Sonographic screening for hepatocellular carcinoma in patients with chronic hepatitis or cirrhosis: an evaluation

A Systematic Review and Narrative Synthesis of Health Economic Evaluations of Hepatocellular Carcinoma Screening Strategies

OBJECTIVES

Many economic evaluations of hepatocellular carcinoma (HCC) screenings have been conducted; however, these vary substantially with regards to screening strategies, patient group, and setting. This review aims to report the current knowledge of the cost-effectiveness of screening and describe the published data.

METHODS

We conducted a search of biomedical and health economic databases up to July 2020. We included full and partial health economic studies if they evaluated the costs or outcomes of HCC screening strategies.

RESULTS

The review included 43 studies. Due to significant heterogeneity in key aspects across the studies, a narrative synthesis was conducted. Most studies reported using ultrasound or alpha fetoprotein as screening strategies. Screening intervals were mostly annual or biannual. Incidence, diagnostic performance, and health state utility values were the most critical parameters affecting the cost-effectiveness of screening. The majority of studies reported HCC screening to be cost-effective, with the biannual ultrasound + alpha fetoprotein standing out as the most cost-effective strategy. However, few studies considered the utilization rate, and none considered the diagnostic performance of ultrasound in the context of central adiposity. Computed tomography and magnetic resonance imaging were also evaluated, but its cost-effectiveness was still controversial.

CONCLUSIONS

Although many studies suggested HCC screening was cost-effective, substantial limitations of the quality of these studies means the results should be interpreted with caution. Future modeling studies should consider the impact of central adiposity on the precision of ultrasound, real-world utilization rates and projections of increased HCC incidence.

Abdominal ultrasound and alpha-foetoprotein for the diagnosis of hepatocellular carcinoma in adults with chronic liver disease

BACKGROUND

Hepatocellular carcinoma (HCC) occurs mostly in people with chronic liver disease and ranks sixth in terms of global instances of cancer, and fourth in terms of cancer deaths for men. Despite that abdominal ultrasound (US) is used as an initial test to exclude the presence of focal liver lesions and serum alpha-foetoprotein (AFP) measurement may raise suspicion of HCC occurrence, further testing to confirm diagnosis as well as staging of HCC is required. Current guidelines recommend surveillance programme using US, with or without AFP, to detect HCC in high-risk populations despite the lack of clear benefits on overall survival. Assessing the diagnostic accuracy of US and AFP may clarify whether the absence of benefit in surveillance programmes could be related to under-diagnosis. Therefore, assessment of the accuracy of these two tests for diagnosing HCC in people with chronic liver disease, not included in surveillance programmes, is needed.

OBJECTIVES

Primary: the diagnostic accuracy of US and AFP, alone or in combination, for the diagnosis of HCC of any size and at any stage in adults with chronic liver disease, either in a surveillance programme or in a clinical setting. Secondary: to assess the diagnostic accuracy of abdominal US and AFP, alone or in combination, for the diagnosis of resectable HCC; to compare the diagnostic accuracy of the individual tests versus the combination of both tests; to investigate sources of heterogeneity in the results.

SEARCH METHODS

We searched the Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Hepato-Biliary Group Diagnostic-Test-Accuracy Studies Register, Cochrane Library, MEDLINE, Embase, LILACS, Science Citation Index Expanded, until 5 June 2020. We applied no language or document-type restrictions.

SELECTION CRITERIA

Studies assessing the diagnostic accuracy of US and AFP, independently or in combination, for the diagnosis of HCC in adults with chronic liver disease, with cross-sectional and case-control designs, using one of the acceptable reference standards, such as pathology of the explanted liver, histology of resected or biopsied focal liver lesion, or typical characteristics on computed tomography, or magnetic resonance imaging, all with a six-months follow-up.

DATA COLLECTION AND ANALYSIS

We independently screened studies, extracted data, and assessed the risk of bias and applicability concerns, using the QUADAS-2 checklist. We presented the results of sensitivity and specificity, using paired forest-plots, and tabulated the results. We used a hierarchical meta-analysis model where appropriate. We presented uncertainty of the accuracy estimates using 95% confidence intervals (CIs). We double-checked all data extractions and analyses.

MAIN RESULTS

We included 373 studies. The index-test was AFP (326 studies, 144,570 participants); US (39 studies, 18,792 participants); and a combination of AFP and US (eight studies, 5454 participants). We judged at high-risk of bias all but one study. Most studies used different reference standards, often inappropriate to exclude the presence of the target condition, and the time-interval between the index test and the reference standard was rarely defined. Most studies with AFP had a case-control design. We also had major concerns for the applicability due to the characteristics of the participants. As the primary studies with AFP used different cut-offs, we performed a meta-analysis using the hierarchical-summary-receiver-operating-characteristic model, then we carried out two meta-analyses including only studies reporting the most used cut-offs: around 20 ng/mL or 200 ng/mL. AFP cut-off 20 ng/mL: for HCC (147 studies) sensitivity 60% (95% CI 58% to 62%), specificity 84% (95% CI 82% to 86%); for resectable HCC (six studies) sensitivity 65% (95% CI 62% to 68%), specificity 80% (95% CI 59% to 91%). AFP cut-off 200 ng/mL: for HCC (56 studies) sensitivity 36% (95% CI 31% to 41%), specificity 99% (95% CI 98% to 99%); for resectable HCC (two studies) one with sensitivity 4% (95% CI 0% to 19%), specificity 100% (95% CI 96% to 100%), and one with sensitivity 8% (95% CI 3% to 18%), specificity 100% (95% CI 97% to 100%). US: for HCC (39 studies) sensitivity 72% (95% CI 63% to 79%), specificity 94% (95% CI 91% to 96%); for resectable HCC (seven studies) sensitivity 53% (95% CI 38% to 67%), specificity 96% (95% CI 94% to 97%). Combination of AFP (cut-off of 20 ng/mL) and US: for HCC (six studies) sensitivity 96% (95% CI 88% to 98%), specificity 85% (95% CI 73% to 93%); for resectable HCC (two studies) one with sensitivity 89% (95% CI 73% to 97%), specificity of 83% (95% CI 76% to 88%), and one with sensitivity 79% (95% CI 54% to 94%), specificity 87% (95% CI 79% to 94%). The observed heterogeneity in the results remains mostly unexplained, and only in part referable to different cut-offs or settings (surveillance programme compared to clinical series). The sensitivity analyses, excluding studies published as abstracts, or with case-control design, showed no variation in the results. We compared the accuracy obtained from studies with AFP (cut-off around 20 ng/mL) and US: a direct comparison in 11 studies (6674 participants) showed a higher sensitivity of US (81%, 95% CI 66% to 90%) versus AFP (64%, 95% CI 56% to 71%) with similar specificity: US 92% (95% CI 83% to 97%) versus AFP 89% (95% CI 79% to 94%). A direct comparison of six studies (5044 participants) showed a higher sensitivity (96%, 95% CI 88% to 98%) of the combination of AFP and US versus US (76%, 95% CI 56% to 89%) with similar specificity: AFP and US 85% (95% CI 73% to 92%) versus US 93% (95% CI 80% to 98%).

