Although hepatocellular carcinoma (HCC) in patients with cirrhosis typically arises against a background of alcohol abuse or hepatitis C virus infection, this entity was strongly associated with nonalcoholic fatty liver disease (NAFLD) and idiopathic HCC.
"While this represents a small proportion, this poses a logistical problem for HCC surveillance, given the large population with NAFLD and no real identifying features of who is going to develop HCC," Dr. Sahil Mittal said at the annual Digestive Disease Week.
Patrice Wendling/Frontline Medical News
Dr. Sahil Mittal
Despite a threefold increase in HCC in the United States over the last 3 decades and emerging evidence for NAFLD presenting in the absence of cirrhosis, this is the first study to assess the prevalence and risk factors for HCC without cirrhosis in a national sample of HCC patients, he said.
The investigators, led by Dr. Hashem B. El-Serag, section chief, gastroenterology and hepatology, Baylor College of Medicine, Houston, performed a chart review of 1,500 veterans with a confirmed diagnosis of HCC randomly selected between 2005 and 2011. Of these, cirrhosis was absent in 43 (3%), highly improbable in 151 (10%), and definite in 1,201 (80%), with the diagnosis unclear because of insufficient data in 105 (7%).
As expected, HCC patients with cirrhosis were significantly more likely than those with no or probable no cirrhosis to abuse alcohol (84% vs. 67.4% vs. 63.6%; P less than .01) and to have hepatitis C infection (72.2% vs. 42% vs. 44.4%; P less than .01), said Dr. Mittal, also with Baylor’s College of Medicine.
Hepatitis B infection was similar in all three groups (5% vs. 4.7% vs. 2%).
In contrast, NAFLD was more common in patients with no or probably no cirrhosis than in those with cirrhosis (14% vs. 20.5% vs. 5.8%; P less than .01), as was idiopathic HCC (18.6% vs. 27.8% vs. 8.2%; P less than .01), he said.
"NAFLD is associated with a significantly increased risk of HCC in the absence of cirrhosis, compared with hepatitis C or alcohol," he said.
With regard to clinical factors, sex and race did not differ between groups. However, the no and probably no cirrhosis patients were significantly older than were those with HCC accompanied by cirrhosis (65.5 years, vs. 69.7 years vs. 62.6 years) and significantly more likely to have comorbidities associated with metabolic syndrome, such as hypertension (88.4% vs. 86.8% vs. 72.6%), myocardial infarction (11.6% vs. 18.5% vs. 7.5%), and peripheral vascular disease (11.6% vs. 20% vs. 9.5%), Dr. Mittal reported. The differences among groups were statistically significant with P values of less than .01.
The investigators then performed logistic regression analysis to examine predictors of HCC without cirrhosis. After adjustment for confounders, they found NAFLD was more than threefold likely (odds ratio, 3.1) and idiopathic HCC more than twofold likely (OR, 2.8) in patients with HCC without cirrhosis, compared with patients with hepatitis C–related HCC.
This entity of HCC in the absence of cirrhosis was also associated with the metabolic syndrome–related comorbidities of hypertension (OR, 1.8) and myocardial infarction (OR, 1.8).
The findings suggest that the risk of HCC in patients with NAFLD is increased not only because of progression to cirrhosis, but possibly through other alternative noncirrhosis pathways, Dr. Mittal said in an interview. This has important implications for understanding the pathogenesis of HCC, as well as for HCC screening in NAFLD patients.
"Due to the high prevalence of NAFLD in the general population, conventional screening by ultrasonography may not be a feasible strategy, especially if one cannot rely on cirrhosis as the main predisposing lesion to HCC," he said. "Studies are needed to identify risk factors and biomarkers that can identify NAFLD patients at higher risk of developing HCC. Future research is also needed to investigate the role of chemoprevention."
Dr. Mittal reported no conflicting interests. Lead author Dr. El-Serag reported consulting fees and grant/research support from Gilead Sciences.
pwendling@frontlinemedcom.com
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