Analysis of cost-effectiveness of different strategies for hepatocellular carcinoma screening in hepatitis B virus carriers

Screening for Hepatocellular Carcinoma in Patients with Hepatitis B

Chronic hepatitis B (CHB) infection is a significant risk factor for developing hepatocellular carcinoma (HCC). As HCC is associated with significant morbidity and mortality, screening patients with CHB at a high risk for HCC is recommended in an attempt to improve these outcomes. However, the screening recommendations on who to screen and how often are not uniform. Identifying patients at the highest risk of HCC would allow for the best use of health resources. In this review, we evaluate the literature on screening patients with CHB for HCC, strategies for optimizing adherence to screening, and potential risk stratification tools to identify patients with CHB at a high risk of developing HCC.

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.

Status of, and strategies for improving, adherence to HCC screening and surveillance

Hepatocellular carcinoma (HCC) represents the second leading cause of cancer deaths worldwide and the main cause of death in patients with cirrhosis. Secondary prevention of HCC can be accomplished through the serial application of screening tests (ultrasound with or without alpha-fetoprotein) to detect the presence of subclinical lesions amenable to potentially curative treatment, such as surgery and ablation. The efficacy of HCC screening is accepted by hepatologists in terms of decline in cancer-specific mortality, but its translation into clinical practice is less than ideal. The effectiveness of HCC screening is hampered by several factors: failure to identify at-risk patients, failure to access care and failure to detect HCC. For each of these steps, possible improvements are discussed in order to face the changing etiology of cirrhosis and expand the screening of at-risk populations by including selected nonalcoholic fatty liver disease patients.

Prediction of fatty liver disease using machine learning algorithms

BACKGROUND AND OBJECTIVE

Fatty liver disease (FLD) is a common clinical complication; it is associated with high morbidity and mortality. However, an early prediction of FLD patients provides an opportunity to make an appropriate strategy for prevention, early diagnosis and treatment. We aimed to develop a machine learning model to predict FLD that could assist physicians in classifying high-risk patients and make a novel diagnosis, prevent and manage FLD.

METHODS

We included all patients who had an initial fatty liver screening at the New Taipei City Hospital between 1st and 31st December 2009. Classification models such as random forest (RF), Naïve Bayes (NB), artificial neural networks (ANN), and logistic regression (LR) were developed to predict FLD. The area under the receiver operating characteristic curve (ROC) was used to evaluate performances among the four models.

RESULTS

A total of 577 patients were included in this study; of those 377 patients had fatty liver. The area under the receiver operating characteristic (AUROC) of RF, NB, ANN, and LR with 10 fold-cross validation was 0.925, 0.888, 0.895, and 0.854 respectively. Additionally, The accuracy of RF, NB, ANN, and LR 87.48, 82.65, 81.85, and 76.96%.

CONCLUSION

In this study, we developed and compared the four classification models to predict fatty liver disease accurately. However, the random forest model showed higher performance than other classification models. Implementation of a random forest model in the clinical setting could help physicians to stratify fatty liver patients for primary prevention, surveillance, early treatment, and management.

Hepatocellular carcinoma

Liver cancer is the second leading cause of cancer-related deaths globally and has an incidence of approximately 850,000 new cases per year. Hepatocellular carcinoma (HCC) represents approximately 90% of all cases of primary liver cancer. The main risk factors for developing HCC are well known and include hepatitis B and C virus infection, alcohol intake and ingestion of the fungal metabolite aflatoxin B1. Additional risk factors such as non-alcoholic steatohepatitis are also emerging. Advances in the understanding of the molecular pathogenesis of HCC have led to identification of critical driver mutations; however, the most prevalent of these are not yet druggable targets. The molecular classification of HCC is not established, and the Barcelona Clinic Liver Cancer staging classification is the main clinical algorithm for the stratification of patients according to prognosis and treatment allocation. Surveillance programmes enable the detection of early-stage tumours that are amenable to curative therapies - resection, liver transplantation or local ablation. At more developed stages, only chemoembolization (for intermediate HCC) and sorafenib (for advanced HCC) have shown survival benefits. There are major unmet needs in HCC management that might be addressed through the discovery of new therapies and their combinations for use in the adjuvant setting and for intermediate- and advanced-stage disease. Moreover, biomarkers for therapy stratification, patient-tailored strategies targeting driver mutations and/or activating signalling cascades, and validated measurements of quality of life are needed. Recent failures in the testing of systemic drugs for intermediate and advanced stages have indicated a need to refine trial designs and to define novel approaches.

