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.