AUTHORS' CONCLUSIONS

In the clinical pathway for the diagnosis of HCC in adults, AFP and US, singularly or in combination, have the role of triage-tests. We found that using AFP, with 20 ng/mL as a cut-off, about 40% of HCC occurrences would be missed, and with US alone, more than a quarter. The combination of the two tests showed the highest sensitivity and less than 5% of HCC occurrences would be missed with about 15% of false-positive results. The uncertainty resulting from the poor study quality and the heterogeneity of included studies limit our ability to confidently draw conclusions based on our results.

Label-free detection of biomarker alpha fetoprotein in serum by ssDNA aptamer functionalized magnetic nanoparticles

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors in the clinic, with the characteristics of occult onset, rapid progression, and high degree of malignancy. Alpha fetoprotein (AFP) is the most important biomarker of HCC, which is widely used in early screening, diagnosis, and prognosis observation. A series of immunoassays have been developed and frequently used in the detection of AFP based on antibodies. Unfortunately, the shortcomings of antibodies, such as thermal unstable and fluctuant activity by batches, lead to the inaccuracy in the detection of AFP. In this study, aptamers instead of antibodies were adopted as the specific recognition element for AFP, aiming to seek an alternative strategy to immunoassays. An AFP-specific ssDNA aptamer was grafted to magnetic nanoparticles (Fe₃O₄@SiO₂) via avidin-biotin interaction, and the resultant aptamer functionalized magnetic nanoparticles (Ap-MNPs) were adequately characterized and tested. The Ap-MNPs in solution exhibited a fast response to the outer magnetic field, and can be completely separated in several minutes. It was found that Ap-MNPs have good specificity to the target AFP, as the recovery of AFP (87.0%) was much higher than the competitive proteins IgG (38.9%), HSA (18.5%), and FIB (11.4%). A convenient and efficient label-free detection method of AFP in serum was developed based on Ap-MNPs in combination with high-performance liquid chromatography. The linearity of this method was over a range of 1-50 μg ml^-1 with a correlation coefficient of 0.9999, and the limit of detection was 0.27 μg ml^-1. This study indicated that aptamers are an ideal tool for the recognition and detection of biomarkers, and thus will find wide applications in clinical practice.

Surveillance Imaging and Alpha Fetoprotein for Early Detection of Hepatocellular Carcinoma in Patients With Cirrhosis: A Meta-analysis

BACKGROUND & AIMS

Society guidelines differ in their recommendations for surveillance to detect early-stage hepatocellular carcinoma (HCC) in patients with cirrhosis. We compared the performance of surveillance imaging, with or without alpha fetoprotein (AFP), for early detection of HCC in patients with cirrhosis.

METHODS

Two reviewers searched MEDLINE and SCOPUS from January 1990 through August 2016 to identify published sensitivity and specificity of surveillance strategies for overall and early detection of HCC. Pooled estimates were calculated and compared using the DerSimonian and Laird method for a random effects model. The study was conducted in accordance with Preferred Reporting Items for Systematic Review and Meta-analysis guidelines.

RESULTS

Thirty-two studies (comprising 13,367 patients) characterized sensitivity of imaging with or without AFP measurement for detection of HCC in patients with cirrhosis. Ultrasound detected any stage HCC with 84% sensitivity (95% confidence interval [CI] 76%-92%), but early-stage HCC with only 47% sensitivity (95% CI 33%-61%). In studies comparing ultrasound with vs without AFP measurement, ultrasound detected any stage HCC with a lower level of sensitivity than ultrasound plus AFP measurement (relative risk [RR] 0.88; 95% CI 0.83-0.93) and early-stage HCC with a lower level of sensitivity than ultrasound plus AFP measurement (RR 0.81; 95% CI 0.71-0.93). However, ultrasound alone detected HCC with a higher level of specificity than ultrasound plus AFP measurement (RR 1.08; 95% CI 1.05-1.09). Ultrasound with vs without AFP detected early-stage HCC with 63% sensitivity (95% CI 48%-75%) and 45% sensitivity (95% CI 30%-62%), respectively (P = .002). Only 4 studies evaluated computed tomography or magnetic resonance image-based surveillance, which detected HCC with 84% sensitivity (95% CI 70%-92%).

CONCLUSIONS

We found ultrasound alone has a low sensitivity to detect early stage HCC in patients with cirrhosis. Addition of AFP to ultrasound significantly increases sensitivity of early HCC detection in clinical practice.

Screening and Surveillance of Hepatocellular Carcinoma: An Introduction to Ultrasound Liver Imaging Reporting and Data System

Given the high prevalence, increasing incidence, and significant morbidity and mortality related to hepatocellular carcinoma (HCC), a robust and cost-effective screening and surveillance program is needed. Most societies recommend ultrasound for HCC screening, despite lack of standardization in imaging acquisition, reporting content and language, and follow-up recommendations. The American College of Radiology Ultrasound Liver Imaging Reporting and Data System (US LI-RADS) fills this unmet need by providing standardization in the use of US in at-risk patients. It is anticipated that US LI-RADS will improve the performance of ultrasound for HCC screening and surveillance and unify management recommendations.

