a diagnosis of inoperable fibrolamellar hepatocarcinoma requiring a cadaver donor transplant. While she was on the waiting list, she received hemofiltration and ammonium benzoate treatment, with progressive improvement in her state of consciousness.

Fibrolamellar Hepatocellular Carcinoma: Treatment with Yttrium-90 and Subsequent Surgical Resection

We describe a 52-year-old female patient who presented with a 9.5-cm fibrolamellar hepatocellular carcinoma (FL-HCC). The patient was initially unsuitable for surgical resection and therefore underwent transarterial chemoembolization followed by selective internal radiation therapy (SIRT) with Yttrium-90 to downsize the tumour. Following SIRT, the tumour decreased in volume from 350 to 20 cm³ allowing curative (R0) resection with an extended left hepatectomy and reconstruction of IVC. This is the first reported case of FL-HCC treated with SIRT in which, due to the good SIRT response, the patient was downsized to allow curative resection.

Utility of Cytokeratin7 Immunocytochemistry in the Cytopathological Diagnosis of Fibrolamellar Hepatocellular Carcinoma

Objective

To distinguish fibrolamellar hepatocellular carcinoma (FL-HCC) variant from the conventional hepatocellular carcinoma (HCC) by cytology, immunocytochemistry, and morphometry.

Study Design

Retrospective detailed cytomorphological, immunocytochemical, and morphometric analysis was performed in 6 cases of FL-HCC reported on fine needle aspiration. Cell block immunocytochemistry (CB-ICC) for CK7 and CD68 was performed in four cases. Morphometry was carried out with Cell A software. Area of the cell, nucleus and nucleolus was measured in 50 nuclei per case in 6 cases each of FL-HCC and HCC.

Results

The mean age of patients with FL-HCC was 19 years and all had normal serum alpha-fetoprotein levels. Fine needle aspiration smears showed large polygonal cells with abundant cytoplasm, vesicular nucleus and prominent nucleolus, associated with variably cellular fibrous stromal fragments. Intranuclear inclusions, cytoplasmic eosinophilic inclusions, and bile were also noted. FL-HCC showed strong membrano-cytoplasmic CK7 positivity and cytoplasmic granular and canalicular positivity for CD68. In contrast, HCC showed weak focal positivity for CK7 and only canalicular CD68 positivity. Morphometry revealed that FL-HCC cells were 2.19 times the size of HCC.

Conclusion

CK7 immunocytochemistry on cell blocks is useful for confirming and distinguishing it from HCC.

Non coding RNA analysis in fibrolamellar hepatocellular carcinoma

Fibrolamellar hepatocellular carcinoma (FLC) is a rare primary liver cancer found in adolescents and young adults without underlying liver disease. A deletion of ~400 kD has been found in one copy of chromosome 19 in the tumor tissue of all patients tested. This produces a fusion of the genes DNAJB1 and PRKACA which, in turn, produces a chimeric transcript and protein. Transcriptomic analysis of the tumor has shown upregulation of various oncologically relevant pathways, including EGF/ErbB, Aurora Kinase A, pak21 and wnt. To explore other factors that may contribute to oncogenesis, we examined the microRNA (miRNA) and long non-coding RNA (lncRNA) expression in FLC. The non-coding RNA expression profile in tumor tissue samples is distinctly different from the adjacent normal liver and from other liver tumors. Furthermore, miRZip knock down or over expression of certain miRNAs led to changes in the levels of coding genes that recapitulated changes observed in FLC, suggesting mechanistically that the changes in the cellular levels of miRNA are not merely correlative. Thus, in addition to serving as diagnostic tools for FLC, non-coding RNAs may serve as therapeutic targets.