Surveillance for hepatocellular carcinoma

When hepatocellular carcinoma presents with symptoms cure is seldom possible and death usually follows within months. However, it is possible to detect HCC early, at which stage it is curable. This requires a surveillance program. The components of such a program include: identification of the at risk population, provision of appropriate surveillance tests, and an appropriate method of determining whether the abnormalities found on screening are cancer or not. Surveillance for liver cancer meets all these criteria. Unfortunately high quality evidence showing benefit of liver cancer surveillance is lacking, but lesser quality evidence is plentiful, including several cost efficacy analyses that all show that surveillance does decrease mortality. Therefore all the continental liver disease societies and all national liver disease societies have recommended that surveillance should be undertaken.

Cost-effectiveness of liver cancer screening in adults at high risk for liver cancer in the republic of Korea

PURPOSE

This study was conducted in order to determine the most cost-effective strategy, in terms of interval and age range, forliver cancer screening in the high-risk population of Korea.

MATERIALS AND METHODS

A stochastic modelwas used to simulate the cost-effectiveness ofliver cancer screening by combined ultrasonography and alpha-fetoprotein testing when varying both screening intervals and age ranges. The effectiveness of these screening strategies in the high-risk population was defined as the probability of detecting preclinical liver cancer, and costwas based on the direct cost ofthe screening and confirmative tests. Optimal cost-effectiveness was determined using the incremental cost-effectiveness ratio.

RESULTS

Among the 36 alternative strategies, one-year or two-year interval screening for men aged between 50 and 80 years, six-month or one-year interval screening for men aged between 40 and 80 years, and six-month interval screening for men aged between 30 and 80 years were identified as non-dominated strategies. For women, identified non-dominated strategies were: one-year interval screening between age 50 and 65 years, one-year or six-month interval screening between age 50 and 80 years, six-month interval screening between age 40 and 80 years, and six-month interval screening between age 30 and 80 years.

CONCLUSION

In Korea, a one-year screening interval for men aged 50 to 80 years would be marginally cost-effective. Further studies should be conducted in order to evaluate effectiveness of liver cancer screening, and compare the cost effectiveness of different liver cancer screening programs with a final outcome indicator such as qualityadjusted life-years or disability-adjusted life-years.

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.

Surveillance and diagnosis of hepatocellular carcinoma in patients with cirrhosis

Early identification of hepatocellular carcinoma (HCC) is more frequent because of surveillance programs for HCC worldwide. The optimal strategy of surveillance in cirrhosis is a current topical issue. In terms of diagnosis, recent advances in non-invasive imaging technology, including various techniques of harmonic ultrasound, new ultrasound contrast agents, multi-slice helical computed tomography and rapid high quality magnetic resonance, have all improved the accuracy of diagnosis. Consequently the role of liver biopsy in diagnosis of HCC has declined. The imaging diagnosis relies on the hallmark of arterial hypervascularity with portal venous washout. However, with recent advances in genomics and proteomics a great number of potential serum and tissue markers have been identified and are being developed as new candidate markers for both diagnosis and prognosis of hepatocellular carcinoma, and may increase the need for liver biopsy.

