Cancer burden in the year 2000. The global picture

Clinical observations have suggested that the number of cases of hepatocellular carcinoma has increased in the United States. We analyzed data from the Surveillance, Epidemiology, and End Results (SEER) data base to determine the age-adjusted incidence of hepatocellular carcinoma from 1976 to 1995, data from the U.S. vital-statistics data base to determine age-adjusted mortality rates from 1981 to 1995, and data from the Department of Veterans Affairs to determine age-adjusted rates of hospitalization for the disease from 1983 to 1997. The incidence of histologically proved hepatocellular carcinoma increased from 1.4 per 100,000 population (95 percent confidence interval, 1.3 to 1.4) for the period from 1976 to 1980 to 2.4 per 100,000 (95 percent confidence interval, 2.3 to 2.4) for the period from 1991 to 1995. Among black men, the incidence was 6.1 per 100,000 for the period from 1991 to 1995, and among white men, it was 2.8 per 100,000. There was a 41 percent increase in the mortality rate from primary liver cancer and a 46 percent increase in the proportion of hospitalizations attributable to this disease during the periods studied. The incidence increased significantly among younger persons (40 to 60 years old) during the period from 1991 to 1995 as compared with earlier periods. An increase in the number of cases of hepatocellular carcinoma has occurred in the United States over the past two decades. The age-specific incidence of this cancer has progressively shifted toward younger people.

Incidence rates for esophageal adenocarcinoma previously were reported to be increasing rapidly, especially among white males. Rates for gastric cardia adenocarcinoma also were observed to be rising, although less rapidly. In this article, the authors update the incidence trends through 1994 and further consider the trends by age group. Surveillance, Epidemiology, and End Results (SEER) program data were used to calculate age-adjusted incidence rates for esophageal carcinoma by histologic type and gastric adenocarcinoma by anatomic subsite. Among white males, the incidence of adenocarcinoma of the esophagus rose > 350% since the mid-1970s, surpassing squamous cell carcinoma around 1990. Rates also rose among black males, but remained at much lower levels. To a lesser extent, there were continuing increases in gastric cardia adenocarcinoma among white and black males, which nearly equaled the rates for noncardia tumors of the stomach in white men. The upward trend for both tumors was much greater among older than younger men. Although the incidence also rose among females, rates remained much lower than among males. Previously reported increases of esophageal adenocarcinoma are continuing, most notably among white males. Cigarette smoking may contribute to the trend through an early stage carcinogenic effect, along with obesity, which may increase intraabdominal pressure and predispose to gastroesophageal reflux disease. Further research into esophageal and gastric cardia adenocarcinoma is needed to clarify the risk factors and mechanisms responsible for the upward trends as well as the racial and gender disparities in incidence.