Hypercalcemia and parathyroid hormone-related protein in hepatocellular carcinoma

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.

Hepatocellular carcinoma in patients with renal dysfunction: Pathophysiology, prognosis, and treatment challenges

The population of patients with hepatocellular carcinoma (HCC) overlaps to a high degree with those for chronic kidney disease (CKD) and end-stage renal disease (ESRD). The degrees of renal dysfunction vary, from the various stages of CKD to dialysis-dependent ESRD, which often affects the prognosis and treatment choice of patients with HCC. In addition, renal dysfunction makes treatment more difficult and may negatively affect treatment outcomes. This study summarized the possible causes of the high comorbidity of HCC and renal dysfunction. The possible mechanisms of CKD causing HCC involve uremia itself, long-term dialysis status, immunosuppressive agents for postrenal transplant status, and miscellaneous factors such as hormone alterations and dysbiosis. The possible mechanisms of HCC affecting renal function include direct tumor invasion and hepatorenal syndrome. Finally, we categorized the risk factors that could lead to both HCC and CKD into four categories: Environmental toxins, viral hepatitis, metabolic syndrome, and vasoactive factors. Both CKD and ESRD have been reported to negatively affect HCC prognosis, but more research is warranted to confirm this. Furthermore, ESRD status itself ought not to prevent patients receiving aggressive treatments. This study then adopted the well-known Barcelona Clinic Liver Cancer guidelines as a framework to discuss the indicators for each stage of HCC treatment, treatment-related adverse renal effects, and concerns that are specific to patients with pre-existing renal dysfunction when undergoing aggressive treatments against CKD and ESRD. Such aggressive treatments include liver resection, simultaneous liver kidney transplantation, radiofrequency ablation, and transarterial chemoembolization. Finally, focusing on patients unable to receive active treatment, this study compiled information on the latest systemic pharmacological therapies, including targeted and immunotherapeutic drugs. Based on available clinical studies and Food and Drug Administration labels, this study details the drug indications, side effects, and dose adjustments for patients with renal dysfunction. It also provides a comprehensive review of information on HCC patients with renal dysfunction from disease onset to treatment.

Guide for diagnosis and treatment of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is ranked as the 5^th common type of cancer worldwide and is considered as the 3^rd common reason for cancer-related deaths. HCC often occurs on top of a cirrhotic liver. The prognosis is determined by several factors; tumour extension, alpha-fetoprotein (AFP) concentration, histologic subtype of the tumour, degree of liver dysfunction, and the patient’s performance status. HCC prognosis is strongly correlated with diagnostic delay. To date, no ideal screening modality has been developed. Analysis of recent studies showed that AFP assessment lacks adequate sensitivity and specificity for effective surveillance and diagnosis. Many tumour markers have been tested in clinical trials without progressing to routine use in clinical practice. Thus, surveillance is still based on ultrasound (US) examination every 6 mo. Imaging studies for diagnosis of HCC can fall into one of two main categories: routine non-invasive studies such as US, computed tomography (CT), and magnetic resonance imaging, and more specialized invasive techniques including CT during hepatic arteriography and CT arterial portography in addition to the conventional hepatic angiography. This article provides an overview and spotlight on the different diagnostic modalities and treatment options of HCC.

TGF-β Induces Degradation of PTHrP Through Ubiquitin-Proteasome System in Hepatocellular Carcinoma