Application of surveillance programs for hepatocellular carcinoma in the Asia-Pacific Region

Hepatocellular carcinoma (HCC) is a potential target for cancer surveillance (or screening) as it occurs in well-defined, at-risk populations and curative therapy is possible only for small tumors. Surveillance has been recommended by regional liver societies and is practiced widely, but its benefits are not clearly established. Hepatic ultrasonography with or without alpha fetoprotein (AFP) performed every 6 months is the preferred program. Surveillance of HCC has been well shown to detect small tumors for curative treatment, which may be translated to improved patient survival. However, most studies are limited by lead-time bias, length bias for early diagnosis of small HCC, different tumor growth rates and poor compliance with surveillance. Cost-effectiveness of surveillance programs depends on the rate of small HCC detected 'accidentally' (routine imaging) in a comparator group, annual incidence of HCC with various etiologies, patient age and the availability of liver transplantation. The incremental cost-effectiveness for 6-monthly AFP and ultrasound has been estimated from approximately $US 26,000-74,000/quality adjusted life years (QALY). All cirrhotic patients are therefore recommended for HCC surveillance unless the disease is too advanced for any curative treatment. As chronic hepatitis B can develop into HCC without going through liver cirrhosis, high-risk non-cirrhotic chronic hepatitis B patients are also recommended for HCC surveillance. In conclusion, HCC surveillance could be effective at reducing disease-specific mortality with acceptable cost-effectiveness among selected patient groups, provided it is a well-organized program.

Hepatocellular cancer: a guide for the internist

Hepatocellular cancer is the third leading cause of cancer-related deaths worldwide. Its incidence has increased dramatically in the United States because of the spread of hepatitis C virus infection and is expected to increase for the next 2 decades. Hepatitis B virus, hepatitis C virus, and chronic heavy alcohol use leading to cirrhosis of the liver remain the most important causes. The diagnosis of hepatocellular cancer rests on a combination of radiologic, serologic, and histopathologic criteria. Liver transplantation is the only definitive treatment. Resection of the tumor and other percutaneous therapies are more commonly used in practice, because most hepatocellular cancers are detected at an advanced stage. Patients who are at high risk for the development of hepatocellular cancer should be screened with an ultrasound of the liver every 6 months. The prognosis is dependent on both the underlying liver function and the stage at which the tumor is diagnosed. The aim of this review is to familiarize internists in screening, diagnosis, and referral of patients with hepatocellular cancer in an appropriate and timely fashion.

Diagnostic and prognostic role of alpha-fetoprotein in hepatocellular carcinoma: both or neither?

BACKGROUND

The clinical usefulness of alpha-fetoprotein (AFP) in hepatocellular carcinoma (HCC) management is debatable.

OBJECTIVES

To assess, in a large multi-centric survey, diagnostic and prognostic reliability of AFP, predictive factors, and any correlation with the tumor immunophenotype.

METHODS

A total of 1,158 patients with HCC were analyzed with reference to serum AFP levels at diagnosis. We evaluated: HCC grading, histotype, and size; Okuda, tumor-nodes-metastases (TNM), and Child-Pugh scores; liver function, symptoms, presence of metastases or portal thrombosis, etiology, survival, and treatment. In 66 patients with histological diagnosis, the pathologists evaluated p53 overexpression, MIB 1 labeling index, BCL-2 positive cells (index of apoptosis), and CD44 (adhesion molecule) positivity.

RESULTS

Patients were divided into three AFP groups: normal (<20 ng/mL) [46%], elevated (21-400 ng/mL) [36%], and diagnostic (>400 ng/mL) [18%]. Statistical correlations were significant for: weight loss (p= 0.0056), pain (p= 0.0025), Child-Pugh score (p= 0.001), tumor size, Okuda's and TNM stages, metastases, thrombosis, type of treatment (all p < 0.0001), and female sex (p < 0.004). AFP correlated with survival overall, in patients untreated, transplanted, or undergoing locoregional treatments; but not in those surgically treated. In the discriminant analysis, the related variables were size, female sex, Child-Pugh score, TNM staging (steps 1-4). When using the receiver operating characteristic curve, the prognostic reliability of AFP was limited with area under the curve of 0.59. Finally, patients with low expression of BCL2 had high AFP levels (p < 0.05). AFP positively correlated with Edmonson score (p < 0.0001).

CONCLUSION

The evaluation of this large series of HCC patients allowed us to: confirm the low sensitivity (54%) of AFP in the diagnosis of HCC and its prognostic value, albeit limited, being tumor size, female sex (intriguingly enough), Child-Pugh score, and TNM staging independent predictors.

