OBJECTIVETo investigate the role of absent ductular reaction (DR) at hepatocellular-stromal boundaries in early stage hepatocellular carcinoma (HCC) with cirrhosis in patients with chronic hepatitis B.

METHODSCytokeratin (CK)7 and CK19 expression was detected by the SP immunohistochemistry method in 112 hepatic nodules taken from 20 cases of early HCC, 26 cases of HCC with nodules more than 3 cm, 20 cases of high-grade dysplastic nodule (HGDN), 26 cases of low-grade dysplastic nodule (LGDN), and 20 cases of cirrhosis (CIR). DR/CK7 and DR/CK19 were assessed separately on a semi-quantitative scale and statistically analyzed.

RESULTSThe mean age of the patients in the study was 53.71 years-old, and the study population consisted of 73 males and 39 females. The follow-up time ranged from 3 to 90 months. Positive CK7 and CK19 staining was detected in the cytoplasm of DR-positive hepatobiliary cells, interlobular bile duct, and a portion of hepatic cells. All of the DR/CK7- and DR/CK19-positive cells were localized around the non-invasive nodules. Specimens with focal or diffuse DR/CK7- and DR/CK19-loss had more robust stromal invasion. Specimens from early HCC cases showed greater DR/CK19 loss than specimens from HGDN cases, LGDN cases and CIR cases (all P less than 0.01). DR/CK7 loss of early HCC was less than HCC with nodules more than 3 cm (P less than 0.05), and more than LGDN cases and CIR cases (both P less than 0.01).The area under the receiver operating characteristic curve of DR/CK7 was very similar to that of DR/CK19 (P more than 0.05). Pearson's correlation analysis indicated that DR/CK7 and DR/CK19 were positively correlated with tumor-free time (P less than 0.01) and negatively correlated with early recurrence time as well as death rate (both P less than 0.01). Furthermore, cases showing DR/CK7 or DR/CK19 loss had lower overall survival rate and tumor-free survival rate (P less than 0.01) and higher early recurrence rate (P less than 0.01).

CONCLUSIONDR/CK7 and DR/CK19 immunostaining may help to distinguish non-invasive HGDNs from both minimally-invasive and overtly-invasive HCCs by identifying small foci of invasion and predicting increased risk of invasiveness.