Prognosis of Fibrolamellar Carcinoma Compared to Non-cirrhotic Conventional Hepatocellular Carcinoma

BACKGROUND

Fibrolamellar carcinoma (FLC) and conventional hepatocellular carcinoma (HCC) share the same American Joint Committee on Cancer (AJCC) staging. The worse survival with HCC is attributed to the underlying cirrhosis.The aim of this study was to compare stage-matched prognosis after resection of FLC and non-cirrhotic HCC.

METHODS

Outcomes after resection of 65 consecutive patients with FLC and 158 non-cirrhotic patients with HCC were compared. Patients were staged according to the 7th edition AJCC staging.

RESULTS

The AJCC stage distributions for FLC and HCC demonstrated a predominance of stage IV disease in FLC and stage I in HCC (FLC stage I-23 %, II-15 %, III-15 %, IV-46 % vs. HCC stage I-42 %, II-32 %, III-20 %, IV-6 %, p < 0.001). Among stage IV FLC patients, 81 % had isolated nodal metastases, which did not affect overall survival (OS) or recurrence-free survival (RFS). In FLC, OS was significantly affected by the number of tumors and vascular invasion (p < 0.05). Recurrent disease developed in 56 (86 %) FLC patients and was treated with repeat surgical resection in 25 (45 %) patients. Vascular invasion was associated with recurrent FLC, with 3-year RFS rates of 9 % and 35 %, with and without vascular invasion (p = 0.034). With respect to RFS, the AJCC staging did not stratify FLC patients, compared to non-cirrhotic HCC.

CONCLUSIONS

When compared to non-cirrhotic HCC, patients with FLC are not adequately stratified by AJCC staging with respect to RFS. Our results support classifying lymph node metastases in FLC as regional disease, rather than systemic disease. Important prognostic factors in FLC are the number of tumors and vascular invasion.

Fibrolamellar Hepatocellular Carcinoma: Mechanistic Distinction From Adult Hepatocellular Carcinoma

Fibrolamellar hepatocellular carcinoma (FL-HCC) has historically been classified as a rare subtype of HCC. However, unlike "classic" HCC, it occurs in children and young adults without underlying liver disease. The recent discovery of a deletion mutation in all FL-HCCs represented a major advancement in understanding the pathogenesis of this disease. This deletion results in the fusion of the genes encoding a heat shock protein (DNAJB1) and the catalytic subunit of protein kinase A (PKA, PRKACA), and overexpression of PRKACA and enhanced cAMP-dependent PKA activity. This review summarizes recent advancements in FL-HCC pathogenesis and characteristics of the HSP40-PKA C protein.

Contemporary management of fibrolamellar hepatocellular carcinoma: diagnosis, treatment, outcome, prognostic factors, and recent developments

Fibrolamellar hepatocellular carcinoma (FL-HCC) is a malignant liver tumor which is thought to be a variant of conventional hepatocellular carcinoma (HCC). It accounts for a small proportion of HCC cases and occurs in a distinctly different group of patients which are young and usually not in the setting of chronic liver disease. The diagnosis of FL-HCC requires the integration of clinical information, imaging studies, and histology. In terms of the treatment options, the only potentially curative treatment option for patients who have resectable disease is surgery either liver resection (LR) or liver transplantation (LT). When performed in a context of aggressive therapy, long-term outcomes after surgery, particularly liver resection for FL-HCC, were favorable. The clinical outcome of patients with unresectable disease is suboptimal with median survival of less than 12 months. The aim of this review is to update the available evidence on diagnosis, treatment options, outcome predictors, and recent developments of patients with this rare disease and to provide a summarized overview of the available literature.