How to predict HCC development in patients with chronic B viral liver disease?

Hepatocellular carcinoma (HCC) is one of the major malignant diseases in Asia. Although no randomized controlled studies have demonstrated decreased mortalities, screening for HCC has become an accepted procedure in the high-risk population. Since the incidence of HCC is strikingly different according to geographical distribution of risk factors, especially chronic hepatitis B virus (HBV) infection, a surveillance strategy in high endemic areas should be established according to national conditions. Chronic necro-inflammation by persistent HBV infection per se can progress to cirrhosis and the occurrence of HCC. As in other chronic liver diseases, the more risk factors the chronic B viral patients have, the higher occurrence of HCC was shown. Based on the risk factors of 4,339 Korean patients, the individual prediction model (IPM) was made by the calculation of relative weighs of risk factors and a self-exploited screening program for HCC was established accordingly. US screening at 6-month intervals was beneficial for the early detection of HCC, especially in the high-risk group, and prolonged survival. The usefulness of a tailored screening program with IPM for HCC was prospectively confirmed. The effective screening system for diagnosis of HCC limited to patients with chronic hepatitis B might be necessitated in high endemic area.

Alpha-fetoprotein and ultrasonography screening for hepatocellular carcinoma

Although there is no definitive evidence that hepatocellular carcinoma (HCC) screening in high-risk groups improves survival, many physicians screen high-risk populations with various strategies. alpha-fetoprotein (AFP) and liver ultrasonography (US) are the most widely used tools. AFP sensitivity and specificity depend on the cut-off value chosen. In cirrhotic patients, using a cut-off level of 20 ng/mL, sensitivity is only around 60% and positive predictive value ranges from 9% to 50%, depending on HCC prevalence. Sensitivity and specificity are much higher (94.1% and 99.9%, respectively) in hepatitis B carriers, but positive predictive value is only 5%. The performance of US as a screening tool varies widely depending on the experience of the examiner and the technology used. Recent studies generally indicate a 60% sensitivity or higher, a specificity greater than 90%, and a positive predictive value of 70%. The cost effectiveness of screening strategies using AFP, US, or both have been estimated retrospectively or using decision models. In general, HCC screening using both AFP and US appears to be of borderline cost effectiveness or not cost effective at all. Based on the estimated HCC doubling time, the recommended screening interval is 6 months, although a 1-year interval seems as effective. Currently, HCC screening with AFP only is not recommended except when US is either not available or of poor quality. US seems more efficient as a screening tool. Pathology assessment of liver explants in living-donor transplantation programs will provide more precise and reliable information regarding the value of AFP and US as HCC screening tools.

Cost-effectiveness of screening for hepatocellular carcinoma in patients with cirrhosis due to chronic hepatitis C

BACKGROUND

Screening for hepatocellular carcinoma in cirrhotic patients using abdominal ultrasonography and alpha-foetoprotein levels is widely practiced.

AIM

To evaluate its cost-effectiveness using a Markov decision model.

METHODS

Several screening strategies with abdominal ultrasonography or computerized tomography and serum alpha-foetoprotein at 6-12-month intervals in 40-year-old patients with chronic hepatitis C and compensated cirrhosis were simulated from a societal perspective, resulting in discounted costs per quality-adjusted life-year saved. Extensive sensitivity analysis was performed.

RESULTS

For the least efficacious strategy, annual alpha-foetoprotein/ultrasonography, the incremental cost-effectiveness ratio (vs. no screening) was $23 043/quality-adjusted life-year. Biannual alpha-foetoprotein/annual ultrasonography, the most commonly used strategy in the United States, was more efficacious, with a cost-effectiveness ratio of $33 083/quality-adjusted life-year vs. annual alpha-foetoprotein/ultrasonography. The most efficacious strategy, biannual alpha-foetoprotein/ultrasonography, resulted in a cost-effectiveness ratio of $73 789/quality-adjusted life-year vs. biannual alpha-foetoprotein/annual ultrasonography. Biannual alpha-foetoprotein/annual computerized tomography screening resulted in a cost-effectiveness ratio of $51 750/quality-adjusted life-year vs. biannual alpha-foetoprotein/annual ultrasonography screening.