The Use of Contrast-Enhanced Ultrasonography for the Characterization of Focal Liver Lesions

Focal liver lesions often occur with or without an underlying liver disease. Contrast-enhanced ultrasonography can aid in characterizing liver lesions, potentially avoiding biopsy and computed tomography procedures. Contrast-enhanced ultrasonography has a high sensitivity and specificity for differentiating characteristics of liver lesions compared with noncontrast sonography. The different contrast characteristics aid in differentiating benign and malignant lesions. Malignant lesions tend to have washout of contrast in the venous phases, whereas benign lesions have hyperenhancement during the venous phases. Therefore, contrast-enhanced ultrasonography should be considered an essential component of the diagnostic process for diagnosing and following focal liver lesions.

Diffusion-weighted MRI for hepatocellular carcinoma screening in chronic liver disease: Direct comparison with ultrasound screening

INTRODUCTION

Ultrasound is a widely utilized method of screening patients with chronic liver disease for hepatocellular carcinoma (HCC). However, the sensitivity of ultrasound for small tumours is limited. We have prospectively compared ultrasound screening with diffusion-weighted (DWI) MRI for detecting HCC.

METHODS

Patients with chronic liver disease referred for ultrasound screening underwent a liver ultrasound and a liver MRI comprising free breathing DWI. Each test was independently read to determine the accuracy of each modality for detecting HCC.

RESULTS

One hundred and ninety-two patients were recruited and HCC was diagnosed in six patients (3%); all of whom were detected at ultrasound screening, and five detected at MRI screening. Ultrasound had false-positive studies 20 times (10%) while DWI MRI had three false-positive examinations (2%) p≥0.05. The sensitivity, specificity, positive predictive value and negative predictive values for ultrasound are 100%, 90%, 23% and 100%, respectively, while for MRI are 83%, 98%, 63% and 99%.

CONCLUSION

In patients with chronic liver disease undergoing surveillance for hepatocellular carcinoma, DWI MRI screening shows similar sensitivity to screening ultrasound but with a significantly lower false-positive rate.

Early diagnosis of liver cancer: an appraisal of international recommendations and future perspectives

All Societies, AASLD, EASL, APASL and JSH, identify patients with cirrhosis as a target population for surveillance, with minor differences for additional categories of patients, such as chronic hepatitis B and hepatitis C patients with advanced fibrosis. According to AASLD, liver disease related to metabolic diseases including diabetes and obesity is a recognized target of screening, since those conditions have been causally related to HCC. All societies endorse radiological non-invasive techniques as the mainstay for early diagnosis of HCC, but discrepancies exist between Societies on the utilization of contrast-enhanced ultrasound and utilization of serum markers for surveillance and diagnosis of HCC. The diagnostic algorithm of the international societies differ substantially in the anatomic paradigm of EASL and APASL which identify 1 cm size as the starting point for radiological diagnosis of HCC compared to APASL algorithm based on the dynamic pattern of contrast imaging, independently on tumour size. While strengthening prediction in individual patients is expected to improve cost-effectiveness ratios of screening, the benefits of pre-treatment patient stratification by clinical, histological and genetic scores remain uncertain and exclusion of patients with severe co-morbidities and advanced age is still debated.

Ultrasound imaging of the liver and bile ducts - expectations of a clinician

Since diseases of the liver and bile ducts are common, a clinician is faced by the need to implement an appropriate diagnostic process. It is necessary to apply diagnostic methods that enable appropriate assessment of the most common pathologies of the liver, i.e. fibrosis, steatosis and focal lesions, as well as initial assessment of the bile ducts. These goals can be achieved using ultrasound methods based on conventional sonography, contrast-enhanced sonography and elastography. The assessment of fatty liver and bile duct dilatation using ultrasound reaches satisfactory levels of sensitivity and specificity. The usage of contrast agents enables unambiguous differentiation between benign and malignant focal lesions, frequently allowing them to be identified accurately without the assistance of other imaging modalities. Elastography has enabled reliable assessment of liver fibrosis. Its results are comparable to those of the standard method, i.e. liver biopsy.

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.

In vivo application of short-lag spatial coherence imaging in human liver

We present the results of a patient study conducted to assess the performance of two novel imaging methods, namely short-lag spatial coherence (SLSC) and harmonic spatial coherence imaging (HSCI), in an in vivo liver environment. Similar in appearance to the B-mode images, SLSC and HSCI images are based solely on the spatial coherence of fundamental and harmonic echo data, respectively, and do not depend on the echo magnitude. SLSC and HSCI suppress incoherent echo signals and thus tend to reduce clutter. The SLSC and HSCI images of 17 patients demonstrated sharper delineation of blood vessel walls, suppressed clutter inside the vessel lumen, and showed reduced speckle in surrounding tissue compared to matched B-modes. Target contrast and contrast-to-noise ratio (CNR) show statistically significant improvements between fundamental B-mode and SLSC imaging and between harmonic B-mode and HSCI imaging (in all cases p < 0.001). The magnitude of improvement in contrast and CNR increases as the overall quality of B-mode images decreases. Poor-quality fundamental B-mode images (where image quality classification is based on both contrast and CNR) exhibit the highest improvements in both contrast and CNR (288% improvement in contrast and 533% improvement in CNR).

Surveillance for hepatocellular carcinoma

The only hope for a cure from hepatocellular carcinoma (HCC) rests on early diagnosis as it can be attained through semiannual surveillance with abdominal ultrasound (US) of patients at risk. While the strategy of semiannual screening rests on the growth rate of the tumor that in cirrhotic patients takes 6 months to double its volume, on average, the noninvasive radiological diagnosis of HCC is possible in cirrhotic patients with a de novo HCC and patients with chronic hepatitis B. More recently, metabolic diseases related to insulin resistance, including diabetes and obesity, have been recognized to be causally related to HCC as well, in most patients bridging HCC to the histopathological diagnosis of non-alcoholic steatohepatitis (NASH). While the endpoint of an early diagnosis is achieved quite easily in most patients with >1 cm HCC by computed tomography (CT) or magnetic resonance imaging (MRI) demonstrating the specific pattern of an intense contrast uptake during the arterial phase (wash-in) and contrast wash-out during the venous/delayed phase, nodules <1 cm in size are more difficult to diagnose, almost invariably requiring an enhanced follow up with three monthly examinations with US until they grow in size or change their echo pattern. Owing to the lack of robust controlled evidence demonstrating a clinical benefit of surveillance, the real support for screening for liver cancer comes from the striking differences in response to therapy between screened populations in whom HCC is diagnosed and treated at early stages and patients with more advanced, incidentally detected tumors. This notwithstanding, numerous barriers work against screening effectiveness, including limited or outdated knowledge, lack of financial incentives, and limited access to appropriate testing and treatment. Though strengthening prediction in individual patients is expected to improve the cost-effectiveness ratio of screening, the benefits of approaches like pretreatment patient stratification by clinical, histologic, and genetic scores remain uncertain, while the worthiness of excluding patients with severe comorbidities and aged individuals is still debated.