Laboratory assessment of vitamin B12 status

The detection and correction of vitamin B₁₂ (B₁₂) deficiency prevents megaloblastic anaemia and potentially irreversible neuropathy and neuropsychiatric changes. B₁₂ status is commonly estimated using the abundance of the vitamin in serum, with ∼148 pmol/L (200 ng/L) typically set as the threshold for diagnosing deficiency. Serum B₁₂ assays measure the sum of haptocorrin-bound and transcobalamin-bound (known as holotranscobalamin) B₁₂ It is only holotranscobalamin that is taken up by cells to meet metabolic demand. Although receiver operator characteristic curves show holotranscobalamin measurement to be a moderately more reliable marker of B₁₂ status than serum B₁₂, both assays have an indeterminate range. Biochemical evidence of metabolic abnormalities consistent with B₁₂ insufficiency is frequently detected despite an apparently sufficient abundance of the vitamin. Laboratory B₁₂ status markers that reflect cellular utilisation rather than abundance are available. Two forms of B₁₂ act as coenzymes for two different reactions. Methionine synthase requires methylcobalamin for the remethylation of methionine from homocysteine. A homocysteine concentration >20 µmol/L may suggest B₁₂ deficiency in folate-replete patients. In the second B₁₂-dependent reaction, methylmalonyl-CoA mutase uses adenosylcobalamin to convert methylmalonyl-CoA to succinyl-CoA. In B₁₂ deficiency excess methylmalonyl-CoA is hydrolysed to methylmalonic acid. A serum concentration >280 nmol/L may suggest suboptimal status in young patients with normal renal function. No single laboratory marker is suitable for the assessment of B₁₂ status in all patients. Sequential assay selection algorithms or the combination of multiple markers into a single diagnostic indicator are both approaches that can be used to mitigate inherent limitations of each marker when used independently.

Magnetic resonance imaging of primary pediatric liver tumors

Although primary hepatic neoplasms are less common than other intra-abdominal tumors in children, these neoplasms are a significant source of morbidity and mortality in the pediatric population. MRI is increasingly relied upon in the diagnostic evaluation of these lesions, both before and after treatment, and familiarity with the MRI findings associated with these neoplasms is a must for pediatric radiologists. Advances in MRI technology, particularly the advent of hepatocyte-specific gadolinium-based MRI contrast agents, have allowed for accurate characterization of several types of hepatic neoplasms on the basis of imaging appearance. In this review, we provide an overview of the approach to imaging hepatic neoplasms in children using MRI, including a sample imaging protocol. We also discuss the relevant clinical features and MRI findings of the most clinically relevant entities, including their appearance on post-contrast imaging using hepatocyte-specific gadolinium-based MRI contrast agents.

Hepatocellular Carcinoma: Histologic Subtypes

This review discusses the various histologic subtypes of hepatocellular carcinoma (HCC), focusing on their clinical features, pathologic features, immunohistochemical profiles, differential diagnosis, prognosis, and clinical relevance of diagnosis. The WHO recognized variants of scirrhous HCC, fibrolamellar carcinoma, combined HCC-cholangiocarcinoma (HCC-CC), sarcomatoid HCC, undifferentiated carcinoma, and lymphoepithelioma-like HCC are discussed in detail. Other subtypes including clear cell HCC, diffuse cirrhosis-like HCC, steatohepatitic HCC, transitional liver cell tumor, and CAP carcinoma are also reviewed.

Hepatocellular Carcinoma, Fibrolamellar Variant: Diagnostic Pathologic Criteria and Molecular Pathology Update. A Primer