CONCLUSIONS

Screening for hepatocellular carcinoma is as cost-effective as other accepted screening protocols. Of the strategies evaluated, biannual alpha-foetoprotein/annual ultrasonography gives the most quality-adjusted life-year gain while still maintaining a cost-effectiveness ratio <$50 000/quality-adjusted life-year. Biannual alpha-foetoprotein/annual computerized tomography screening may be cost-effective.

Screening for hepatocellular carcinoma: survival benefit and cost-effectiveness

BACKGROUND

The prognosis for patients with hepatocellular carcinoma (HCC) is poor by the time they present with symptoms. This review examines the usefulness of screening programs from the perspectives of survival benefit and of cost-effectiveness.

MATERIALS AND METHODS

Articles were searched through Medline for screening, HCC, treatment and cost-effectiveness.

RESULTS

Both ultrasonography and alpha-fetoprotein testing have a low sensitivity for detecting HCC, although a combination of the two investigations can increase sensitivity. They remain the main screening methods because they are convenient, non-invasive and easily assessable. Though earlier studies fail to show improvement in patient management and survival by screening, more recent studies demonstrate that screening can increase the chance of curative treatment and, more importantly, improve survival even after the adjustment of lead-time bias. This is probably due to the improvement in medical treatment and technology. The cost per tumor detected for a region is inversely proportional to the tumor incidence of that region.

CONCLUSIONS

In countries with a low prevalence of HCC, screening for HCC is not cost-effective. But in countries with a high prevalence of HCC, especially when screening is directed at older patients with a high risk of HCC, screening programs for HCC become much more cost-effective.

Surveillance for hepatocellular carcinoma in patients with chronic viral hepatitis in the United States of America

BACKGROUND

Measurement of serum alpha-fetoprotein (AFP) and abdominal ultrasound (US) examination are used for the early detection of hepatocellular carcinoma (HCC) in chronic liver disease patients. However, the accuracy and usefulness of these tests in a clinical setting in the United States of America have not been clarified.

METHODS

We conducted a 7-year prospective surveillance study by using both AFP and US to detect HCC in 602 patients with chronic viral hepatitis. Our main goal was to determine the optimal test for detection of early HCC. We also assessed the clinical outcome of HCC patients identified during this time period.

RESULTS

Thirty-one cases of HCC were detected. Serum AFP levels were elevated in 74% of HCC patients, but was also high in 10% of patients who did not develop HCC. The positive predictive value for AFP to detect HCC was only 12% or less for all AFP cut-off values, and the maximum joint sensitivity and specificity as determined by receiver operator characteristic analysis was approximately 65 and 90%, respectively. Abdominal US identified all 31 cases of HCC. The positive predictive value for US examinations to detect HCC was 78%, while the sensitivity and specificity was 100 and 98%, respectively. After detection of HCC, 24 (77%) patients died within a mean of 16.7 +/- 19.4 months.

CONCLUSIONS

Our study indicates that US examination was more accurate in detecting HCC. Because of its poor predictive value and low sensitivity, serum AFP should not be used as the only test for screening and surveillance for HCC.

Screening for cancer in viral hepatitis

Early diagnosis of HCC is possible because certain risk factors for this tumor are known and because sensitive and relatively inexpensive diagnostic tools are available. Early diagnosis of HCC is also possible because of the long phase of asymptomatic tumor growth and the tumor's tendency to grow as a solitary mass in many patients. In two consensus development conferences held in Anchorage, Alaska and in Milan, Italy, chronic carriers of HBsAg, patients with cirrhosis, patients with rare metabolic liver diseases, and individuals with family histories of HCC were identified as patients at high risk for HCC and therefore as candidates for periodic screening. At the Anchorage conference, it was recommended that healthy carriers have at least yearly determinations of serum AFP and that carriers with additional risk factors (e.g., cirrhosis) be screened every 6 months by abdominal US scans and determination of serum AFP levels. No specific recommendations were released for HBsAg-negative patients with chronic liver disease. At the Milan conference, it was recommend that patients with cirrhosis or with certain congenital metabolic conditions known to be at risk for HCC should be screened by AFP determination and US scan twice a year. It was also recommended that HBsAg carriers older than 35 years or with family histories of HCC should be screened for HCC by determinations of serum AFP levels and aminotransferase levels once a year.

