Incidence of hepatocellular carcinoma among older Americans attributable to hepatitis C and hepatitis B: 2001 through 2013

Abstract

Background: In the United States, incidence and mortality rates of hepatocellular carcinoma (HCC) are increasing in older individuals. Chronic infection with hepatitis C virus (HCV) and hepatitis B virus (HBV) are important causes of HCC; however, the contribution of viral hepatitis to recent trends in HCC incidence among older Americans is unclear.

Methods: Data from the Surveillance, Epidemiology, and End Results-Medicare linkage (SEER-Medicare) for the years 2001 through 2013 were used to identify HCC cases among individuals aged ≥66 years and Medicare files were used to assess the HCV and HBV status of these HCC cases. Age-standardized incidence rates of HCV-attributable, HBV-attributable, and HCV/HBV-unrelated HCC were estimated overall and by age group, sex, and race/ethnicity. The authors also calculated annual percent changes (APCs) in HCC incidence.

Results: Between 2001 and 2013, a total of 15,300 HCC cases occurred in this population. Overall HCC rates increased 43% from 16.3 to 23.3 per 100,000 population (APC, 3.40% per year), whereas HCV-attributable HCC rates nearly doubled from 4.2 to 8.2 per 100,000 population (APC, 5.62% per year). HCC rates increased more slowly for HBV-attributable HCC (1.3 to 1.8 per 100,000 population; APC, 3.17% per year) and HCV/HBV-unrelated HCC (11.3 to 14.1 per 100,000 population; APC, 2.35% per year). The percentage of HCC cases with evidence of HCV infection increased from 25.7% in 2001 through 2004 to 32.3% in 2011 through 2013, whereas the percentage with HBV remained stable at 8%. In 2013, higher rates for both HCV-attributable and HBV-attributable HCC were noted among individuals aged 66 to 75 years, men, and individuals of Asian ancestry.

Conclusions: Among Americans aged ≥66 years, HCC rates increased rapidly between 2001 and 2013. Although HCV-attributable cases contributed substantially to this increase, rates of HBV-attributable and HCV/HBV-unrelated HCC also rose during this period.

Keywords: Medicare; epidemiology; hepatitis; liver cancer; trends.

Figure 1.

Prevalence of HCV and HBV infection among hepatocellular carcinoma cases in SEER-Medicare, 2001–2013 by A) sex, B) age and C) race/ethnicity. Black bars indicate the fraction of cases with HCV, gray bars indicate the fraction of cases with HBV and checkered bar indicate the fraction of cases with HCV/HBV coinfection.

Figure 2.

Age-standardized hepatocellular incidence rates in SEER-Medicare by sex, age and race/ethnicity, 2001–2013. Circles represent overall HCC rates, triangles represent HCV/HBV-unrelated HCC rates, diamonds represent HCV-attributable HCC rates and squares represent HBV-attributable HCC rates. Of note, rates of HCV-attributable and HBV-attributable HCC are not mutually exclusive.