Multidisciplinary Canadian consensus recommendations for the management and treatment of hepatocellular carcinoma

Globally, hepatocellular carcinoma (hcc) is the third most common cause of death from cancer, after lung and stomach cancer. The incidence of hcc in Canada is increasing and is expected to continue to increase over the next decade. Given the high mortality rate associated with hcc, steps are required to mitigate the impact of the disease. To address this challenging situation, a panel of 17 hcc experts, representing gastroenterologists, hepatologists, hepatobiliary surgeons, medical oncologists, pathologists, and radiologists from across Canada, convened to provide a framework that, using an evidence-based approach, will assist clinicians in optimizing the management and treatment of hcc. The recommendations, summarized here, were developed based on a rigorous methodology in a pre-specified process that was overseen by the steering committee. Specific topics were identified by the steering committee and delegated to a group of content experts within the expert panel, who then systematically reviewed the literature on that topic and drafted the related content and recommendations. The set of recommendations for each topic were reviewed and assigned a level of evidence and grade according to the levels of evidence set out by the Centre for Evidence-based Medicine, Oxford, United Kingdom. Agreement on the level of evidence for each recommendation was achieved by consensus. Consensus was defined as agreement by a two-thirds majority of the 17 members of the expert panel. Recommendations were subject to iterative review and modification by the expert panel until consensus could be achieved.

Hepatocellular carcinoma: screening and staging

Active screening of patients at risk for HCC has led to the identification of early HCCs that are amenable to treatment with a high rate of cure. This requires high-quality ultrasound examinations at 6-month intervals. If widely applied, screening has the potential to substantially reduce the mortality from this disease. The application of the Barcelona Cancer of the Liver Clinic (BCLC) staging system should standardize assessment of prognosis and determination of the most effective treatments for each stage. With new molecular targeted agents coming, it is critical that studies are performed in patients stratified by stage into homogeneous groups. Because it is linked with therapy, the BCLC is ideally suited to this purpose.

Contrast-enhanced ultrasound for characterisation of hepatic lesions appearing non-hypervascular on CT in chronic liver diseases

OBJECTIVES

The purpose of this prospective study was to elucidate the efficacy of using contrast-enhanced ultrasound to characterise focal hepatic lesions appearing non-hypervascular on contrast-enhanced CT in chronic liver diseases.

METHODS

The study population included 22 patients with cirrhosis or chronic hepatitis, who between them had 27 focal hepatic lesions smaller than 20 mm (mean 13.9 ± 3.4) that appeared non-hypervascular on contrast-enhanced CT. Contrast-enhanced ultrasound with perflubutane microbubble agent (Sonazoid, 0.0075 ml kg(-1)) was performed prior to ultrasound-guided needle biopsy, and intensity analysis was done for hepatic lesions in the early phase (-60 s) and late phase (600 s post injection).

RESULTS

All seven early-phase hyperenhanced lesions were hepatocellular carcinoma (HCC). 20 lesions iso- or hypoenhanced during the early phase consisted of 11 regenerative nodules (RNs) and 9 HCCs. HCC was more frequent in early-phase hyperenhanced lesions than in iso- or hypoenhanced lesions (p=0.0108). Both late-phase hypoenhanced lesions were HCCs, whereas 25 late-phase isoenhanced lesions consisted of 11 RNs and 14 HCCs. The enhancement patterns of the 11 RNs included isoenhanced appearance in both the early and late phases in 8 lesions, and early-phase hypoenhancement combined with late-phase isoenhancement in the remaining 3. Both of these enhancement patterns (i.e. either iso-iso or hypo-iso) were found in 9 malignant lesions, 9 (75%) of the 12 well-differentiated HCCs.

CONCLUSION

Hypervascularity on contrast-enhanced ultrasound with Sonazoid strongly suggested HCC regardless of non-hypervascularity on CT, and late-phase hypoenhancement was another possible finding of HCC. However, characterisation of hepatic lesions with other enhancement patterns was difficult using our technique.

APASL and AASLD Consensus Guidelines on Imaging Diagnosis of Hepatocellular Carcinoma: A Review

Consensus guidelines for radiological diagnosis of hepatocellular carcinoma (HCC) have been drafted by several large international working groups. This article reviews the similarities and differences between the most recent guidelines proposed by the American Association for Study of Liver Diseases and the Asian Pacific Association for the Study of the Liver. Current evidence for the various imaging modalities for diagnosis of HCC and their relevance to the consensus guidelines are reviewed.

Cost-effectiveness analysis of a two-stage screening intervention for hepatocellular carcinoma in Taiwan

BACKGROUND/PURPOSE

Hepatocellular carcinoma (HCC) has been the leading cause of cancer death in Taiwan since the 1980s. A two-stage screening intervention was introduced in 1996 and has been implemented in a limited number of hospitals. The present study assessed the costs and health outcomes associated with the introduction of screening intervention, from the perspective of the Taiwanese government. The cost-effectiveness analysis aimed to assist informed decision making by the health authority in Taiwan.

METHODS

A two-phase economic model, 1-year decision analysis and a 60-year Markov simulation, was developed to conceptualize the screening intervention within current practice, and was compared with opportunistic screening alone. Incremental analyses were conducted to compare the incremental costs and outcomes associated with the introduction of the intervention. Sensitivity analyses were performed to investigate the uncertainties that surrounded the model.

