Pei-Ming Yang

Growth rate of asymptomatic hepatocellular carcinoma and its clinical implications.

The growth rate of 31 asymptomatic hepatocellular carcinomas (diameter less than or equal to 5 cm) discovered in 28 patients by a prospective screening program was determined by real-time ultrasonography over 36-860 days. Except for one tumor that shrank on follow-up, the doubling time ranged from 29 to 398 days, with a median of 117 days, an arithmetic mean of 136 days, and a geometric mean of 110 days. In 17 tumors with more than two measurements, the growth rate remained exponential in nine, declined in growth in seven, and showed an initial lag period in one. Doubling time correlated with initial tumor diameter but was independent of the patients age, sex, hepatitis B surface antigen status, tumor location, liver function tests, stage of liver cirrhosis, histologic type, or grade of malignancy. Although initial alpha-fetoprotein levels did not correlate well with growth rate, in 14 patients with an exponential increase of serum alpha-fetoprotein, the alpha-fetoprotein doubling time was closely related to the tumor doubling time. Based on the above data, the median detectable subclinical period of hepatocellular carcinoma was deduced to be 3.2 yr, and the suitable screening interval for its early detection in our area was 4-5 mo.

ELASTIC MODULUS MEASUREMENTS OF HUMAN LIVER AND CORRELATION WITH PATHOLOGY

Viral hepatitis causes fibrosis in the liver and may change mechanical properties of the liver. To evaluate the impact of fibrosis on elastic properties of human liver and to investigate potential benefits of ultrasonic elasticity imaging, 19 fresh human liver samples and 1 hepatic tumor (focal nodular hyperplasia) sample obtained during operations were studied. Simple 1-D estimates based on the cyclic compression-relaxation method were performed. Elastic modulus values were derived from the predetermined strain (controlled by a step motor system) and the stress values (measured by an electronic balance). Each specimen subsequently received histologic examination and a grade of liver fibrosis was scored from 0 to 5. Results show that the elastic modulus values were on the order of several hundreds to thousands of Pascals. The elastic modulus generally increased with the fibrosis grade, although some discrepancies existed at the middle grades of fibrosis (scores 1 to 3). The correlation between the fibrosis score and the elastic modulus was significant (p < 0.01) based on the statistical analysis using the Pearson correlation method. In addition, the relation between the elastic modulus and the fibrosis grade generally exhibited a quadratic trend. It was concluded that severity of fibrosis had a good correlation with stiffness of the liver. Results also indicated that the elasticity imaging of the liver may provide significant clinical values if the elastic modulus can be accurately measured.

Acute exacerbations of chronic type B hepatitis are accompanied by increased T cell responses to hepatitis B core and e antigens. Implications for hepatitis B e antigen seroconversion.

T cell proliferative responses to hepatitis B virus-encoded envelope antigen (S + preS2 + preS1), recombinant core antigen (HBcAg), and natural hepatitis B e antigen (HBeAg) were examined in 22 HBeAg-positive patients with chronic type B hepatitis and 17 healthy hepatitis B surface antigen (HBsAg) carriers. The results showed that HBeAg-positive patients had (a) higher levels of T cell responses to HBcAg/HBeAg than those of healthy HBsAg carriers (P less than 0.001 and P less than 0.01, respectively); (b) a further increase in these T cell responses during acute exacerbations (P less than 0.05 and P less than 0.05, respectively); (c) subsidence in the T cell responses to HBcAg/HBeAg after recovery from acute exacerbations and HBeAg seroconversion, whereas the responses would persist at high levels if the patients did not enter a clinical remission; and (d) low levels of T cell responses to S + preS2 + preS1 either before or after HBeAg seroconversion. The appearance of increasing T cell responses to HBcAg/HBeAg usually occurred in the early phase of acute exacerbations. These findings imply that HBcAg/HBeAg-specific T cells play an important role in the exacerbations of chronic hepatitis B and in HBeAg seroconversion. HBcAg/HBeAg-specific precursor T cell frequencies were serially studied in selected cases by limiting dilution assay. Elevation (two- to fourfold) of HBcAg/HBeAg-specific precursor T cell frequencies contributed to the increase of HBcAg/HBeAg-specific T cell proliferation during acute exacerbations.

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.

Early detection of hepatocellular carcinoma by real-time ultrasonography. A prospective study

For early detection of hepatocellular carcinoma (HCC), real‐time ultrasonography (US) was performed prospectively in 528 patients, including 236 with cirrhosis, 81 with chronic hepatitis, 168 asymptomatic hepatitis B surface antigen carriers, and 43 with a family history of HCC. Simultaneous measurement of serum alpha‐fetoprotein (AFP) level was also done. In addition, 233 patients had regular controls at 3‐ to 6‐month intervals, with an average follow‐up period of 1.4 years. On initial screening, a total of 17 patients were found to have HCC: 13 in the cirrhotic group, 3 in the HCC family group, and 1 in the asymptomatic carriers. Of these HCCs, 7 were smaller than 3 cm, 6 were between 3 to 5 cm, and 4 were larger than 5 cm. In patients with tumors smaller than 5 cm, the AFP levels were normal in 46.2%, between 20 to 400 ng/ml in another 46.2%, and only 7.6% were over 400 ng/ml. On follow‐up, another seven patients, all in the cirrhotic group, were found to have HCCs varying from 1.6 to 4.7 cm; three of them had normal serum AFP level. The authors conclude that real‐time US is more sensitive than AFP assay in early detection of HCC, and the high‐risk subjects should receive this procedure at regular intervals.

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.