Guan-Tarn Huang

Aflatoxin exposure and risk of hepatocellular carcinoma in Taiwan

To investigate the carcinogenic effect of environmental aflatoxin exposure, 56 cases of hepatocellular carcinoma (HCC) diagnosed between 1991 and 1995 were identified and individually matched by age, sex, residence and date of recruitment to 220 healthy controls from the same large cohort in Taiwan. Blood samples were analyzed for hepatitis B and C viral markers and for aflatoxin‐albumin adducts; urine was tested for aflatoxin metabolites. We obtained information about socio‐demographic characteristics, habitual alcohol drinking, cigarette smoking and diet in a structured interview. Hepatitis B virus surface antigen (HBsAg) carriers had a significantly increased risk for HCC. After adjustment for HBsAg serostatus, the matched odds ratio (ORm) was significantly elevated for subjects with high levels of urinary aflatoxin metabolites. When stratified into tertiles, a dose‐response relationship with HCC was observed. The ORm for detectable aflatoxin‐albumin adducts was not significant after adjustment for HBsAg serostatus. HBsAg‐seropositive subjects with high aflatoxin exposure had a higher risk than subjects with high aflatoxin exposure only or HBsAg seropositivity only. In male HBsAg‐seropositive subjects, adjusted ORs were 2.8 (95% confidence interval [Cl] = 0.9–9.1) for detectable compared with non‐detectable aflatoxin‐albumin adducts and 5.5 (Cl = 1.3–23.4) for high compared with low urinary aflatoxin metabolite levels. Our results suggest that environmental aflatoxin exposure may enhance the hepatic carcinogenic potential of hepatitis B virus. A large‐scale study will be needed to evaluate the effect of aflatoxin exposure on HBsAg non‐carriers.

Estimation of Seroprevalence of Hepatitis B Virus and Hepatitis C Virus in Taiwan from a Large-scale Survey of Free Hepatitis Screening Participants

BACKGROUND/PURPOSE Taiwan is a hyperendemic area of liver diseases. Hepatitis B virus (HBV) and hepatitis C virus (HCV) are the two major etiologies of liver diseases in Taiwan. This study investigated the seroprevalence of HBV and HCV in Taiwan. METHODS Since 1996, a series of outreach community-based screening programs for liver diseases have been available to the general population aged > or = 18 years. Blood samples were obtained from the subjects and sent for hepatitis B surface antigen (HBsAg) and antibody to HCV (anti-HCV) tests. RESULTS The prevalence of HBsAg(+) was 17.3% (27,210/157,720), while the prevalence of anti-HCV(+) was 4.4% (6904/157,720). Geographic variation in HBV and HCV seroprevalence was found, with the highest anti-HCV positive rate in Miaoli County, Chiayi County, Chiayi City, and Yunlin County, and the highest HBsAg positive rate in Keelung City and Yilan City. The HBsAg positive rate progressively decreased after the age of 50 years, while the anti-HCV positive rate progressively increased after the age of 20 years. The estimated total number of HBsAg carriers in the general population > 20 years old is 3,067,307, while the estimated number of anti-HCV positive patients is 423,283. CONCLUSION This study estimated a 17.3% seroprevalence of HBV and a 4.4% seroprevalence of HCV in Taiwan. Significant geographic variations in the seroprevalence of HBV and HCV were found. These data suggest the importance of modifying programs for the prevention and treatment of chronic viral hepatitis in Taiwan to reflect its varying prevalence and epidemiology.

Percutaneous Ethanol Injection Versus Surgical Resection for the Treatment of Small Hepatocellular Carcinoma: A Prospective Study

Objective:To compare disease recurrence and survival among patients with small hepatocellular carcinoma after surgical resection or percutaneous ethanol injection therapy, 2 treatments that have not been evaluated with a prospective study. Methods:A total of 76 patients were randomly assigned to 2 groups based on treatment; all had one or 2 tumors with diameter ≤3 cm, with hepatitis without cirrhosis or Child class A or B cirrhosis without evident ascites or bleeding tendency. Results:Follow-up ranged from 12 to 59 months. Among percutaneous injection patients, 18 had recurrence 1 to 37 months after treatment (true recurrence, 11; original safety margin inadequate, 3; limitation of imaging technology to detect tiny tumors, 4). Three injection therapy patients died of cancer 25, 37, and 57 months after treatment. For the surgical resection group, 15 had recurrence 2 to 54 months after treatment (true recurrence, 12; limitation of imaging, 2; neck metastasis, 1). Five resection patients died of cancer at 11, 20, 23, 26, and 52 months, respectively. By Cox regression model and Kaplan-Meier survival analysis, there is no statistical significance for recurrence and survival between treatment groups. However, tumor size larger than 2 cm and alpha-fetoprotein over 200 ng/mL correlated with higher recurrence rate, and Child class B liver cirrhosis correlated with shorter survival. Conclusions:Percutaneous ethanol injection therapy appears to be as safe and effective as resection, and both treatments can be considered first-line options for small hepatocellular carcinoma.