Screening for hepatocellular carcinoma

Screening for hepatocellular carcinoma has become widely practised in the management of patients with end-stage liver disease. However, the theoretical basis for this practice is largely lacking. Issues such as the selection of the target population and the correct method of confirming positive screening tests have yet to be resolved. Complicating the assessment of screening strategies is the poor literature on comparing different forms of therapy. Nonrandomized, uncontrolled studies that do not account for lead-time bias make it frequently impossible to know whether an applied treatment has really improved survival. Despite these difficulties, screening is reality, and strategies have to be devised to efficiently screen patients, find small tumours and apply effective treatments. Some practical strategies are discussed.

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

OBJECTIVE

The purposes of this study were to determine the incidence of hepatocellular carcinoma (HCC) in patients with chronic hepatitis or cirrhosis and to assess the cost and benefit of sonographic screening for HCC.

MATERIALS AND METHODS

We reviewed 647 sonograms of 232 patients obtained over an 8-year period. One hundred fifty-two patients had at least two sonograms. One hundred fifty-four men and 78 women with a mean age of 51 years were included. Most patients (n = 207) had biopsy-proven cirrhosis. Ethnicity, age, gender, type of liver disease, and alpha-fetoprotein levels were analyzed to determine factors associated with HCC detection. The costs of sonography and other tests were calculated using the Australian government Medicare benefits schedule.

RESULTS

Thirty-one patients (13%) had elevated alpha-fetoprotein levels. Liver masses were found in 25 (11%) patients. Six (2.6%) patients had HCC on biopsy (n = 3) or other tests. All cases of HCC were inoperable because of tumor multicentricity or metastases (n = 2) or both, or because of the relatively large size or poor physical condition of the patient (n = 4) or both. The only variable associated with detection of HCC was alcohol-related liver disease (p = .01). Of the six patients with HCC, one had an elevated alpha-fetoprotein level. The yearly incidence of HCC was 1.4%. Other masses shown by sonography included regenerating nodules (n = 5), hemangiomas (n = 5), focal fat sparing (n = 4), metastases (n = 2), and other lesions (n = 3). No patient underwent surgical resection, which precluded calculation of a survival benefit. The cost of our screening program was $8472 (United States dollars) per HCC. CONCLUSION. Sonographic screening is superior to alpha-fetoprotein assay for detection of HCC, but in this study, screening did not decrease mortality.

Ultrasound characterization by stable statistical patterns

It is shown that automated characterization of ultrasound images can be achieved effectively if the images are confined to single internal organs. The ultrasound image of a particular organ gives statistical textures of its structures, which are consistent with stable patterns. Analysis of these patterns leads to the construction, from a few statistical parameters, of a fast and effective algorithm to characterize these ultrasound images. A small training set is adequate. A similar approach may be used to detect tumour sites from liver ultrasonograms. The algorithms are implemented on an IBM-compatible personal computer for future incorporation into existing ultrasound machines.

Prospective study of early detection for primary liver cancer

PURPOSE

To determine whether repeated screening can lead to early detection of primary liver cancer (PLC) and in turn to an improved clinical result.

METHODS

In this randomized controlled study, Shanghai urban residents aged 35-55 years and with serum evidence of HBV infection or chronic liver disease were eligible for recruitment. Using cluster sampling, these subjects were allocated into two groups-the screening group and the control group: there were 8109 subjects in the screening group and 9711 in the control group. Subjects in the screening group were tested with serum AFP and real-time ultrasound every 6 months. One to four rounds of screening were completed. Liver cancer was treated according to stage at diagnosis.

