Features of fibrosis regression abound in "non-cirrhotic" patients with resected hepatocellular carcinoma.

Cirrhosis is a major risk factor for developing hepatocellular carcinoma (HCC). However, many surgically resected HCCs are presumably non-cirrhotic. The dynamic nature of chronic liver disease leads to periods of hepatic repair and fibrosis regression. We hypothesize that most resected HCCs, including those from non-cirrhotic patients, exhibit features of fibrosis regression in their background liver, suggesting previously more advanced liver disease. We reviewed the histology of 37 HCC resections performed between 2005-2020, including 30 from non-cirrhotic patients. The non-neoplastic liver was evaluated for features of liver disease and of the hepatic repair complex (HRC). CD34 immunohistochemistry was performed as a marker of sinusoidal capillarization. CD34 staining was evaluated manually and also by a digital image classifier algorithm. Overall, 28 cases (76%) had a high number of fibrosis regression and hepatic repair features (≥4 out of 8 features). Amongst the 30 non-cirrhotic patients, 21 (70%) showed a high number of repair features. Relative CD34 expression was increased in cases with a high number (≥4) of HRC features versus a low number (≤3) of features (p = 0.019). High HRC cases were more likely to exhibit nodular circumferential CD34 staining (p = 0.019). Our findings suggest that most resected HCC from non-cirrhotic patients display features of fibrosis regression in their background liver. Thus many, if not most, HCC patients who are "non-cirrhotic" may in fact have regressed cirrhosis. This finding reinforces that patients with regressed cirrhosis continue to be at high risk for HCC.