Hepatocellular carcinoma (HCC) is increasing in incidence and has a very high fatality rate. Cirrhosis due to chronic hepatitis B or hepatitis C is the leading risk factor for HCC. Global epidemiology of HCC is determined by prevalence of dominant viral hepatitis and the age it is acquired in the underlying population. Upcoming risk factors include obesity, diabetes and related non-alcoholic fatty liver disease. This review discusses the latest trends of HCC globally and in the United States. It also provides an evidence-based commentary on the risk factors and lists some preventive measures to reduce the incidence of HCC.

Background & Aims Hepatocellular carcinoma (HCC) can develop in individuals without cirrhosis. We investigated risk factors for development of HCC in the absence of cirrhosis in a US population. Methods We identified a national cohort of 1500 patients with verified HCC during 2005–2010 in the US Veterans Administration (VA), and reviewed their full VA medical records for evidence of cirrhosis and risk factors for HCC. Patients without cirrhosis were assigned to categories of level 1 evidence for no cirrhosis (very high probability) or level 2 evidence for no cirrhosis (high probability), based on findings from histologic analyses, laboratory test results, markers of fibrosis from non-invasive tests, and imaging features. Results A total of 43 (2.9%) of the 1500 patients with HCC had level 1 evidence for no cirrhosis and 151 (10.1%) had level 2 evidence for no cirrhosis; the remaining 1203 patients (80.1%) had confirmed cirrhosis. Compared to patients with HCC in presence of cirrhosis, greater proportions of patients with HCC without evidence of cirrhosis had metabolic syndrome, non-alcoholic fatty liver disease (NAFLD), or no identifiable risk factors. Patients with HCC without evidence of cirrhosis were less likely to have abused alcohol or have HCV infection than patients with cirrhosis. Patients with HCC and NAFLD (unadjusted odds ratio, 5.4; 95% confidence interval, 3.4–8.5) or metabolic syndrome (unadjusted odds ratio, 5.0; 95% confidence interval, 3.1–7.8) had more than a 5-fold risk of having HCC in the absence of cirrhosis, compared to patients with HCV-related HCC. Conclusions Approximately 13% of patients with HCC in the VA system do not appear to have cirrhosis. NAFLD and metabolic syndrome are the main risk factors HCC in the absence of cirrhosis.

Background & Aims Non-alcoholic fatty liver disease (NAFLD) is a risk factor for hepatocellular carcinoma (HCC). However, no systemic studies from the United States have examined temporal trends, HCC surveillance practices, and outcomes of NAFLD-related HCC. Methods We identified a national cohort of 1500 patients who developed HCC from 2005 through 2010 from Veterans Administration (VA) hospitals. We reviewed patients’ full VA medical records; NAFLD was diagnosed based on histologic evidence for, or the presence of, metabolic syndrome in the absence of hepatitis C virus (HCV) infection, hepatitis B, or alcoholic liver disease. We compared annual prevalence values for the main risk factors (NAFLD, alcohol abuse, HCV), as well HCC surveillance and outcomes, among HCC patients. Results NAFLD was the underlying risk factor for HCC in 120 patients (8.0%); the annual proportion of NAFLD-related HCC remained relatively stable (7.5%–12.0%). In contrast, the proportion of HCC cases associated with HCV increased from 61.0% in 2005 (95% confidence interval, 53.1%–68.9%) to 74.9% in 2010 (95% confidence interval, 69.0%–80.7%). The proportion of HCC cases associated with only alcohol abuse decreased from 21.9% in 2005 to 15.7% in 2010, and the annual proportion of HCC cases associated with hepatitis B remained relatively stable (1.4%–3.5%). A significantly lower proportion of patients with NAFLD-related HCC had cirrhosis (58.3%) compared to patients with alcohol- or HCV-related HCC (72.4% and 85.6%, respectively; P<.05). A significantly higher percentage of patients with NAFLD-related HCC did not receive HCC surveillance in the 3 years before their HCC diagnosis, compared to patients with alcohol- or HCV-associated HCC. A lower proportion of patients with NAFLD-related HCC received HCC-specific treatment (61.5%) than of patients with HCV-related HCC (77.5%; P<.01). However, 1-year survival did not differ among patients with HCC related to different risk factors. Conclusions NAFLD is the third most common risk factor for HCC in the VA. The proportion of NAFLD-related HCC was relatively stable from 2005 through 2010. Although patients with NAFLD-related HCC receive less HCC surveillance and treatment, a similar proportion survive for 1 year, compared to patients with alcohol- or HCV-related HCC.

These data suggest that the large enhancement of P2XR expression and function may contribute to the maintenance of visceral hypersensitivity, thus identifying a specific neurobiological target for the treatment of chronic visceral hyperalgesia.