The Relationship of Chronic Viral Hepatitis, Alcoholism, and Cirrhosis to Liver Cancer
Cancer can start within the liver (primary liver cancer or hepatocellular cancer) or spread to the liver (metastatic liver cancer) from other sites, such as the colon. Cancer that starts in the liver, which I will refer to simply as liver cancer, is the fifth most common cancer in the world. In the U.S., it is among the 10 most common cancers. This cancer is more frequent among Native Americans, Asians, Pacific Islanders, and Hispanics than among Caucasians.
Liver cancer is a bad cancer. It has frequently spread beyond the liver by the time it is discovered, and only 5% of patients with liver cancer that has begun to cause symptoms survive even five years without treatment. The only hope for patients who are at risk for liver cancer is regular surveillance so that the cancers can be found early. Early cancers can be treated by surgical removal (resection), destruction of the individual tumors, or liver transplantation. Although the current techniques for surveillance are not very good at detecting early liver cancer, newer techniques are being tested and appear to be better.
The most common diseases associated with liver cancer are chronic viral hepatitis, alcoholism, and cirrhosis (scarring of the liver). Moreover, chronic viral hepatitis is common in alcoholism, and both viral hepatitis and alcoholism cause cirrhosis which usually precedes the development of cancer. Therefore, the contributions and interrelationships of alcohol abuse, viral hepatitis, and cirrhosis in the development of liver cancer are complex. Despite the complexity, it is important to try to understand the contributions of each disease so that patients at highest risk for liver cancer can be targeted for surveillance. Theoretically, they also might be targeted with treatments that prevent the development of liver cancer, when such treatments are developed.
Many studies have estimated how frequently patients with alcoholism and chronic viral hepatitis go on to develop cirrhosis and liver cancer. These studies, for the most part, have used small or selected populations to study, and there is disagreement as to whether their findings can be applied to general populations, especially in Europe and the U.S.
A scientific study published in October 2001 has added important information about the relationship of liver cancer to chronic viral hepatitis, alcoholism, and cirrhosis. This is a strong study because it used the records of Swedish health registries to identify patients for inclusion in the study. The Swedish registries contain information on the entire population of Sweden. They are large and complete registries and have been in use for many years. In fact, they have provided a wealth of information about many diseases.
An analysis of the Swedish data demonstrated that among patients with alcoholism there was slightly more than a twofold increase in the risk of liver cancer as compared with the general population. This small increase suggests that alcoholism alone is not strongly related to the development of liver cancer. On the other hand, patients who were alcoholics but also developed cirrhosis, presumably as a result of their alcoholism, had a 22-fold increase in the risk of liver cancer as compared with the general population. Clearly, the development of cirrhosis in alcoholics substantially increases the risk for liver cancer.
Patients with chronic viral hepatitis had a 34-fold greater risk for liver cancer as compared with the general population. Patients with both chronic viral hepatitis and cirrhosis, however, had a much greater increase in the development of liver cancer--118-fold. (Presumably, the cirrhosis was caused by the chronic hepatitis.) Clearly, the combination of chronic viral hepatitis and cirrhosis has a very strong association with the development of liver cancer. This association is much stronger than the association of the combination of alcoholism and cirrhosis with liver cancer. The stronger association with viral hepatitis than alcohol supports a greater role for the hepatitis viruses as compared with alcohol in promoting liver cancer.
What can we conclude from this study? First, the risk of liver cancer is markedly increased in patients with chronic viral hepatitis and cirrhosis. The risk also is increased in patients who are alcoholic and have cirrhosis, although the risk is less. Second, if we want to substantially prevent the development of liver cancer, we must identify patients before they develop cirrhosis and then prevent cirrhosis. Third, existing and newer techniques for liver cancer surveillance probably should be applied to all patients with both chronic viral hepatitis and cirrhosis and possibly to patients with both alcoholism and cirrhosis. Fourth, we need to develop better techniques for liver cancer surveillance. A satisfactory solution to the problem of liver cancer in chronic viral hepatitis and alcoholism will not be quick or easy.
Last Editorial Review: 11/1/2006
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