About 13% of U.S. veterans with hepatocellular carcinoma had no evidence of preexisting cirrhosis, according to a report published in the January issue of Clinical Gastroenterology and Hepatology.
“The main risk factors for this entity were nonalcoholic fatty liver disease [NAFLD] or metabolic syndrome” – not hepatitis C virus infection [HCV], HBV [hepatitis B virus] infection, or alcohol abuse, said Dr. Sahil Mittal of the Michael E. DeBakey Veterans Affairs Medical Center and Baylor College of Medicine in Houston. Screening all patients with NAFLD for hepatocellular carcinoma [HCC] is impractical, so studies should seek “actionable risk factors” or biomarkers that reliably identify NAFLD patients who are at particular risk of HCC, wrote Dr. Mittal and his coinvestigators.
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Researchers have debated whether chronic HCV infection or alcohol abuse can lead to HCC in the absence of cirrhosis, while at least one study has shown that NAFLD can predispose patients to this disease entity (Arch Pathol Lab Med. 2008;132:1761-6).
But few studies have systematically examined risk factors for HCC without cirrhosis in the general population, the investigators said. Therefore, they randomly selected 1,500 patients from the U.S. Veterans Affairs system who were diagnosed with HCC between 2005 and 2010 on the basis of histopathology or established imaging criteria (Hepatology 2005;42:1208-36).
They reviewed complete medical records for these patients, and classified those who did not have cirrhosis according to the quality of supporting histology, laboratory, and imaging data (Clin Gastroenterol Hepatol. 2015. doi: 0.1016/j.cgh.2015.07.019).
In all, 3% of the cohort had level 1 (“highest-quality”) evidence for not having cirrhosis, while another 10% had level 2 evidence for no cirrhosis, the investigators said. “Compared with HCC in the presence of cirrhosis, these patients were more likely to have metabolic syndrome or NAFLD or no identifiable risk factor, and less likely to have alcohol abuse or HCV infection,” they added. Only two-thirds of NAFLD patients with HCC had cirrhosis, compared with 91% of patients with chronic HCV infection, 92% of HCV-infected patients, and 88% of patients with an alcohol use disorder. Notably, the odds of HCC in the absence of cirrhosis were more than five times higher when patients had NAFLD (odds ratio [OR], 5.4; 95% confidence interval [CI], 3.4-8.5) or metabolic syndrome (OR, 5.0; 95% CI, 3.1-7.8) compared with HCV infection.
Patients with cirrhosis often go unscreened for HCC even though they are at greatest risk of this cancer. Therefore, trying to screen all patients with NAFLD for HCC would be “logistically impractical,” particularly when the absolute risk of HCC in noncirrhotic patients is unknown and no one has examined the best ways to screen this population, the investigators said. Instead, clinicians could prioritize screening and treating NAFLD patients for diabetes mellitus and obesity, both of which are associated with HCC. “There is evidence to suggest that metformin reduces the risk of HCC among diabetics,” they added. “Studies of these and other risk factors of HCC among NAFLD patients with and without cirrhosis are needed.”
Most patients in the study were male, potentially limiting the generalizability of the findings, the researchers noted.
The National Cancer Institute, the Houston Veterans Affairs Health Services Research and Development Center of Excellence, the Michael E. DeBakey Veterans Affairs Medical Center, and the Dan Duncan Cancer Center funded the study. The researchers had no disclosures.