RESULTS

All subjects enrolled were followed up and classed at the end-point as alive without liver cancer, alive with liver cancer, dead from liver cancer, or dead from another cause. The mean follow-up was 1.2 years; total follow-up was 12,038 person-years in the screening group and 9,573 person-years in the control group. We detected 38 patients with PLC in the screening group and 18 patients with PLC in the control group. In the patients in the screening group 76.8% of patients were at a subclinical stage, and 70.6% of them underwent resection, the 1- and 2-year survival rates being 88.1% and 77.5%, respectively. However, in the control group, none of the patients was at a subclinical stage when diagnosed, none of them underwent resection, and none of them survived over 1 year. The lead time was estimated at 0.45 years. The cost of detecting PLC at an early stage was RMB 12,600 (US$1,500).

CONCLUSION

The study proved that screening the high-risk population for PLC with a serum AFP test and real-time ultrasound examination can detect patients in the early stages, increase the resection rate and prolong the survival time. It is therefore recommended that screening for PLC be advocated in any high-risk area.

Hepatitis B

Hepatitis B remains a major public health problem around the world. The discovery of the hepatitis C virus has diverted interest from hepatitis B to this new virus and the epidemic associated with it, but hepatitis B remains a significant pathogen for millions of people worldwide. The World Health Organization has suggested that universal vaccination of children against hepatitis B should be implemented in an attempt to reduce the enormous morbidity and mortality associated with infection of this virus group. The review seeks to identify all the newer discoveries relating to hepatitis B that have been made in the past decade. Reference is made to the appearance of hepatitis B mutants which are able to infect patients previously infected with the wild strain of the virus. The implications of mutants on vaccination programmes is raised, as are issues relating to treatment of hepatitis B infection.

Secondary prevention of hepatocellular carcinoma

Two decades have gone by since the earlier trials of alpha-fetoprotein (AFP) screening for hepatocellular carcinoma (HCC) were conducted in Africa and China. It is accepted that early detection, diagnosis and treatment of HCC remains an important target to be achieved before a breakthrough appears on the primary prevention of HCC. In the present study, screening investigations were performed in a high risk population of HCC, defined as persons who had hepatitis, blood transfusions, a family history of HCC, and were hepatitis B virus carriers. Ultrasonography combined with AFP serosurvey was accepted as an effective screening procedure to detect small HCC. Early diagnosis of HCC was not difficult if tumour markers and medical imaging were combined. Early resection has been proven to prolong survival of patients with small HCC. Repeated intralesional ethanol injection is an alternative treatment to surgery, while transcatheter arterial embolization is a less effective alternative. Re-resection of subclinical recurrence after curative resection has proven of merit in prolonging survival even further. Resection of small HCC remains an important approach in getting long-term HCC survival and to improving 5-year survival rates. It is more effective than treatment of large HCC. Studies on the secondary prevention of HCC have stimulated research into tumour markers, the natural history and cellular origin of HCC and oncogenes. However, the issue of 'cost-effectiveness' remains to be evaluated.

Sensitivity analysis in economic evaluation: a review of published studies

A structured methodological review of journal articles published in 1992 was undertaken to determine whether recently published economic evaluation studies deal systematically and comprehensively with uncertainty. Ninety three journal articles were identified from a range of searches including a computerised search of the MEDLINE CD-Rom database. Articles were reviewed to determine how they had handled uncertainty in: a) data sources; b) generalisability; c) extrapolation; and d) analytic method. Articles were subsequently assessed to determine how they had represented this uncertainty in terms of the overall results of their analysis. Finally, studies were rated on the basis of their overall performance with respect to dealing systematically and comprehensively with uncertainty. Despite the numerous books and articles devoted to the appropriate methods to be employed by analysts conducting economic evaluation, 22 (24%) studies failed to consider uncertainty at all and 35 (38%) studies employed sensitivity analysis in a manner judged as inadequate. In all, 36 (39%) studies were judged to have given at least an adequate account of uncertainty with 13 (14%) of those judged to have provided a good account of uncertainty. Such disappointing results may reflect a general lack of detail in much of the methods literature concerning how sensitivity analysis should be applied and how results should be presented. Journal editors and readers of economic evaluation articles should acquaint themselves with the methods for handling uncertainty in order that they can critically evaluate the extent to which authors have allowed for uncertainties inherent in their analysis.