The natural history of hepatocellular carcinoma in Western countries

Hepatocellular carcinoma (HCC) often has a long-lasting subclinical incubation period during which it may grow as a solitary mass. This does not mean that, in some patients, the tumor may be found as more than one nodule when it is first detected. The so-called expanding, encapsulated type of tumor seems to prevail among Oriental, Italian and French patients, rather than the more aggressive, spreading form of tumor. However, many patients with apparently single encapsulated HCC nodes may have ancillary tumors detectable only with highly sensitive imaging techniques or during surgery. There are important variations in the growth rate of this tumor, even in a single patient with multiple nodes. These differences in the growth patterns of HCC have made a clear understanding of the natural history of this tumor and prediction of patient survival difficulty. Thus, survival times are better correlated with the severity of liver impairment than with the number or size of tumors. Hepatic failure and gastrointestinal bleeding are the leading causes of death in both Oriental and Caucasian patients, accordingly. There are still many aspects of the natural history of HCC to be investigated, including whether or not all HCCs originate from one clone of transformed liver cells or more, as well as identifying which tumor and/or patient characteristics may predict individual tumor growth rates.