Both transforming growth factor-β (TGF-β) and parathyroid hormone-related protein (PTHrP) regulate important cellular processes, such as apoptosis in the development of hepatocellular carcinoma. However, the mechanisms of regulation of PTHrP by TGF-β are largely unknown. We hypothesized that TGF-β regulates the expression of PTHrP protein through a post-translational mechanism. Using hepatocellular carcinoma cell lines as the in vitro model, we investigated the effects of TGF-β on protein expression and post-translational processing of PTHrP. We found that TGF-β treatment led to protein degradation of PTHrP through the ubiquitin-proteasome-dependent pathway. We also provided evidence to show that Smurf2 was the E3 ligase responsible for the ubiquitination of PTHrP. Furthermore, using immunohistochemistry on human hepatocellular carcinoma specimens and a tissue array, we found that the expression of PTHrP was predominantly in the cancer cells, whereas the expression of TGF-β was present in non-neoplastic liver tissue adjacent to hepatocellular carcinoma. Our findings reveal a novel mechanism whereby TGF-β may regulate PTHrP in hepatocellular carcinogenesis and lack of TGF-β in hepatocellular carcinoma may promote cancer progression. Promotion of PTHrP degradation provides a novel target of therapeutic intervention to sensitize hepatocellular carcinoma cells to cytostatic and/or pro-apoptotic signals.

Prognostic Role and Significance of Paraneoplastic Syndromes in Hepatocellular Carcinoma

Patients with hepatocellular carcinoma (HCC) may develop paraneoplastic syndromes in the clinical course. These syndromes include hypercholesterolemia, hypoglycemia, hypercalcemia, and erythrocytosis, among others. This study was designed to assess the role of prognostic influence of paraneoplastic syndromes in patients with HCC. In a cohort of 175 patients with HCC patients, we compared the clinical features of patients with HCC with or without paraneoplastic syndromes. In addition, survival rates of patients with individual paraneoplastic syndromes and those without were also evaluated. Moreover, factors independently predicting prognosis among patients with HCC with or without paraneoplastic syndromes were analyzed. Among 175 patients with HCC, 54 patients presented paraneoplastic syndromes, and the prevalence was 30.9 per cent. There was no difference of clinical characteristics between patients with HCC with and without paraneoplastic syndromes on diagnosis. However, the patients with paraneoplastic syndromes had a significantly less survival rate comparing with those without during a 5-year follow-up. Cox regression analysis demonstrated that high Child-Pugh grade, large tumor size, portal vein tumor thrombosis, and distant metastasis were all independent unfavorable prognostic factors for survival of patients with HCC. Paraneoplastic syndromes as independent risk factors play a significant role in the progress of HCC and lead to poor prognosis in patients with HCC.

Reduced expression of low-density lipoprotein receptor in hepatocellular carcinoma with paraneoplastic hypercholesterolemia

BACKGROUND AND AIM

Hepatocellular carcinoma (HCC) is frequently associated with paraneoplastic hypercholesterolemia. In familial hypercholesterolemia, genetic mutation of the low-density lipoprotein (LDL) receptor gene has been recognized as being a pathogenesis of the disease. We investigate the expression of a LDL receptor protein and gene abnormalities of a LDL receptor in HCC cells in cases with paraneoplastic hypercholesterolemia.

METHODS

Eleven patients with HCC associated with paraneoplastic hypercholesterolemia and seven patients with HCC who did not have hypercholesterolemia were studied. Paraffin-embedded tissues were obtained at operative resection, autopsy, or biopsy. Immunohistochemistry was performed using a monoclonal antibody against human LDL receptors. Confocal laser-scanning microscopy was used to observe the FITC-labeled LDL receptor. DNA samples were extracted from paraffin-embedded tissues. Since a LDL receptor gene is located on chromosome 19p13.2, a microsatellite marker, D19S413, was used to analyze the chromosomes.

RESULTS

Immunoreactive LDL receptors were observed all over the surface of non-tumorous hepatocytes. However, expression of the LDL receptor was significantly decreased in all HCC cells derived from the 11 patients with hypercholesterolemia. In contrast, the expression was retained in the HCC cells of all patients without hypercholesterolemia. In two patients with hypercholesterolemia, DNA analysis revealed a loss of heterozygosity on chromosome 19p13.2.