Fibrolamellar hepatocellular carcinoma (FL-HCC) is generally a fairly rare event in routine pathology practice. This variant of hepatocellular carcinoma (HCC) is peculiarly intriguing and,in addition, poorly understood. Young people or children are often the target individuals with this type of cancer. Previously, I highlighted some pathology aspects of FL-HCC, but in this review, the distinctive clinico-pathologic features of FL-HCC and the diagnostic pathologic criteria of FL-HCC are fractionally reviewed and expanded upon. Further, molecular genetics update data with reference to this specific tumor are particularly highlighted as a primer for general pathologists and pediatric histopathologists. FL-HCC may present with metastases, and regional lymph nodes may be sites of metastatic spread. However, peritoneal and pulmonary metastatic foci have also been reported. To the best of our knowledge, FL-HCC was initially considered having an indolent course, but survival outcomes have recently been updated reconsidering the prognosis of this tumor. Patients seem to respond well to surgical resection, but recurrences are common. Thus, alternative therapies, such as chemotherapy and radiation, are ongoing. Overall, it seems that this aspect has not been well-studied for this variant of HCC and should be considered as target for future clinical trials. Remarkably, FL-HCC data seem to point to a liver neoplasm of uncertain origin and unveiled outcome. A functional chimeric transcript incorporating DNAJB1 and PRKACA was recently added to FL-HCC. This sensational result may give remarkable insights into the understanding of this rare disease and potentially provide the basis for its specific diagnostic marker. Detection of DNAJB1-PRKACA seems to be, indeed, a very sensitive and specific finding in supporting the diagnosis of FL-HCC. In a quite diffuse opinion, prognosis of this tumor should be reconsidered following the potentially mandatory application of new molecular biological tools.

Fibrolamellar hepatocellular carcinoma: current clinical perspectives

Fibrolamellar carcinoma (FLC) is a variant of hepatocellular carcinoma (HCC), which comprises ∼1%–9% of all HCCs. Although FLC is a variant of HCC, it is distinct from HCC in that it most often affects younger patients (10–35 years of age) with no underlying liver disease. FLC often presents with vague abdominal pain, nausea, abdominal fullness, malaise, and weight loss. Surgery is the current mainstay of treatment for FLC and remains the only potentially curative option. While FLCs are considered less responsive to chemotherapy than their classic HCC counterparts, there have been suggestions that multimodality treatments may be effective, especially in advanced cases. Further research is necessary to determine effective systemic therapies as an adjunct to surgery for FLC.

Metastatic Fibrolamellar Hepatocellular Carcinoma to the Pancreas

Fibrolamellar hepatocellular carcinoma (FL-HCC) is a rare variant of hepatocellular carcinoma, usually presenting in the younger population (<40 years) without underlying liver disease. Although it has a better prognosis than hepatocellular carcinoma, it has a high rate of recurrence months to years after primary resection. While sites of recurrence usually involve the liver, regional lymph nodes, peritoneum, and lung, metastasis to the pancreas is extremely rare, with only 2 other cases reported in the literature. We present the case of a 46-year-old patient with metastatic FL-HCC to the pancreas 30 years after diagnosis and 26 years since his last resected liver recurrence.

A case of fibrolamellar cancer with a palliative response and minor radiographic regression with erlotinib and bevacizumab combination therapy

Fibrolamellar cancer (FLC) is a rare primary hepatic malignancy with no established standard systemic treatments. Case reports and subgroup analyses from larger liver cancer studies suggest possible activity for fluoropyrimidines, platinum agents, and interferon-α. However, randomized studies are lacking, and the merits of any particular regimen in FLC are still largely unsubstantiated. We report the outcome of a case of metastatic FLC with previous progressive disease on 5-FU plus interferon-α and FOLFOX regimens that was treated with bevacizumab and erlotinib. The patient derived a prompt palliative response with complete resolution of cancer-related pain 2 weeks after initiation of erlotinib. Computed tomography after 2 months of treatment showed disease regression in distant lymphadenopathy. Molecular testing failed to confirm any evidence of epidermal growth factor receptor (EGFR) mutation, whereas immunohistochemistry showed 2 to 3+ staining for EGFR expression. To our knowledge, this is the first case report of a clinical benefit for FLC in association with erlotinib and bevacizumab treatment. FLC overexpresses EGFR in comparison to hepatocellular cancer, suggesting that EGFR targeting may be an interesting therapeutic approach in this rare malignancy.