RESULTS

The Markov model simulation demonstrated an incremental cost-effectiveness ratio (ICER) of NT$498,000 (US$15,600) per life-year saved, with a 5% discount rate. An ICER of NT$402,000 (US$12,600) per quality-adjusted life-year was achieved by applying utility weights. Sensitivity analysis showed that excess mortality reduction of HCC by screening and HCC incidence rates were the most influential factors on the ICERs. Scenario analysis also indicated that expansion of the HCC screening intervention by focusing on regular monitoring of the high-risk individuals could achieve a more favorable result.

CONCLUSION

Screening the population of high-risk individuals for HCC with the two-stage screening intervention in Taiwan is considered potentially cost-effective compared with opportunistic screening in the target population of an HCC endemic area.

National Academy of Clinical Biochemistry Laboratory Medicine Practice Guidelines for use of tumor markers in liver, bladder, cervical, and gastric cancers

BACKGROUND

Updated National Academy of Clinical Biochemistry Laboratory Medicine Practice Guidelines for the use of tumor markers in the clinic have been developed.

METHODS

Published reports relevant to use of tumor markers for 4 cancer sites--liver, bladder, cervical, and gastric--were critically reviewed.

RESULTS

Alpha-fetoprotein (AFP) may be used in conjunction with abdominal ultrasound for early detection of hepatocellular carcinoma (HCC) in patients with chronic hepatitis or cirrhosis associated with hepatitis B or C virus infection. AFP concentrations >200 microg/L in cirrhotic patients with typical hypervascular lesions >2 cm in size are consistent with HCC. After a diagnosis of HCC, posttreatment monitoring with AFP is recommended as an adjunct to imaging, especially in the absence of measurable disease. Although several urine markers have been proposed for bladder cancer, none at present can replace routine cystoscopy and cytology in the management of patients with this malignancy. Some may, however, be used as complementary adjuncts to direct more effective use of clinical procedures. Although carcinoembryonic antigen and CA 19-9 have been proposed for use gastric cancer and squamous cell carcinoma antigen for use in cervical cancer, none of these markers can currently be recommended for routine clinical use.

CONCLUSIONS

Implementation of these recommendations should encourage optimal use of tumor markers for patients with liver, bladder, cervical, or gastric cancers.

Changes in tumor vascularity precede microbubble contrast accumulation deficit in the process of dedifferentiation of hepatocellular carcinoma

PURPOSE

To elucidate the changes in tumor vascularity and microbubble accumulation on contrast-enhanced sonograms, in relation to the dedifferentiation of hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

This prospective study enrolled 10 patients with histologically proven HCC (14.4-39.0mm, 26.1+/-7.4) showing nodule-in-nodule appearance upon contrast-enhanced computed tomography. Contrast-enhanced ultrasound was performed by harmonic imaging under a low mechanical index (0.22-0.25) during the vascular phase (agent injection to 1 min) and late phase (15 min) following the injection of Sonazoid (0.0075 ml/kg). Contrast enhancement in the inner and outer nodules was assessed in comparison with that in adjacent liver parenchyma as hyper-, iso-, or hypo-enhanced.

RESULTS

Vascular-phase enhancement of all 10 inner nodules was hyper-enhanced, and that of outer nodules was hyper-enhanced in 3, iso-enhanced in 2, and hypo-enhanced in 5. Late-phase enhancement of inner nodules was hypo-enhanced in 8 and iso-enhanced in 2. Furthermore, late-phase enhancement of outer nodules was iso-enhanced in the 7 lesions that showed iso- or hypo-enhancement in the vascular phase, and hypo-enhanced in the 3 with hyper-enhancement in the vascular phase. Late-phase hypo-enhancement was significantly more frequent in the nodules showing early-phase hyper-enhancement (11/13) than in the nodules showing early-phase iso- or hypo-enhancement (0/7) in both the inner and outer nodules.

CONCLUSION

Dedifferentiation of HCC may be accompanied by changes in tumor vascularity prior to a reduction in microbubble accumulation. Observation of the vascular phase may be more useful than late-phase imaging for the early recognition of HCC dedifferentiation when using contrast-enhanced ultrasound with Sonazoid.

Review of Asian experience of thermal ablation techniques and clinical practice

The field of image-guided tumour ablation has gained great attention from Asian physicians because it represents a safe and effective technique for many commonly seen tumours in this population, showing minimal morbidity and excellent local control rates. Based on the current survey data from Asian physicians who are currently performing image-guided tumour ablation, thermal ablation has been mainly performed for patients with unresectable liver tumours. Radiofrequency ablation has replaced many other local ablation techniques such as microwave or ethanol ablation in treating small focal hepatic tumours for the last 5 years. Surgery and transcatheter arterial chemoembolization also have a unique role as curative and palliative treatment options for patients with more extensive tumour burden. Although radiofrequency ablation represents a paradigm shift in local therapy, more sophisticated strategies to enhance the therapeutic efficacy are necessary and more randomized and controlled investigations to estimate its clinical benefit are warranted.

Modern diagnosis and management of hepatocellular carcinoma

The incidence of hepatocellular carcinoma (HCC) is rising, and the number of patients with HCC is expected to more than double over the next 1 to 2 decades. HCC meets the criteria for establishment of a surveillance program. Patients with cirrhosis, regardless of the cause, are at the highest risk for developing HCC and this is the population in which surveillance should be performed. (Alpha-fetoprotein and hepatic ultrasonography are the currently recommended surveillance tests. If a surveillance test is abnormal, there is a need for a recall test for diagnostic evaluation of HCC. Triple-phase imaging is recommended for evaluation at recall, with MRI being more sensitive and specific. Novel genetic markers can improve the histologic diagnosis of early HCC. The Barcelona staging classification is the best system for determining the prognosis of patients and it is linked to an evidence-based treatment algorithm. Resection, transplantation, and percutaneous ablation are considered curative interventions and are currently applied to about 30% of all patients with HCC.

Undiagnosed cirrhosis occurs frequently in the elderly and requires periodic follow ups and medical treatments

BACKGROUND

Autopsy examinations frequently reveal undiagnosed cirrhosis, but its characteristics have rarely been addressed in the elderly.