CONCLUSION

We demonstrated reduced expression of the LDL receptor in HCC cases with paraneoplastic hypercholesterolemia. LDL receptor genes with genomic disorders may cause decreased expression of the LDL receptor protein, leading to feed-back failure of the cholesterol regulation system, as seen in familial hypercholesterolemia. This is the first report considering the mechanism behind the development of paraneoplastic hypercholesterolemia in HCC.

Thrombocytosis: A paraneoplastic syndrome in patients with hepatocellular carcinoma

AIM: Hepatocellular carcinoma (HCC) patients manifest a variety of paraneoplastic syndromes. Thrombocytosis was reported in children with hepatoblastoma. The aims of this study were to evaluate the prevalence and clinical significance of thrombocytosis in HCC patients and its relationships with serum thrombopoietin (TPO).

METHODS: We retrospectively reviewed clinical, biochemical and image data of 1154 HCC patients. In addition, we measured platelet count and serum TPO in HCC patients with and without thrombocytosis, in patients with cirrhosis, chronic hepatitis and healthy subjects in a cross-sectional study.

RESULTS: Thirty-one (2.7%) of 1154 HCC patients had thrombocytosis (platelet count ≥ 400 K/mm³). HCC patients with thrombocytosis were significantly younger, had a higher serum α-fetoprotein, higher rate of main portal vein thrombosis, larger tumor volume, shorter survival, and were less likely to receive therapy than HCC patients without thrombocytosis. Multivariate logistic regression analyses showed that tumor volumes ≥ 30% and serum α-fetoprotein ≥ 140000 ng/mL could significantly predict thrombocytosis. HCC patients with thrombocytosis had a significantly higher mean serum TPO than those without, as well as patients with cirrhosis, chronic hepatitis and healthy subjects. Platelet count and serum TPO dropped significantly after tumor resection in HCC patients with thrombocytosis and re-elevated after tumor recurred. Furthermore, the expression of TPO mRNA was found to be more in tumor tissues than in non-tumor tissues of liver in an HCC patient with thrombocytosis.

CONCLUSION: Thrombocytosis is a paraneoplastic syndrome of HCC patients due to the overproduction of TPO by HCC. It is frequently associated with a large tumor volume and high serum α-fetoprotein.

Prevalence of Metastases in Hepatocellular Carcinoma: Risk Factors and Impact on Survival

The purpose of this study was to determine the prevalence and risk factors of metastases in hepatocellular carcinoma (HCC) patients and analyze the effects of different locations of metastases on survival. Retrospective analysis was performed on 347 HCC patients who received a metastatic workup including bone scan and computed tomography scans of chest, abdomen, and pelvis. Clinical and tumor characteristics were evaluated as risk factors for metastasis by univariate and multivariate methods. Survival was analyzed by Kaplan-Meier and Cox regression methods. One hundred forty-five patients had metastases: 71 had thoracic, 57 had abdominal, and 34 had bone metastases. Significant differences were noted with weight loss, hepatitis C, tumor grade, tumor multifocality, size, and alkaline phosphatase levels between the metastases group and the nonmetastases group by univariate analysis. Poor differentiation, multilobar spread, and size (≥5 cm) were strongest predictors of metastatic disease by logistic regression. Patients with thoracic metastases had significantly poorer survival. HCC metastasis is prevalent on initial presentation. Evaluation for liver transplantation or curative resection requires a full metastatic workup. Poor differentiation, larger tumors, and those with multilobar spread have increased risk for metastasis. Patients with thoracic spread have poor prognosis as compared to other locations of metastasis.

