Argyrophilic nucleolar organizer regions (AgNOR) of resected intrahepatic cholangiocellular carcinomas

Abstract

Background/aims: Thxe argyrophilic nucleolar organized resion (AgNOR) is loop DNA encoded for rRNA production on the nucleoli, which controls cell proliferation and protein synthesis (1,2). Based on numerous studies, it has been suggested that the AgNOR number correlates with both cellular kinetics and the malignant grade of the tumor.

Materials and methods: The argyrophilic nucleolar organized regions (AgNOR) of 14 operated cases with intrahepatic cholangiocellular carcinoma (IHCCC) were examined.

Results: The number of AgNOR per nucleus (the AgNOR score) was found to be related to both the level of carcinoembryonic antigen (CEA) (r = 0.63, P = 0.016) and the size of the tumor (r = 0.62, P = 0.017). Regarding the age, sex, the presence or absence of lymph node metastasis, the grade of TNM classification, and the main location of the tumor, no statistical significance was recognized. On the other hand, both histological difference and differentiation were observed to remarkably reflect the AgNOR score (P = 0.03). The cancer-free survival and survival rate showed no relationship to the AgNOR score, but patients with an AgNOR number lower than 2.0 showed a poorer cancer-free survival rate as well as a poorer survival rate. Two patients with a long survival, who have been free from cancer for more than 5 years, showed a low AgNOR score (1.6, 1.7).

Conclusions: The AgNOR method is simple, low-cost and can easily be applied to paraffin-embedded sections. Therefore, this score is considered to be useful in identifiying malignant potentiality in intrahepatic cholangiocellular carcinoma.