METHODS

From 1597 consecutive autopsies, those of patients with liver cirrhosis were selected and their clinicopathological findings were examined.

RESULTS

Seventy-six patients had liver cirrhosis; 18 of these patients (23.7%) were classified as an "undiagnosed" group and in that they had not been diagnosed as having cirrhosis before death. The remaining 58 patients were classified as a "clinical" group. Compared to the clinical group, the undiagnosed group demonstrated a significantly lower Child-Pugh score (7.1 +/- 1.9 vs 8.6 +/- 2.1; P < 0.01) and infrequent hepatocellular carcinoma (72.4% vs 5.6%; P < 0.0001). The undiagnosed group also demonstrated significantly lower complication rates of hepatic encephalopathy and esophageal varix, and a volume of ascites. The patients in the undiagnosed group were significantly older (79.9 +/- 8.1 vs 74.2 +/- 8.5 years; P < 0.01), and fewer patients died of liver-related causes (17% vs 67.2%; P < 0.0001). The etiology of cirrhosis was unknown in five patients in the undiagnosed group, and seven patients did not show any suggestive symptoms or imaging signs.

CONCLUSION

Liver cirrhosis is often undiagnosed (23.7%) in the elderly. In the undiagnosed group, liver function was preserved and serious complications were infrequent. Because the diagnosis of cirrhosis leads to early identification of hepatocellular carcinoma and good prognosis, detailed examination and periodic follow ups should be performed when liver dysfunction is indicated, even in the elderly.

Current role of ultrasound for the management of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) has a decisive influence on the prognosis of cirrhotic patients. Although α-fetoprotein (AFP) is a known and specific tumor maker for HCC, it is not suitable for the screening and surveillance of HCC because of its poor predictive value and low sensitivity. The use of imaging modalities is essential for the screening, diagnosis and treatment of HCC. Ultrasound (US) plays a major role among them, because it provides real-time and non-invasive observation by a simple and easy technique. In addition, US-guided needle puncture methods are frequently required for the diagnosis and/or treatment process of HCC. The development of digital technology has led to the detection of blood flow by color Doppler US, and the sensitivity for detecting tumor vascularity has shown remarkable improvement with the introduction of microbubble contrast agents. Moreover, near real-time 3-dimensional US images are now available. As for the treatment of HCC, high intensity focused ultrasound (HIFU) was developed as a novel technology that provides a transcutaneous ablation effect without needle puncture. These advancements in the US field have led to rapid progress in HCC management, and continuing advances are expected. This article reviews the current application of US for HCC in clinical practice.

Development of high-performance magnetic chemiluminescence enzyme immunoassay for alpha-fetoprotein (AFP) in human serum

BACKGROUND

A high-performance chemiluminescence enzyme immunoassay (CLEIA) for alpha-fetoprotein (AFP), a tumor marker for the diagnosis of hepatocellular carcinoma (HCC), was constructed by using magnetic particles (MPs) as both the immobilization matrix and separation tools.

METHODS

A double sandwiched immunocomplex was formed through the reaction among anti-fluorescein isothiocyanate (FITC) antibody coated MPs, FITC-labeled anti-AFP antibody, AFP antigen, and alkaline phosphatase (ALP)-labeled anti-AFP antibody. The subsequent chemiluminescence reaction of ALP with 4-methoxy-4-(3-phosphate-phenyl)-spiro-(1,2-dioxetane-3,2'-adamantane) (AMPPD) gave light intensity that was directly proportional to the amount of analyte present in the samples. The effects of several physicochemical parameters, including the concentration of FITC-labeled anti-AFP antibody, the dilution ratio of ALP-labeled anti-AFP antibody, the volume of MPs and substrate, the immunoreaction time and other relevant variables upon the immunoassay were studied and optimized. RIA and microplate CLEIA were used as comparison methods.

RESULTS

The proposed method had a sensitivity of 3.0 ng/ml, low cross reactivities, and an assay time of 1 h. The linear range was 0-1200 ng/ml through using MPs and is useful for samples with extremely high AFP concentrations without dilution while avoiding the hook effect. The intra- and inter-assay precision was <3% and <5%. The present method has been successfully applied to the detection of AFP human serum with recoveries from 90 to 108%, and showed a good correlation with the commercially available AFP RIA kit.

CONCLUSIONS

This proposed assay provided apparent advantages over microplate CLEIA and RIA, and facilitated the development of high-throughput screening and automated operation systems in the clinical practice.

Diagnostic accuracy of tumor markers for hepatocellular carcinoma: a systematic review

Background and aims The role of alphafetoprotein (AFP) in the diagnosis and surveillance of hepatocellular carcinoma (HCC) is getting smaller owing to the advances in imaging modalities. The aims of this study were to assess the diagnostic accuracy of tumor markers in small HCC and to find the optimal cutoff value of each tumor marker for efficient surveillance. Methods Studies in all languages were identified by searching MEDLINE from 1982 to 2002. Studies were included when they showed sensitivity and specificity for HCCs 5 cm or smaller and recruited only patients with chronic hepatitis or liver cirrhosis as control. We assessed diagnostic odds ratios (DORs) for the evaluation of diagnostic accuracy of tumor markers and positive likelihood ratios (LRs+) to find the optimal cutoff value. DORs and LRs+ were combined according to the random effect model. The summary receiver operating characteristics (ROC) curve was also assessed. Results Seventeen articles on three tumor markers-AFP, des-gamma-carboxyprothrombin (DCP), and Lens culinaris agglutinin-reactive fraction of AFP (AFP-L3)-were enrolled after full-text evaluation. AFP was inferior to DCP and AFP-L3 in both DOR (4.50 vs. 8.16 and 10.50) and area under the ROC curve (0.647 vs. 0.688 and 0.695). Optimal cutoff values that provide the best LR+ were 200 ng/ml for AFP, 40 mAU/ml for DCP, and 15% for AFP-L3. Conclusions Diagnostic accuracy of AFP in small HCC was substantially limited. Surveillance including other tumor markers with optimal cutoff value should be conducted to confirm the efficacy of the policy.

