Evaluation of hepatitis B and C virus infections as risk factors for hepatocellular carcinoma in Sindh, Pakistan
Date of Award
Master of Science in Epidemiology & Biostatistics (MSc Epidemiology & Biostats)
Community Health Sciences
Hepatocellular carcinoma (HCC) is one of the most common cancers in the world with a relatively high prevalence in regions of Asia and sub-Saharan Africa where the annual incidence of HCC is up to 500-cases/100,000 population. HCC is the cause of about one million deaths in the world annually. There are contrasting reports on the interactive role of hepatitis b virus (HBV) and hepatitis C virus (HCV) in the development of HCC. The characterization of these interactions is important in estimating risks for HCC associated with joint exposures to both IIBV and HCV infections and in understanding the pathogenesis of HCC. The purpose of the current study is to examine the possible independent and interactive effect of HBV and HCV infection on HCC in Karachi, Pakistan. It is the first case control study to evaluate HBV and HCV infections as risk factors for HCC in this setting. We enrolled 57 cases of HCC and 149 controls from three tertiary care hospitals of Karachi during July 2001 and May 2002. Data was collected via a structured questionnaire and blood samples were obtained for hepatitis B surface antigen (HBsAg) and anti-HCV antibody assessment. In our study 47 cases (82.5%) were biopsy proven. The mean age of cases was 57 years, while among controls a mean age of 52 years was observed. The final logistic regression model included age, sex, cirrhosis, and HBsAg x anti-HCV. The odds of having cirrhosis among the cases were 38 times .the odds of having cirrhosis in the control group after adjusting for the effect of other variables in the model (OR:38.1; CI: 12.9 - 112.4). After adjusting for the effect of other variables in the model and taking both HBsAg and anti-HCV negative as a reference category, cases as compared to controls were more likely to be positive for HBsAg alone (adjusted OR : 10.1; CI: 2.1- 48.5), positive for anti-HCV alone (adjusted OR : 4.0; CI: 1.3 - 12.9), or positive for both HBsAg and anti- HCV (adjusted OR : 24.7; CI: 2.2 - 276.6), showing significant interaction between HBsAg and anti-HCV. Smoking, consumption of alcohol, family history of liver disease and family history of cancer did not show a statistically significant association with HCC. In conclusion this study suggested a significant interaction between HBV and HCV infections in their relationship with HCC in Pakistan. This is an evidence for the health authorities to take appropriate steps for designing effective intervention strategies to prevent exposure to HBV and HCV in our setting to decrease the occurrence of new cases of HCC in Sindh, Pakistan
Hamza, H. B. (2002). Evaluation of hepatitis B and C virus infections as risk factors for hepatocellular carcinoma in Sindh, Pakistan (Unpublished doctoral thesis). Aga Khan University, Karachi, Pakistan.