Liver transplantation for malignancies

Liver transplantation (LT) has become an acceptable and effective treatment for selected patients with hepatocellular carcinoma with excellent outcomes. More recently, LT has been tried in different primary and secondary malignancies of the liver. The outcomes of LT for very selected group of patients with hilar cholangiocarcinoma (CCA) have been promising. Excellent results have been reported in LT for patients with unresectable hepatic epithelioid hemangioendothelioma (HEHE). In contrast to excellent results after LT for HEHE, results of LT for angiosarcoma have been disappointing with no long-term survivors. Hepatoblastoma (HB) is the most common primary liver cancer in pediatric age group. Long-term outcomes after LT in patients with unresectable tumor and good response to chemotherapy have been promising. Indication for LT for hepatic metastasis from neuroendocrine tumors (NETs) is mainly for patients with unresectable tumors and for palliation of medically uncontrollable symptoms. Posttransplant survival in those patients with low tumor activity index is excellent, despite recurrence of the tumor. More recent limited outcomes data on LT for unresectable hepatic metastases from colorectal cancer have claimed some survival benefit compared to the previous reports. However, due to the high rate of tumor recurrence in a very short time after LT, especially in the era of organ shortage, this indication has not been favored by the transplant community.

Clinical and pathological evaluation of fibrolamellar hepatocellular carcinoma: a single center study of 21 cases

OBJECTIVES

Fibrolamellar hepatocellular carcinoma is a rare primary malignant liver tumor that differs from conventional hepatocellular carcinoma in several aspects. The aim of this study was to describe the clinical, surgical and histopathological features of fibrolamellar hepatocellular carcinoma and to analyze the factors associated with survival.

METHODS

We identified 21 patients with histopathologically diagnosed fibrolamellar hepatocellular carcinoma over a 22-year period. Clinical information was collected from medical records and biopsies, and surgical specimens were reviewed.

RESULTS

The median age at diagnosis was 20 years. Most patients were female (67%) and did not have associated chronic liver disease. Most patients had a single nodule, and the median tumor size was 120 mm. Vascular invasion was present in 31% of patients, and extra-hepatic metastases were present in 53%. Fourteen patients underwent surgery as the first-line therapy, three received chemotherapy, and four received palliative care. Eighteen patients had "pure fibrolamellar hepatocellular carcinoma," whereas three had a distinct area of conventional hepatocellular carcinoma and were classified as having "mixed fibrolamellar hepatocellular carcinoma." The median overall survival was 36 months. The presence of "mixed fibrolamellar hepatocellular carcinoma" and macrovascular invasion were predictors of poor survival. Vascular invasion was associated with an increased risk of recurrence in patients who underwent surgery.

CONCLUSION

Fibrolamellar hepatocellular carcinoma was more common in young female patients without chronic liver disease. Surgery was the first therapeutic option to achieve disease control, even in advanced cases. Vascular invasion was a risk factor for tumor recurrence. The presence of macrovascular invasion and areas of conventional hepatocellular carcinoma were directly related to poor survival.

Hepatocarcinoma fibrolamelar un tumor de adultos jóvenes poco frecuente. Reporte de un caso

El hepatocarcinoma fibrolamelar (CHC-FL) es una rara variante del carcinoma hepatocelular (CHC), se presenta con mayor frecuencia en adultos jóvenes, sin distinción de sexo, se desarrolla en su manera más característica sobre un hígado previamente sano. La manifestación clásica está dada por la triada de masa palpable en hipocondrio derecho, dolor y pérdida de peso. Ante la ausencia de historia de enfermedad hepática previa, es usual que se encuentre como una neoplasia avanzada de gran tamaño, la cual tiene hallazgos característicos en la tomografía o en la RM, que permiten en un alto porcentaje de casos hacer el diagnóstico solo con las imágenes. En este tipo de neoplasias, el mejor tratamiento es la resección quirúrgica, que proporciona una sobrevida a 5 años de 58-82%, pero con unas tasas de recaídas muy elevadas, que puede variar según las series entre 33-100% de los casos. Presentamos el caso de un paciente joven, sin historia de enfermedad hepática, en el que se diagnosticó un CHC-FL mediante el uso de resonancia magnética con medio de contraste órgano-específico y que es tratado con resección quirúrgica radical.

