t lthough known to be a common cause of cancer worldwide, hepatocellular carcinoma (HCC) has ong been considered a rare tumor in the United States.1 ndeed, in a recent review of the epidemiology of digesive diseases, HCC was said to rank 22nd among the auses of cancer mortality in the United States.2 The resentations made during this workshop show that hese beliefs are no longer correct. Liver cancer is the ost rapidly increasing cause of cancer in the United tates, accounting for at least 14,000 deaths yearly and anking eighth as a cause of cancer mortality in men.3,4 t is important to note that HCC is one of the few cancers hat is increasing in frequency and in mortality in the nited States. The rapid increases in rates of HCC in the United tates and the developed world correlate with similar ncreases in the prevalence of chronic infection with epatitis C virus (HCV) in these same countries—inreases in frequency that occurred in the 1960s and 970s.3,5–9 These features are compatible with what is nown about the natural history of HCV infection and ts complications. Chronicity occurs in approximately 5% of people acutely infected with HCV, and, of the atients who develop chronic hepatitis C, approximately ne third develop progressive fibrosis and cirrhosis.10 nce cirrhosis is present, HCC develops in 1% to 4% of atients yearly.11 Thus, the incubation period between he onset of HCV infection and the appearance of HCC s 2 to 4 decades. At present, cross-sectional surveys ndicate that more than half of current cases of HCC in he United States, Europe, and Japan are attributable to CV infection and that most patients have cirrhois.6,12,13 The increase in incidence of HCC in the developed orld has not been matched by improvements in survival or this cancer. HCC remains a highly malignant tumor, ith average survival rates after the onset of symptoms of ess than 1 year.14 The problems with treatment of HCC re many, but the major difficulty is that most patients ith HCC present when the disease is at an advanced tage, by which time the tumor is no longer amenable to esection or ablation. Furthermore, almost all patients ave cirrhosis, so chemotherapies or major resections are ot well tolerated. Clearly, the most practical approach o better management of HCC is prevention and, barring hat, early detection combined with local resection or blation. Yet even with regular surveillance and early etection followed by resection or ablation, recurrence is ommon. The conditions that led to the initial HCC cirrhosis, HCV, or hepatitis B virus [HBV] infection) re usually still present after resection, and appearance of e novo or recurrent cancer is common. For these reasons, iver transplantation has been increasingly used as an pproach to management and potential cure of HCC.15,16 nfortunately, there is an increasing crisis in the shortge of livers for transplantation, and allocation of more nd more livers to patients with HCC may overwhelm he distribution system. All of these factors bespeak a need for action to proote research that might reverse these trends. The 3 ost appropriate means to accomplish this are prevenion, early detection, and better therapies. Also imporant for any approach to decreasing the burden of HCC s better information on the frequency of this cancer and ts clinical presentations, risk factors, and underlying auses.