Comparison of bromodeoxyuridine and proliferating cell nuclear antigen labeling in gastric carcinoma

The proliferative activity of human gastric carcinoma was measured by means of in vitro incorporation of the thymidine analogue, 5-bromo-2'-deoxyuridine (BrdU), into the newly-synthesized DNA of fresh tumors and immunohistochemical staining of proliferating cell nuclear antigen (PCNA) using avidin-biotin peroxidase method. Eighty-two cases of surgically resected human gastric carcinomas consisting of 18 various histologic types were subjected to study. The mean BrdU labelling index (LI) and PCNA LI were 22.9% and 39.1%, respectively. The correlation between BrdU LI and PCNA LI was statistically significant (correlation coefficient mu = 0.61334, p = 0.0001). We concluded that immunohistochemical staining for PCNA may become a practical method instead of in vitro or in vivo BrdU labeling to assess the proliferation fraction of the gastric cancer patient.