Hypercalcemic complication in patients with oral squamous cell carcinoma

Hypercalcemia is one of the metabolic complications associated with cancer. To assess the frequency of hypercalcemia in patients with squamous cell carcinoma (SCC), 242 patients who were evaluated as having SCC in the oral cavity between July 1995 and June 2001 were investigated. All patients were periodically monitored for their serum level of calcium (Ca). Hypercalcemia was defined as a serum Ca concentration higher than 11 mg/dl. By this definition, hypercalcemia was detected in 12 of the 242 patients (5.0%). All 12 patients were at an advanced stage of oral SCC. In these 12 patients, the serum level of parathyroid hormone-related protein (PTH-rP) was also significantly elevated. Therefore, we diagnosed these diseases as humoral hypercalcemia of malignancy (HHM). Moreover, we studied the efficacy of anti-hypercalcemic therapy on the quality of life (QOL). The European Organization for Research and Treatment of Cancer (EORTC) QLQ-C30 was used for estimation of QOL. The patients with HHM who were administrated drugs such as bisphosphonate and calcitonin showed a reduction in their Ca and PTH-rP levels, and the six of ten EORTC QLQ-C30 subscales (emotional functioning, cognitive functioning, fatigue, dyspnoea, nausea/vomiting and appetite loss) were also improved after the anti-hypercalcemic therapy. However, these suppressive effects were temporary. The median survival time after the diagnosis of HHM was only 54.9+/-18.3 days (range 27-86 days). Therefore, HHM in SCC appears to be an ominous prognostic sign. Although anti-hypercalcemic therapy has a palliative role, the patients may be in less discomfort during the terminal stage of their illness.

Paraneoplastic syndromes in patients with hepatocellular carcinoma in Taiwan

BACKGROUND

Hepatocellular carcinoma (HCC) is the most common malignancy in Taiwan. Some patients may manifest paraneoplastic syndromes during the clinical course of the disease. In this study, the authors evaluated the clinical significance of these paraneoplastic syndromes, compared the prevalence of these syndromes between cases of hepatitis B virus (HBV)-related and hepatitis C virus (HCV)-related HCC, and estimated significant predictors associated with the syndromes.

METHODS

Clinical data on 1197 HCC patients, including age, gender, Child-Pugh score, survival time, laboratory data (including liver biochemistry, hepatitis markers, and serum alpha-fetoprotein [AFP]), and tumor features (including tumor size, portal vein thrombosis, and histologic pictures), were retrospectively reviewed.

RESULTS

A total of 232 of 1197 patients (19.4%) had paraneoplastic syndromes. HCC patients with paraneoplastic syndromes had significantly higher serum AFP; higher rates of initial main portal vein thrombosis, metastasis, and bilobal tumor involvement; larger tumor volume; and shorter survival than those without these syndromes. Patients with HBV-related HCC had a significantly higher prevalence of paraneoplastic syndromes than patients with HCV-related HCC (20.1% vs. 11.2%, P = 0.005). In a stepwise multivariate logistic regression analysis, AFP >50,000 ng/mL and tumor volume >30% were significant predictive variables associated with the presence of paraneoplastic syndromes in HCC patients.

CONCLUSIONS

HCC patients with paraneoplastic syndromes usually had higher levels of serum AFP and larger tumor volumes than those without. Patients with HBV-related HCC had a significantly higher prevalence of paraneoplastic syndromes than those with HCV-related HCC.

Prolonged bleeding time: a new clinical manifestation of hepatocellular carcinoma?