Surgical treatment of fibrolamellar hepatocellular carcinoma: an underestimated malignant tumor?

BACKGROUND

Fibrolamellar hepatocellular carcinoma (FLHCC) is a rare disease with an indolent behavior. Its prognosis is better than that of patients with hepatocellular carcinoma. The authors present their experience with resection of FLHCC.

METHODS

Twenty-one patients with FLHCC were treated at our institution between 1990 and 2012. Of these patients, 14 were subjected to resection of the tumor. Patient demographics, medical history, results of imaging studies and laboratory tests, surgical data, and pathologic findings were evaluated.

RESULTS

The median age of the patients at the diagnosis of the tumor was 20 years and 14 patients were female. None of the patients had tumor-associated chronic liver disease or cirrhosis. The mean tumor size was 12.8 cm (range 6-19) and 18 patients had a single liver nodule. Fourteen patients were subjected to hepatectomy and six of them had lymph node metastases resected. Pathologic evaluation revealed that 5 (35.7%) patients had major vascular invasion. Tumor recurrence was seen in 8 patients (66.7%), during a follow-up. The median survival time for patients who were subjected to resection was 36 months. The 5-year overall survival rate and disease free survival rate were 28.0% and 8.5%, respectively. Univariate analysis showed that vascular invasion was the only variable associated with the disease free survival rate.

CONCLUSIONS

Despite an aggressive treatment, patients with FLHCC presented unexpected low survival rates. It seems that an underestimated malignant behavior is attributed to this disease, and that the forms of adjuvant treatment should be urgently evaluated.

Treatment and prognosis of patients with fibrolamellar hepatocellular carcinoma: a national perspective

BACKGROUND

Surgery remains the only potentially curative option for patients with hepatocellular carcinoma (HCC) and fibrolamellar carcinoma (FLC). We sought to investigate the differences over time in surgically managed FLC compared with conventional HCC using population-based data.

STUDY DESIGN

Using SEER data, we identified 7,225 patients with surgically managed FLC or HCC from 1986 to 2008. We examined differences in clinicopathologic and surgical factors associated with long-term survival.

RESULTS

Of the 7,225 patients, the majority had HCC (n = 7,135; 99%) vs FLC (n = 90; 1%). Patients with FLC were younger (25 years vs 59 years) and more often were women (44% vs 27%) than patients with HCC (both p < 0.001). Regional disease was more common among patients with FLC (42.2%) vs patients with HCC (22.1%) (p < 0.001). More than one-third of patients with FLC (36.9%) were operatively managed with a hemihepatectomy compared with patients with HCC, who were more often managed with a liver transplant (p < 0.001). On univariable analysis, there was a marked difference in overall survival, with patients with FLC surviving a median of 75 months vs 43 months for HCC (hazard ratio [HR]: 0.59; p = 0.001). There was a marked difference in survival when patients were stratified by localized (FLC, 78 months vs HCC, 49 months; p = 0.012) vs regional disease (FLC, 46 months vs HCC, 23 months; p = 0.002.

CONCLUSIONS

Patients with FLC have many clinicopathologic features that are different from those of patients with HCC, including younger age and female sex. Despite a higher likelihood of advanced disease at the time of diagnosis, surgically treated FLC patients had better long-term outcomes than patients with conventional HCC.

