The argyrophilic nucleolar organizer region (Ag-NOR) score in invasive ductal carcinoma of the pancreas

The biological malignancy of pancreatic carcinoma was evaluated by determining the score of the argyrophilic nucleolar organizer region (Ag-NOR) in resected specimens, and comparing it with the various clinicopathological factors and long-term results of 38 patients who underwent surgical resection for invasive ductal carcinoma of the pancreas between 1977 and 1992, in whom the Ag-NOR could be stained. The Ag-NOR analysis of pancreatic carcinomas from the 38 patients resulted in a mean Ag-NOR score of 3.82±0.62, which was significantly (P<0.01) higher than the mean score of 1.72±0.28 observed in normal pancreatic tissues obtained from 20 of these patients. The mean Ag-NOR score significantly increased in patients with anterior capsular infiltration (s) (P<0.01), posterior tissue infiltration (rp) (P<0.01), and lymph node metastasis (n) (P<0.05) compared to those without these factors. The rate of curability A or B was only 13.0% in patients with a high Ag-NOR score of ≧3.80 in comparison to 66.7% in those with a low Ag-NOR score of <3.80. The 3-year survival rate was significantly (P<0.05) higher in the low Ag-NOR score group than in the high Ag-NOR score group. These results suggest that the Ag-NOR score can serve as an indicator of the biological malignancy of pancreatic carcinoma, and of the patients' prognosis.