Hepatitis C and B viruses in hepatitis B Surface antigen-negative hepatocellular carcinoma

The relative role of hepatitis C virus and hepatitis B virus in hepatitis B surface antigen-negative hepatocellular carcinoma was evaluated by polymerase chain reaction in 31 patients from Taiwan. Twenty-one were positive for antibody to hepatitis C virus (group 1) and 10 were negative (group 2). Of the group 1 patients, hepatitis C viral RNA was detected in the serum by polymerase chain reaction in 16 and in the liver tissue in 17, whereas hepatitis B viral DNA was found in the liver tissue in only 4, and none were found in the serum. In group 2 patients, hepatitis C viral RNA was detected in the serum of 1 and in the liver tissue of another. In contrast, hepatitis B viral DNA was found in the serum of 4 patients and in the liver tissues of 5. It was concluded that hepatitis C virus plays an important role in hepatocarcinogenesis in hepatitis B surface antigen-negative patients in Taiwan, especially in those who had antibody to hepatitis C virus; in those without antibody to hepatitis C virus, hepatitis B virus might still be associated with the development of hepatocellular carcinoma in a significant proportion of such patients.

Ultrasound screening and risk factors for death from hepatocellular carcinoma in a high risk group in Taiwan.

Although previous studies have demonstrated the ability of ultrasonography (US) screening to detect small asymptomatic hepatocellular carcinoma (HCC), the efficacy of US screening in reducing deaths from HCC still remained unresolved. A 2‐stage screening program was designed to identify a high risk group in 7 townships in Taiwan by 6 markers (of risk for HCC) and repeated US screening was further applied to those with at least 1 positive result for the 6 markers, with a range of 3‐ to 6‐month inter‐screening intervals to those with liver cirrhosis or other chronic liver diseases and an annual screening regime for the remaining subjects with normal findings according to US. The 4,843 subjects in this cohort were followed up for an average of 7 years. We compared 4,385 attenders with 458 non‐attenders, in conjunction with baseline assessment for self‐selection bias. In addition, we assessed baseline variables with respect to their effects on risk of incidence of and mortality from HCC and on risk of incidence of liver cirrhosis. The difference in mortality between attenders and non‐attenders was then re‐estimated adjusting for significant predictors of cirrhosis, HCC incidence and HCC death as a further guard against baseline differences between attenders and non‐attenders in risk profiles. Results of US screening for this high risk group found the mortality was lower by 24% (95% CI: −52 to 62%) in the attenders compared to the non‐attenders. After adjustment for sensitivity, the mean sojourn time (MST) were 1.57 (95% CI: 0.94–4.68) for subjects with liver cirrhosis and 2.66 (95% CI: 1.68–6.37) years for non‐cirrhotic patient. Significant increases in risk of HCC incidence were associated with increasing age, male gender, hepatitis B surface antigen positive (HbsAg), hepatitis C antibody positive (Anti‐HCV), high levels of alanine transaminase (ALT) and alpha‐fetoprotein (AFP) and a family history of HCC. Significantly increased risks of liver cirrhosis were associated with predictors of cirrhosis were increasing age, HbsAg, high levels of ALT and of AFP. Significant or borderline significant increases in risk of HCC death were associated with increasing age, male gender, HbsAg, high levels of AST and AFP. Adjusted for the significant variables, the mortality was lower by 41% (95% CI: −20 to 71%, p = 0.1446) in the attenders compared to the non‐attenders. The present study provides suggestive evidence on the efficacy of US screening in a selective high risk group in an endemic area of hepatitis B. A randomized controlled trial would yield definitive evidence. Within the protocol of such a trial, a shorter interscreening interval for patients with liver cirrhosis is suggested.

Ultrasound-guided cutting biopsy for the diagnosis of hepatocellular carcinoma — a study based on 420 patients

BACKGROUND/AIMS To evaluate ultrasound-guided cutting biopsy for hepatocellular carcinoma, we report findings from 10 years of experience. METHODS We performed 455 ultrasound-guided cutting biopsies of hepatic tumors in 420 patients with hepatocellular carcinoma from 1981 to 1990. RESULTS Liver tissues were adequately sampled for a histological diagnosis of hepatocellular carcinoma in the initial biopsy in 391 sessions. The remaining 64 were proved to have hepatocellular carcinoma after subsequent studies. Ultrasound-guided biopsy changed the initial diagnosis in 9 of the 420 patients: three had been diagnosed with liver abscess, and six with metastatic liver tumors. Complications of the biopsy were rare: the tumor had spread to the chest wall in nine, and internal bleeding was noted in five patients. There was no mortality and no other sequelae. CONCLUSIONS Ultrasound-guided biopsy of hepatic tumors is important in the diagnosis of liver cancer, but this technique should be applied only when the image diagnosis and results of fine needle biopsy are equivocal to minimize possible complications. For patients with small HCCs, who are candidates for surgical resection of hepatocellular carcinoma or liver transplantation, it should not be considered as a first-step invasive procedure.

