Opportunities for Prevention of HCC
The opportunities for prevention include measures aimed at primary prevention and secondary prevention. Primary prevention refers to preventing HCC in patients at risk who have never had HCC, whereas secondary prevention refers to preventing a second tumor or recurrence of tumor in patients who have already had HCC.
Primary Prevention: At this time, the most effective way to prevent development of HCC is to assure universal vaccination against hepatitis B virus. Highly effective and safe vaccines are available, and studies, chiefly from the Far East, leave no doubt that universal vaccination against HBV decreases the development of HBV infection, chronic hepatitis, and chronic HBV carrier states. As already described, these are major risk factors for development of hepatocellular carcinoma later in life.
The second major virus to prevent is hepatitis C viral infection. Currently, there is no vaccine available for hepatitis C infection, and there is none on the horizon. Until an effective vaccine becomes available, it will be difficult to prevent the spread of hepatitis C viral infection. We will have to continue to screen all blood and blood products, to educate intravenous drug users not to reuse syringes and needles, and try to make sure that any drug-taking paraphernalia is new and sterile. Syringe and needle exchange programs would probably help, but, in the USA at least, they face probably insurmountable political and social obstacles. The other major way to halt the spread of hepatitis C viral infection is to assure that people practice safe sex, particularly those with multiple sex partners.
Other factors important for primary prevention of HCC include decreasing or stopping the use of alcohol or tobacco, particularly in high risk patient groups, and reducing exposures to aflatoxins.
Seen less commonly, but of great importance for those with the diseases, are the inherited metabolic diseases associated with high risk development of hepatocellular carcinoma. These include type 1 hereditary tyrosinemia, certain glycogen storage diseases, the acute porphyrias, etc. Some patients, such as those with type 1 hereditary tyrosinemia or glycogen storage disease, should undergo prophylactic liver transplantation, because the risk of HCC is so high.
Secondary Prevention: Recent evidence from Europe suggests that the routine use of 131I-labeled lipiodol, given after resectional or other therapy for HCC, decreases the risk of development of recurrent tumors. Larger studies with more patients are urgently needed to confirm these exciting preliminary results. Other therapies that have also been reported in small trials to be of benefit in secondary prevention of HCC include the use of oltipraz or certain kinds of retinoids. In view of the increasing incidence of HCC, not only in the USA, but throughout the world, additional trials on primary and secondary prevention are going to be of increasing importance in the foreseeable future.
