Robert Wong, MD
“It is a very interesting phenomenon and there are a lot of different explanations for why this is occurring,” said Wong, an assistant clinical professor of medicine, director of research and education, Division of Gastroenterology and Hepatology at Alameda Health System, Highland Hospital. “I think one of our major hypotheses is that the current effect antiviral therapies are really suppressing disease progression. However, patients with hepatitis B and those with hepatitis B cirrhosis, still have a high risk of liver cancer. It is important to remember that these patients still need routine screening and surveillance for liver cancer.”
In an interview with Oncology Nursing News while at the 2016 Annual Meeting of the American Association for the Study of Liver Diseases, Wong discussed why certain patients are at a higher risk for hepatitis B-associated HCC, common risk factors for the disease, and the role healthcare providers need to play in improving outcomes for these patients.
Oncology Nursing News: What are you hoping clinicians take away from these findings?
Wong: The biggest takeaway is really the importance of screening and surveillance for liver cancer. Early detection is really important; it allows improved access to potentially curative therapies. Even though the current antiviral therapies are good at suppressing the virus, they do not cure hepatitis B in the majority of people. The resistance of chronic hepatitis B in these patients still carries a risk for liver cancer. There is really a need for improved screening and surveillance because we are not doing a good job right now.
In addition, at least in our study in the United States, there is a changing demographic for patients listed for liver transplant secondary to hepatitis B. We sort of expected that in the United States and in other countries because there is higher prevalence in hepatitis B for individuals from high-risk regions, including Africa and Asia.
Our studies show a shift from the early time period to the later time period that, in the most recent time period we studied, over 50% of patients with hepatitis B on the transplant list were Asian. Understanding high-risk populations, and therefore identifying who should be screened for hepatitis B, is key. These patients should always be screened for liver cancer.
Is there an understanding as to why the Asian and African populations are at a higher risk of hepatitis B and liver cancer?
There are several hypotheses that have been proposed to explain that. The first hypothesis is based on the mechanism of infection. In Asia and Africa hepatitis B is usually acquired vertically. The duration of infection is directly correlated with the risk of disease progression and HCC. That is why these patients with hepatitis B from Africa and Asia have higher risk of HCC, because they are probably infected with the virus longer.
The other very interesting hypothesis is that there are different genotypes of hepatitis B, and the genotypes found in the Asia Pacific regions have been shown to have higher risk of disease progression and higher risk of liver cancer. We don’t routinely in clinical practice check genotypes in the United States, because the different genotypes don’t generally impact treatment management decisions. But that might be something that will change in the future as we try and better identify risk factors for disease progression and also risk factors for HCC.
What are the most common risk factors for HCC?
One of the main risk factors that we know about currently is the duration of infection. The longer the person has chronic hepatitis B there is cumulative risk of developing HCC. Age is also a risk factor, but that is also a surrogate of duration of infection. The presence of advance disease, such as advanced fibrosis or cirrhosis, definitely carries a higher risk of HCC. One of the big risk factors, which was outlined in a 2008 JAMA Oncology article, is a higher hepatitis B viral load, which directly correlates with a higher risk of HCC. That is really why screening these patients, identifying who should be treated, and early treatment to suppress the virus, is so important.
Are there factors that are preventing screening from becoming more widely implemented?
There are several studies in the United States, but also in Europe and Asia, that show the missed opportunities for screening for hepatitis B. I think it is multifactorial. There are patient-related factors, patient awareness and patient education, but provider awareness and education is also important. We need to make sure that the primary physicians, or gastroenterologists, or other types of providers are aware who these high-risk populations are, who they need to screen, how to implement screening and diagnosis, and then refer them to the appropriate treatments.
Another important area where I don’t think we are doing a good job is screening for liver cancer itself. That is not just hepatitis B patients, it’s all patients who are at risk including those with cirrhosis. Hepatitis B is a very different diagnosis in that you can still develop liver cancer without cirrhosis. I think more awareness and education and helping people understand what the guidelines say about both screening for hepatitis B and liver cancer is going to be key to detection.
The most important thing to emphasize, especially for the oncology community, is that it is really important to educate those referring providers, primarily the primary care physicians, about the importance of screening their patients. Screening and early detection vastly improve curative options for these patients.
Young K, Liu, B, Bhuket T. Despite plateauing of chronic hepatitis b virus (hbv) patients listed for liver transplantation, the proportion of patients with hbv-related hepatocellular carcinoma continues to rise. Presented at the 2016 AASLD Liver Meeting; November 11-15, 2016; Boston, MA. Abstract 21.