Proliferating cell nuclear antigen (PCNA) in pancreatic adenocarcinoma

Interpretation of pancreatic biopsy material can pose substantial difficulties, particularly in the presence of chronic pancreatitis where ductular changes and fibrosis may mimic adenocarcinoma. We examined whether differences in cell kinetics could aid in the distinction between pancreatic carcinoma and chronic pancreatitis. Pancreatic tissue was obtained by percutaneous ultrasonographic guided biopsy. There were a total of thirty-four cases comprising patients with chronic pancreatitis (N = 11) and those with adenocarcinoma (N = 23). The cell cycle activity was determined in sections of routinely paraffin-processed, formalin-fixed biopsy material using immunohistochemical stains for the monoclonal proliferating cell nuclear antigen antibody PCNA (PC 10), a 36 kd nuclear protein synthesized in the late G 1 and S phase. After calculating the PCNA index (% of positively staining nuclei compared to total number of nuclei counted) these were compared in the conditions studied. The PCNA indices in chronic pancreatitis were low with a mean of 5%, while those of adenocarcinoma were 53% (p < 0.001). In conclusion, the PCNA index in pancreatic adenocarcinoma is significantly higher than in chronic pancreatitis. Determination of the PCNA index may be helpful as an adjunct in the diagnosis of problematic cases.