Radiotherapy for metastatic fibrolamellar hepatocellular carcinoma

Fibrolamellar hepatocellular carcinoma (FLHCC) is a rare variant of hepatocellular carcinoma (HCC) that commonly affects young individuals without a prior history of liver disease. FLHCC commonly results in a better prognosis than HCC; however, the risk of recurrence and metastatic disease is high. FLHCC is typically treated by primary resection of the tumor with 50-75% cure rates. The use of radiation therapy in FLHCC has not been assessed on its own, and may show some success in a very few reported combination therapy cases. We report on the successful use of radiation therapy in a case of metastatic FLHCC to the lung following primary and secondary resections. Our treatment of the large, metastatic, pulmonary FLHCC tumor with 40 Gy in 10 fractions resulted in an 85.9% tumor volume decrease over six months. This suggests FLHCC may be a radiosensitive tumor and radiotherapy may be valuable in unresectable or metastatic tumors.

Fibrolamellar variant of hepatocellular carcinoma

The fibrolamellar variant of hepatocellular carcinoma is a rare primary liver cancer occurring in adolescents and young adults without chronic liver disease or known risk factors. Histologically, it is defined by lamellar bands of fibrosis surrounding well-differentiated tumor cells. Radiologic imaging typically demonstrates a large, solitary mass with calcifications and a central scar. Lymph node metastases in the porta hepatis are frequently diagnosed upon presentation. More patients with fibrolamellar carcinoma are candidates for surgical resection than those with conventional hepatocellular carcinoma, owing to their young age and absence of cirrhosis. The most important prognostic factor is surgical resection, which results in 5-year overall survival rates ranging between 50 and 76 %. Despite complete surgical resection, relapse rates are high, and novel therapies are needed to prevent and treat recurrent disease.

Fibrolamellar carcinoma: 2012 update

Fibrolamellar carcinomas are a unique type of primary liver cancer. They occur most commonly in children and young adults. Their etiology remains a mystery, as they are not associated with chronic liver disease. Fibrolamellar carcinomas are not indolent tumors, but have an overall better prognosis than typical hepatocellular carcinomas, in part because of the younger age at presentation and the lack of cirrhosis. The most important prognostic feature is whether the tumor is resectable. Histologically, the tumor is made up of large cells that contain abundant mitochondria. The nuclei of the tumor cells have prominent nucleoli. The tumor cells induce the formation of extensive intratumoral fibrosis, which often grows in parallel, or lamellar bands. The tumor cells clearly show hepatocellular features but are also unique in showing both biliary and neuroendocrine differentiation. The uniqueness of fibrolamellar carcinoma extends to their molecular findings. While the genetic abnormalities that lead to fibrolamellar carcinomas are not yet known, studies have shown that they lack mutations in the genes most commonly mutated in typical hepatocellular carcinoma (TP53 and CTNNB1). In this paper, the clinical, pathological, and basic science literature on fibrolamellar carcinoma is comprehensively reviewed. Key areas of needed research are also discussed.

A systematic review: treatment and prognosis of patients with fibrolamellar hepatocellular carcinoma

BACKGROUND

Fibrolamellar hepatocellular carcinoma (FLC) is a rare primary liver tumor presenting earlier in life than nonfibrolamellar hepatocellular carcinoma (NFL-HCC), with distinct epidemiologic and clinical characteristics. Although FLC is believed to have a better prognosis than NFL-HCC, data on treatment and prognosis are scarce. We performed a systematic review to investigate treatment options and clinical outcomes of patients with FLC.

STUDY DESIGN

The study is a systematic review of the literature and pooled analysis of individual patient data.

RESULTS

A total of 35 series were analyzed, reporting on 575 patients (52% female, elevated alpha-fetoprotein in 10%, cirrhosis in 3%, hepatitis B in 2%), most of whom were treated with partial hepatectomy (55%) or orthotopic liver transplantation (23%). Nineteen studies provided data on 206 individual patients with a median age of 21 years and tumor size of 12 cm. Median overall survival (OS) was 39 months; 1-year, 3-year, and 5-year OS rates were 85%, 53%, and 44%, respectively. For patients treated with liver resection, median OS was 18.5 years and 1-year, 3-year, and 5-year OS were 93%, 80%, and 70%, respectively. Based on data from 15 studies, FLC appeared to follow a relatively indolent course compared with NFL-HCC.