Surveillance for hepatocellular carcinoma and early diagnosis

Good management of patients at risk for the development of hepatocellular carcinoma includes regular ultrasound surveillance, and aggressive management of lesions detected at ultrasound. Good radiology and good pathology are essential to the appropriate management of these small lesions. With good quality testing it is possible to cure the majority of HCCs using minimally invasive techniques such as radiofrequency ablation. Such an approach has the potential to convert HCC from a disease in which incidence more or less equaled mortality to one in which cure is frequently possible.

Repeated radiofrequency ablation for the distant recurrence in the liver in patients with chronic hepatitis C virus infection achieving long-term survival

Recurrence of hepatocellular carcinoma (HCC) is frequently observed in patients with hepatitis C virus (HCV) infection and the incidence of HCC recurrence is as high as 20% in these patients even after a complete curative treatment is given for the HCC nodules. We report a 57-year-old female who was referred to our hospital for the treatment of a HCC nodule of 1.8 cm diameter in S5 and having liver cirrhosis of Child-Pugh A classification with HCV infection in April 1999. The HCC nodule showed hypervascularity by computed tomography during hepatic arteriography (CTHA) and was coagulated by microwave under peritoneoscopy. Complete necrosis was confirmed by enhanced-CT scan after microwave coagulation. Thereafter, interferon alfa-2b (3MU, twice weekly) was given but HCV RNA continued to be positive. Thereafter, recurrence of HCC was noted five times in S1, S2, S6; treatment by radiofrequency ablation was given four times; and transarterial chemoembolization was carried out once. Since January 2004, peg-interferon alfa-2a (90 microm/week) has been administered, and no recurrence has been detected until August 2005. She is currently 63 years old, and quite well. Five-year-survival rate in HCC patients treated by radiofrequency ablation is 62.7% in our hospital, however, the recurrence rate is as high as 26.4% per year in the patients with chronic HCV infection. It is a point of controversy when liver transplantation should be recommended in HCC patients with liver cirrhosis of Child-Pugh A classification having chronic HCV infection because of the high incidence of recurrence.

Screening for hepatocellular carcinoma

This article reviews methodological issues around screening for hepatocellular carcinoma, and discusses selection of the at-risk group, which screening test to use, and how frequently it should be applied. Screening of patients at risk for hepatocellular carcinoma should be undertaken using ultrasonography applied at six-month intervals. Patients at risk include all those with cirrhosis, and certain non-cirrhotic patients withchronic hepatitis B. In this population, screening has been shown to reduce disease-specific mortality. Although data do not exist for other populations, screening is nonetheless advised because small cancers can be cured with appreciable frequency.

Viral Hepatitis and Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common tumor worldwide, and one of the fastest rising tumors as a result of chronic hepatitis B and C infection. The patients at risk for developing HCC are those with underlying cirrhosis secondary to viral hepatitis. External factors such as alcohol, tobacco, obesity, and diabetes increase the risk of HCC among those with chronic viral hepatitis. Surveillance of patients with cirrhosis with alpha-fetoprotein and ultrasound has been shown to reduce survival. The diagnosis of HCC is established by the presence of an arterially enhancing mass in the presence of cirrhosis. Viral hepatitis represents an opportunity for prevention of HCC.

Chronic hepatitis C and screening for hepatocellular carcinoma

It is now at least theoretically possible to prevent patients with hepatocellular carcinoma (HCC) from dying of HCC. Screening identifies small potentially curable lesions, and the diagnostic algorithm allows for efficient investigation and diagnosis. Radiofrequency ablation completely ablates more than 05% of lesions smaller than 2 cm. Second primary cancers can be dealt with in the same manner as the initial primary. If the management of HCC is so efficient and effective, liver transplantation may come to be used as a last resort, rather than the treatment of choice. This benefits patients with hepatitis C and other liver diseases because more organs become available for treatment of other liver diseases.

Prognostic factors and survival in patients with hereditary hemochromatosis and cirrhosis

OBJECTIVES

The survival of treated, noncirrhotic patients with hereditary hemochromatosis is similar to that of the general population. Less is known about the outcome of cirrhotic hereditary hemochromatosis patients. The present study evaluated the survival of patients with hereditary hemochromatosis and cirrhosis.

METHODS

From an established hereditary hemochromatosis database, all cirrhotic patients diagnosed from January 1972 to August 2004 were identified. Factors associated with survival were determined using univariate and multivariate regression. Survival differences were assessed using the Kaplan-Meier life table method.

RESULTS

Ninety-five patients were identified. Sixty patients had genetic testing, 52 patients (87%) were C282Y homozygotes. Median follow-up was 9.2 years (range 0 to 30 years). Nineteen patients (20%) developed hepatocellular carcinoma, one of whom was still living following transplantation. Cumulative survival for all patients was 88% at one year, 69% at five years and 56% at 20 years. Factors associated with death on multivariate analysis included advanced Child-Pugh score and hepatocellular carcinoma. Patients with hepatocellular carcinoma were older at the time of diagnosis of cirrhosis (mean age 61 and 54.6 years, respectively; P=0.03). The mean age at the time of diagnosis of hepatocellular carcinoma was 70 years (range 48 to 79 years). No other differences were found between the groups.

CONCLUSIONS

Patients with hereditary hemochromatosis and cirrhosis are at significant risk of developing hepatocellular carcinoma. These patients are older when diagnosed with carcinoma and may have poorer survival following transplantation than patients with other causes of liver disease. Early diagnosis and treatment of hereditary hemochromatosis by preventing the development of cirrhosis may reduce the incidence of hepatocellular carcinoma in the future.

Hepatocellular carcinoma

The number of patients who have hepatocellular carcinoma (HCC) is expected to more than double over the next 1 to 2 decades. Patients who have cirrhosis, regardless of cause, are at the highest risk for developing HCC. This article discusses surveillance of these patients for HCC by alpha-fetoprotein and ultrasound, evaluation using imaging, classification of HCC using the Barcelona staging classification, and treatment. Resection, transplantation, and percutaneous ablation are considered curative interventions and are applied to about 30% of all patients who have HCC. Currently, there is no standard therapy for advanced HCC.