Clonal origin of recurrent hepatocellular carcinomas.

Recurrence of hepatocellular carcinoma after treatment is frequent. To study the clonal origin of the recurrent tumors, we examined five pairs of hepatocellular carcinomas resected from individual hepatitis B surface antigen carriers. Using integrated hepatitis B virus DNA as a marker, tumor clonality was determined by Southern blot analysis. In 2 cases the second tumor contained the same integrated viral DNA as the first one. In the other 3 cases, the clonality of the second cancer differed. We conclude that recurrent hepatocellular carcinomas originate from the first tumor in some cases but represent de novo neoplasms in others.

Multipotential mesenchymal stem cells from femoral bone marrow near the site of osteonecrosis.

Stem cell‐based therapies for degenerative disorders and injuries are promising in the new era. Multipotential mesenchymal stem cells (MSCs) from bone marrow (BM) are on the leading edge because they are easy to expand in culture while maintaining their multilineage potential. In vitro assessment of the chondrogenic and osteogenic potentials of cultured MSCs has been established, and the BM used in those experiments was exclusively from healthy donors via iliac crest aspiration. It is unknown whether human marrow obtained from femurs also contains these multipotential MSCs. We collected marrow from proximal femurs of two patients undergoing total hip replacement surgery for femoral head osteonecrosis and isolated and culture expanded MSCs to about 20 population doublings. These cells were homogeneously positive for β1‐integrin. When pelleted into aggregates and cultured in a medium containing transforming growth factor‐β3 for 14 days, the cells began to express mRNA for aggrecan and collagen type II and to deposit immunoreactive collagen type II and sulfated proteoglycans in the matrix, hallmarks of chondrogenic differentiation. These MSCs could also be differentiated into osteocytic lineage in vitro, as shown by increased expression of alkaline phosphatase activity and deposition of mineral content onto culture plates. These results indicate that femoral BM obtained during hip surgeries also contained multipotential MSCs. These data imply that direct replacement therapy using MSCs from in situ marrow may be possible in the future and that an MSC bank may be established by using marrow from this approach, bypassing the necessity for iliac marrow aspiration from healthy donors.

ED overcrowding in Taiwan: facts and strategies.

The objective of this study was to quantity the extent of emergency department (ED) overcrowding in Taiwan and to identify possible solutions. The ED log was reviewed for all patients who presented to the National Taiwan University Hospitals ED from January 16, 1996 through February 15, 1996. Charts from patients held longer than 72 hours were reviewed. Among 5,810 patients, 213 (3.6%) were held in the ED for more than 72 hours (7.1 patients per day). In 149 (70.0%) of them, admission was indicated but delayed (42 because more than one subspecialty were involved, 57 because of unavailability of bed, and 50 because of the disparity in admission priority between the emergency physicians and house staffs). Eighteen (8.4%) patients did not meet admission criteria (13 could have been treated in outpatient clinics, 3 needed placement in nursing homes, 2 because of personal problems). The others (22%) recovered while waiting. Significant overcrowding exists in EDs in Taiwan. Four solutions are proposed: (1) creation of a holding unit; (2) flexible ward assignment; (3) pre-established rules for admission priority-setting; and (4) active interfacility transfer. Only through these efforts can EDs in Taiwan guarantee an optimal level of care in the face of a growing patient demand.

Loss of heterozygosity at chromosome 13q in hepatocellular carcinoma: identification of three independent regions

Loss of heterozygosity (LOH) on chromosome 13q is one of the most common genetic alterations in hepatocellular carcinoma (HCC) and might be involved in liver cancer development through inactivation of tumour suppressor genes. In order to narrow down the region of 13q loss, we examined the pattern of loss of heterozygosity (LOH) in tumours from 88 HCC patients, using 18 microsatellite markers on 13q. Thirty-eight of the 88 tumours (43%) showed LOH for at least one marker. Of these, two tumours (5%) showed 13q whole arm allelic loss, while the remaining 36 tumours (95%) had partial allelic loss. The LOH pattern defined by the 36 tumours suggested the existence of at least three different smallest common deleted regions which might be involved in the carcinogenesis of HCC. The first, the most centromeric in the 13q12.3 is, close to the BRCA2 gene, defined by D13S171; the second, the most telomeric region in the 13q31-32 band, is defined by D13S154 and D13S157; the third, the intermediate region at 13q14.3, which is near the RB gene, is defined by loci D13S268. The rate of LOH at 13q31-32 was significantly higher in Hepatitis B-surface antigen (HBsAg)-positive patients than HBsAg-negative HCC patients, pointing to a candidate gene related to the development of HBsAg-positive HCCs.