The impact of immigration on the increasing incidence of hepatocellular carcinoma in the United States.

Abstract

To assess if the rising incidence of hepatocellular carcinoma in the United States can be accounted for by immigration and an ageing population, or is a true increase among the USA-born residents. Design--A retrospective chart review. Setting--Urban, multiethnic hospital and specialty clinics in a large indigent health system in Houston, Texas. Subjects--Approximately 23,000 admissions and 143,000 out-patient clinic visits each year from 1992 through 2001 were assessed. A total of 494 patient records were selected and reviewed because of suspicion of hepatocellular carcinoma. Analysis- Hepatocellular carcinoma was confirmed by histopathology, alpha-fetoprotein level >400 ng/mL, and suggestive imaging studies. The age-adjusted incidence was determined and causative factors were identified. About 111 cases of confirmed hepatocellular carcinoma were found. The age-adjusted incidence rose from 3.44 per 100,000 hospital admissions during 1992-1996 (95% confidence interval: 2.86-4.02) to 5.19 during 1997-2001 (95% confidence interval: 4.41-5.97). The proportion of patients of non-USA place of birth decreased between 1992-1996 and 1997-2001 (46-24%, respectively, P = 0.03). Fifty-two per cent and 68% were hepatitis C virus-positive respectively; 37% and 34% were hepatitis B surface antigen-positive respectively; 46% and 59% had a history of alcohol abuse; and 22% and 11% had no identifiable risk factors. The incidence of hepatocellular carcinoma within the greater Houston area has increased during the past decade, rising by 51% from 1992-1996 to 1997-2001. This increase is not from immigration or population ageing but represents a true rise among the native born population. Hepatitis C and alcoholic cirrhosis are associated with a majority of cases, particularly in the latter half of the decade.