Hepatocellular cancer (HCC) can be prevented through vaccination against hepatitis B. This has been recently shown in a Taiwanese study that reported a significant decline in the incidence of HCC in children 10 years after the introduction of a nation-wide hepatitis B vaccination programme. After chronic hepatitis B, alcoholic liver cirrhosis is the next most common aetiology of HCC locally. Keeping consumption of alcohol to within safe limits can also prevent this. Thus the two main underlying causes of HCC in Singapore can be curtailed to a great extent, translating indirectly into prevention of HCC.

If prevention has failed, the next best thing to do would be to screen individuals at risk of developing HCC. Early/pre-clinical HCC bears better cure-rate after surgical treatment. Such early disease seldom poses symptoms, hence ‘screening’ or detecting occult/asymptomatic HCC is of utmost importance. In our department’s experience, HCCs that are diagnosed via screening are significantly more operable, and hence curable, than compared to HCCs that presented symptomatically.

B Who should be screened? Basically any individual with cirrhosis, regardless of aetiology, are candidates for HCC screening. Risk of developing HCC is further accentuated by male sex, older age and a positive family history of HCC. The cornerstone of screening is imaging, usually by ultrasound, as it is radiation-free. Imaging rather than blood tests (LFT, AFP) is the preferred screening tool because patients with early HCC can have perfectly normal LFT and a serum AFP level well within the normal range. The ideal interval for screening is not easily established. However, as the median doubling rate of HCCs in our Asian region is about 117 days, screening at 6-monthly intervals seems reasonable. However screening with AFP & US has pitfalls & limitations (Read in this issue - Innovationsin screening)

Vaccination against hepatitis B has already been alluded to as a successful preventive measure against HCC. The hepatitis B vaccine is one of the most successful vaccines ever made because of its very high efficacy rate and excellent safety profile. A complete course consists of three doses. The final seroconversion rate is more than 95%. Common causes of non-response include improper storage of vaccine leading to degradation of the product, incorrect administration and immunosuppressed patients. The underlying problem, if apparent, should be remedied before administering an empirical fourth dose to non-responders. The other option for non-responders will be to use the new, more immunogenic pre-S hepatitis B vaccine.

Thus HCC can be prevented to some extent. Screening should be done for all individuals at risk as it can result in a higher cure rate. Universal hepatitis B vaccination should be practised because of its far-reaching beneficial effects on the story of HCC.

Dr Tan Chee Kiat

Senior Consultant

Department of Gastroenterology Singapore General Hospital