The association between prolonged bleeding time and hepatocellular carcinoma (HCC) has not been well studied. We investigated whether bleeding time is prolonged in cirrhotic patients with HCC and studied the role of clinical characteristics, tumour size, and laboratory data in predicting bleeding time prolongation. After excluding patients that presented with blood dyscrasia and uraemia, 58 cirrhotic patients with HCC, 106 cirrhotic patients without HCC, and 44 age-and sex-matched healthy subjects were included in the study. Bleeding time, imaging studies, clinical characteristics and biochemical data were obtained for every patient. Cirrhotic patients with and without HCC had longer bleeding times (554 +/- 32 s, respectively) compared with healthy controls (357 +/- 13 s, P < 0.05). Hepatocellular carcinoma patients with a large tumour burden (> 5 cm in diameter) had a significantly longer bleeding time than those patients without (663 +/- 105 vs 376 +/- 23 s, respectively, P < 0.05). After excluding patients with a platelet count < or = 80 000/mm3, cirrhotic patients classified as Child-Pugh's grading A and with a large tumour burden had longer bleeding times(580 +/- 87 s) than patients with a small tumour burden (< or = 5cm in diameter) and cirrhotic patients without HCC (371 +/- 22 and 416 +/- 29 s, respectively, P < 0.05). In cirrhotic patients with HCC, higher serum bilirubin levels, a Child-Pugh's grading C, and a tumour size > 5 cm in diameter were found to be significant predictors for prolonged bleeding time on univariate analysis. On multivariate analysis, both tumour size > 5 cm in diameter and a Child-Pugh's grading C (odd's ratio, 95% confidence interval and P value were measured as 38.5, 2.8-534.7, < 0.001, and 10.5, 0.9-117.6, 0.02, respectively) were the significant independent predictors. A significant correlation existed between tumour diameter and bleeding time (r = 0.44, P < 0.01). In conclusion, these results suggest that prolonged bleeding time may be categorized as a new clinical manifestation in patients with HCC. In addition to cirrhosis, HCC itself may also participate in the pathogenesis of bleeding time prolongation.

Tumor-induced hypercalcemia and parathyroid hormone-related protein in lung carcinoma

BACKGROUND

Although lung carcinoma is the most common cause of tumor-induced hypercalcemia (TIH), the precise incidence of TIH remains obscure. Furthermore, the role of parathyroid hormone-related protein (PTHrP) has not been clearly elucidated.

METHODS

This study included 690 consecutive patients who were newly diagnosed as having lung carcinoma between 1989 and 1994 (379 adenocarcinomas, 207 squamous cell carcinomas, 75 small cell carcinomas, and 29 large cell carcinomas). All patients were treated for lung carcinoma and were also periodically monitored for their serum level of calcium (Ca). Hypercalcemia was defined as a serum Ca concentration higher than 11 mg/dL. The serum levels of PTHrP (109-141) were measured by a C-terminal-region-specific radioimmunoassay.

RESULTS

TIH was observed in 17 of 690 patients (2.5%). All 17 patients demonstrated an advanced stage of lung carcinoma (Stage III or IV), 10 squamous cell carcinomas, 5 adenocarcinomas, 1 small cell carcinoma, and 1 large cell carcinoma. In 15 patients, the serum level of C-PTHrP (109-141) was substantially high, ranging from 99 pmol/L to 890 pmol/L (normal range, 21-50.7 pmol/L). There was no significant difference in the serum PTHrP level between patients with or without bone metastasis. The reduction of tumor burden decreased both the serum level of PTHrP and that of Ca in parallel. The median survival time after diagnosis of TIH was only 27 days.

CONCLUSIONS

TIH in lung carcinoma was most likely attributable to PTHrP, and its occurrence appears to be an ominous prognostic sign.

Distribution and functions of parathyroid hormone-related protein in vertebrate cells

Parathyroid hormone-related protein (PTHrP) was isolated from tumors and identified as the agent of humoral hypercalcemia of malignancy (HHM) in 1987. Since then its gene structure in several mammalian and an avian species has been analyzed and its gene expression demonstrated in many adult and embryonic tissues derived from all three germ layers. The composition and structure of PTHrP peptide depends on both differential gene splicing and posttranslational processing, which result in a range of peptides of potentially diverse functions. This chapter describes the distribution of PTHrP in both normal and neoplastic adult and embryonic tissues. PTHrP is of fundamental importance to cell survival because the absence of the gene is fatal; this aspect of PTHrP function in cell physiology becomes overwhelmingly important in neoplasia. Intracrine or paracrine actions for PTHrP seem to be most likely in mammalian and avian physiology, but in fishes high circulating levels suggest classic endocrine functions as well. Much remains to be learned of the biology of this fascinating protein.