Treatment of Paraneoplastic Hyperammonemia in Fibrolamellar Hepatocellular Carcinoma With Oral Sodium Phenylbutyrate

Paraneoplastic syndromes in hepatocellular carcinoma: a review

INTRODUCTION

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide, and a significant proportion (20-40%) of patients with HCC develop paraneoplastic syndromes (PNS). Despite this, there is a paucity of clinical evidence regarding PNS in HCC.

AREAS COVERED

A systematic search was performed to identify relevant case studies regarding PNS in HCC. Another search was conducted to identify studies that evaluated the impact of PNS on survival outcomes in HCC. Since there are currently no international guidelines for PNS in HCC, this review aims to provide comprehensive summaries and recommendations of PNS in HCC, including the pathophysiology, clinical features, diagnostic approach, and management, so that clinicians remain guided in caring for HCC patients with PNS. In general, PNS are associated with poorer survival outcomes and negative prognostic markers of HCC.

EXPERT OPINION

The presence of PNS has a significant influence on survival rates and clinical outcomes of patients with HCC. They contribute to significant morbidity, influencing patients' quality of life and fitness for curative and palliative therapies. Therefore, it is paramount for PNS to be integrated into routine investigations after diagnosing HCC to guide further management and prognostication of the disease.

Clinical features and surgical outcomes of fibrolamellar hepatocellular carcinoma: retrospective analysis of a single-center experience

Background

Clinicopathological features and surgical outcomes of patients with fibrolamellar hepatocellular carcinoma (FL-HCC) are underreported. The aim of this study is to describe clinical characteristics and surgical outcomes for patients with this rare tumor to raise awareness among clinicians and surgeons.

Methods

Retrospective review of records of a tertiary referral center and specialized liver unit was performed. Out of 3623 patients who underwent liver resection, 366 patients received surgical treatment for HCC; of them, eight (2.2%) had FL-HCC and were resected between October 2001 and December 2018.

Results

Eight patients (3 males and 5 females) with FL-HCC (median age 26 years) underwent primary surgical treatment. All patients presented with unspecific symptoms or were diagnosed as incidental finding. No patient had cirrhosis or other underlying liver diseases. Coincidentally, three patients (37.5%) had a thromboembolic event prior to admission. The majority of patients had BCLC stage C and UICC stage IIIB/IVA; four patients (50%) presented with lymph node metastases. The median follow-up period was 33.5 months. The 1-year survival was 71.4%, and 3-year survival was 57.1%. Median survival was at 36.4 months. Five patients (62.5%) developed recurrent disease after a median disease-free survival of 9 months. Two patients (25.0%) received re-resection.

Conclusion

FL-HCC is a rare differential diagnosis of liver masses in young patients. Since the prognosis is limited, patients with incidental liver tumors or lesions with suspicious features in an otherwise healthy liver should be presented at a specialized hepatobiliary unit. Thromboembolism might be an early paraneoplastic symptom and needs to be elucidated further in the context of FL-HCC.

Hyperammonemic encephalopathy in a patient with fibrolamellar hepatocellular carcinoma: case report and literature review

Fibrolamellar hepatocellular carcinoma (fHCC) is a rare primary liver cancer that affects young adults with no prior liver disease. fHCC-associated hyperammonemic encephalopathy (HAE) is an uncommon and life-threatening complication. Hyperammonemia has been reported in both typical and fHCC as a result of intrahepatic shunting, side effect from immunotherapy or chemotherapy, or as a paraneoplastic phenomenon. We present a case of a 32-year-old woman with recurrent metastatic fHCC who developed HAE in the setting of steroid administration. Her hyperammonemia was exacerbated by steroid-induced protein catabolism. She was treated with ammonia scavenging medications, a low protein diet, and was placed on chronic ammonia scavenger therapy while undergoing chemotherapy. In this case report, we discuss the proposed mechanisms of HAE, and we review the literature regarding clinical presentation and treatment.

Acquired ornithine transcarbamylase deficiency in pediatric and adolescent patients with fibrolamellar hepatocellular carcinoma

Ornithine transcarbamylase deficiency (OTCD) disrupts the metabolic pathway responsible for converting nitrogenous waste to urea, allowing for excretion. When impaired, ammonia levels accumulate in the blood resulting in severe, sometimes life-threatening toxicities. Abnormalities of the urea cycle are often inherited, though there are some rarer acquired forms. We describe two cases of acquired OTCD in pediatric patients with fibrolamellar hepatocellular carcinoma (FL-HCC). We detail its presentation and management, explore potential underlying pathophysiology, and propose a practice change to optimize care of FL-HCC patients.

A Proposed Physiopathological Pathway to Hyperammonemic Encephalopathy in a Non-Cirrhotic Patient with Fibrolamellar Hepatocellular Carcinoma without Ornithine Transcarbamylase (OTC) Mutation

Patient: Male, 31

Final Diagnosis: Fibrolamellar hepatocellular carcinoma

Symptoms: Encephalopathy

Medication:—

Clinical Procedure: —

Specialty: Gastroenterology and Hepatology

Hyperammonemic Encephalopathy Associated With Fibrolamellar Hepatocellular Carcinoma: Case Report, Literature Review, and Proposed Treatment Algorithm

We report a case of a 31-year-old man with metastatic fibrolamellar hepatocellular carcinoma (FLHCC) treated with gemcitabine and oxaliplatin complicated by hyperammonemic encephalopathy biochemically consistent with acquired ornithine transcarbamylase deficiency. Awareness of FLHCC-associated hyperammonemic encephalopathy and a pathophysiology-based management approach can optimize patient outcome and prevent serious complications. A discussion of the management, literature review, and proposed treatment algorithm of this rare metabolic complication are presented.

IMPLICATIONS FOR PRACTICE

Pathophysiology-guided management of cancer-associated hyperammonemic encephalopathy can improve patient outcome and prevent life-threatening complications. Community and academic oncologists should be aware of this serious metabolic complication of cancer and be familiar with its management.