CONCLUSIONS

Patients with FLC treated with partial hepatectomy have excellent long-term survival, with 5-year overall survival reaching 70%. Patients fared worse with the use of other therapeutic options including chemotherapy, intra-arterial therapy, and transplantation, although data directly comparing resection vs transplantation were limited.

Pure and mixed fibrolamellar hepatocellular carcinomas differ in natural history and prognosis after complete surgical resection

BACKGROUND

The purpose of the current study was to describe pure and mixed fibrolamellar hepatocellular carcinoma (FL-HCC).

METHODS

Consecutive patients with pure and mixed FL-HCC were identified from a central pathological review using Edmondson's criteria. Clinical, pathological, and epigenetic characteristics of patients who underwent curative surgery were evaluated. Overall and disease-free survival as well as patterns of disease recurrence were examined. Methylation levels of L1 retrotransposon (LINE-1) repetitive elements and Ras association domain family 1A gene (RASSF1) promoter were also assessed using pyrosequencing.

RESULTS

Forty of 53 patients with a median age of 22 years (range, 9 years-;65 years) met the criteria for analysis. Central pathological review found that 30 patients (75%) had pure and 10 patients (25%) had mixed FL-HCC. Pure FL-HCC typically occurred in patients aged < 30 years. These patients often presented with lymph node metastasis at the time of diagnosis and frequently experienced extrahepatic recurrences (n = 16). Conversely, mixed FL-HCC appeared to resemble to classic HCC, occurring in patients aged > 40 years and frequently involving the liver as the primary site of disease recurrence. With a median follow-up of 7.8 years, the median overall survival from the time of diagnosis in all patients was 6.4 years (range, 3.2 years-12 years). Multivariate analysis found that the risk of death was increased in patients with higher American Joint Committee on Cancer disease stages (P = .003) and those with mixed FL-HCC (P = .03). Methylation analysis of LINE-1 repetitive elements and RASSF1 promoter revealed different methylation levels between pure and mixed FL-HCC, suggesting a different epigenetic background.

CONCLUSIONS

Pure and mixed FL-HCC display distinct clinical presentations and epigenetic backgrounds leading to different prognoses and as such may be regarded as separate clinical entities.

Loss of the orphan nuclear receptor SHP is more pronounced in fibrolamellar carcinoma than in typical hepatocellular carcinoma

Hepatocellular carcinoma (HCC) remains a major problem in oncology. The molecular mechanisms which underlie its pathogenesis are poorly understood. Recently the Small Heterodimer Partner (SHP), an orphan nuclear receptor, was suggested to be involved as a tumor suppressor in hepatocellular carcinoma development. To date, there are no such studies regarding fibrolamellar carcinoma, a less common variant of HCC, which usually affects young people and displays distinct morphological features. The aim of our project was to evaluate the SHP levels in typical and fibrolamellar hepatocellular carcinoma with respect to the levels of one of the cell cycle regulators, cyclin D1. We assessed the immunoreactivity levels of SHP and cyclin D1 in 48 typical hepatocellular carcinomas, 9 tumors representing the fibrolamellar variant, 29 non malignant liver tissues and 7 macroregenerative nodules. We detected significantly lower SHP immunoreactivity in hepatocellular carcinoma when compared to non malignant liver tissue. Moreover, we found that SHP immunoreactivity is reduced in fibrolamellar carcinoma when compared to typical hepatocellular carcinoma. We also found that SHP is more commonly lost in HCC which arises in the liver with steatosis. The comparison between the cyclin D1 and SHP expression revealed the negative correlation between these proteins in the high grade HCC. Our results indicate that the impact of loss of SHP protein may be even more pronounced in fibrolamellar carcinoma than in a typical form of HCC. Further investigation of mechanisms through which the loss of SHP function may influence HCC formation may provide important information in order to design more effective HCC therapy.