Hepatitis C: a review for primary care physicians

Primary care physicians see many of the estimated 250 000 Canadians chronically infected with the hepatitis C virus (HCV). Of this number, about one-third are unaware they are infected, which constitutes a large hidden epidemic. They continue to spread HCV unknowingly and cannot benefit from advances in antiviral therapy that may clear them of the virus. Many HCV-infected people remain asymptomatic, which means it is important to assess for risk factors and test patients accordingly. The third-generation enzyme immunoassay for HCV antibodies is a sensitive and specific test, although the presence of the virus can be confirmed by polymerase chain reaction testing for HCV RNA in some circumstances. Pegylated interferon-alpha and ribavirin combination therapy clears the virus in about 45%-80% of patients, depending on viral genotype. Preventive strategies and counselling recommendations are also reviewed.

Ultrasonographic detection of hepatocellular carcinoma: correlation of preoperative ultrasonography and resected liver pathology

AIM

The aim of this study was to determine the sensitivity of ultrasonography for detecting hepatocellular carcinoma in patients who underwent surgical liver resection.

MATERIALS AND METHODS

The preoperative ultrasonography reports of 103 patients who underwent hepatic resection surgery were retrospectively reviewed. The patients had chronic liver disease with good liver function and a relatively normal liver echo-texture. The presence of a mass or masses in the resected part of the liver segments on preoperative ultrasonography was regarded as possible hepatocellular carcinoma, and these results were compared with the surgically resected hepatic lobes or segments. Accuracy for detection was assessed on a lesion-by-lesion basis, on a segment-by-segment basis, and on a patient basis.

RESULTS

One hundred and fifty-seven hepatocellular carcinomas were found in 244 hepatic segments of 103 patients. One hundred and one of 157 hepatocellular carcinomas were detected using ultrasonography in 97 patients resulting in a sensitivity of 64%. In six patients, a solitary hepatocellular carcinoma was missed in each patient, a patient sensitivity being 94%. Using ultrasonography, 87 of 100 (87%) hepatocellular carcinomas larger than 2 cm in diameter, and 14 of 57 (25%) hepatocellular carcinomas 2 cm or smaller in diameter were revealed. On the basis of segment-by-segment analysis, the sensitivity was 78% (99 of 127 segments), specificity was 97% (114 of 117 segments), accuracy was 87% (213 of 244 segments), positive predictive value was 97% (99 of 102 segments), and negative predictive value was 80% (114 of 142 segments).

CONCLUSION

In patients with chronic liver disease and good hepatic function, ultrasonography has a sensitivity of 94% in the identification of affected patients, but for individual lesions, the sensitivity is only 64%.

Survival in hepatocellular carcinoma: impact of screening and etiology of liver disease

BACKGROUND AND AIMS

As the merits of screening at-risk populations for hepatocellular carcinoma (HCC) remain unclear, we compared the clinico-pathologic features and survival of patients with cirrhosis and HCC detected by screening (Group A) to that in non-screened cases (Group B).

METHODS

We studied cirrhotics who developed HCC between 1994 and 2002. During this period, cirrhotics managed by the Gastroenterology Unit were regularly screened at 6-12 monthly intervals while those managed by other hospital units were not. Demographic data, tumor details, treatment received and survival were recorded and compared according to screening status.

RESULTS

There were 96 cases identified; 41 by screening (group A) and 55 by non-screening methods (Group B). HCC in Group A were smaller (P < 0.01), more likely unilobar (P < 0.01), at an early stage (P < 0.0005) and before vascular invasion (P < 0.005) than Group B cases. The frequency of hepatic surgery and/or local ablation was higher in Group A than Group B (P = 0.001). Overall median survival of Group A was 882 days versus 99 days in Group B (P < 0.0001). One- and 3-year probabilities of survival in Group A were 89% and 38%, versus 33% and 19% in Group B (P < 0.001). Independent predictors of survival included screening, Child-Pugh score, creatinine, tumor stage and absence of alcohol as the etiology.

CONCLUSIONS

Screening for HCC in cirrhosis identifies tumors at an earlier stage, results in a higher chance of receiving curative treatment and possibly improves patient survival. The absence of alcoholic liver disease impacts favorably on survival.

Screening for hepatocellular carcinoma

There is currently no evidence that screening patients at risk for hepatocellular carcinoma reduces mortality from the disease. Nonetheless, screening is widely practiced. Screening is a process that includes selecting patients, applying screening tests, deciding on recall policies, and subsequently proving or disproving the presence of cancer. The literature on screening for hepatocellular carcinoma is confusing at best, and does not adequately consider the many biases that result from uncontrolled and retrospective studies. Nonetheless, screening can be justified because it is likely that mortality is decreased by adequate treatment of small cancers, particularly in the era of liver transplantation. False-positive screening test results are common. Once an abnormal screening result is obtained there is little guidance from the literature as to how patients should be investigated further, nor about how to determine whether the screening test result was a false-positive. This should at minimum include short interval follow-up with CT scans and MRI's.

Systematic review of radiological imaging for hepatocellular carcinoma in cirrhotic patients

We systematically reviewed the evidence for determining the best radiological imaging for characterizing hepatocellular carcinoma (HCC) in cirrhotic patients in 997 articles between 1995 and 2001. We selected only prospective and retrospective cohorts of patients, excluding both case reports and studies without separate data on HCC. Only 29 studies, comprising 918 patients, fulfilled the inclusion criteria: 10 used the explanted liver as the reference standard of diagnosis. All except one, either found no statistically significant difference between imaging modalities or had no direct comparison of sensitivity between different modalities of imaging; 16 studies evaluated HCC among cirrhotic patients and had biopsy or imaging as the reference standard for diagnosis. However, no one imaging technique was shown to be superior. In two studies, data of a HCC subgroup was derived from the studies evaluating different kinds of focal hepatic lesions. No conclusion could be drawn because of the small sample size. One study addressed the issue of therapeutic impact. The evidence for choosing the best modality of imaging for characterizing HCC in cirrhotic patients is inadequate. Large multicentre studies with defined reference standards for diagnosis, and studies evaluating therapeutic impact are needed.