Proliferation Associated Antigen In Gastric Cancer

Using the PCNA labeling index (PCNA LI), thymidine kinase activity, expression of Topoisomerase II alpha and of Ki-67, and DNA ploidy, we evaluated the significance as prognostic factors in gastric cancer. The average rate of PCNA (proliferating cell nuclear antigens) LI in gastric cancer was 52.4 +/- 28.3%. The PCNA LI was lower in signet ring cell cancer than in moderately or poorly differentiated tubular adenocarcinomas. The PCNA LI was lower in mucosal cancer than in advanced gastric cancer and was lower in gastric cancer without lymph node metastasis than that with lymph node metastasis. The PCNA LI closely correlated with the number of metastatic lymph nodes (p<0.001). According to TNM stage, the PCNA LI of stage Ia cancer was lower than those of stage II (p<0.05), IIIa, mb and IV (p<0.001). However, the rate of patient survival did not correlate with the PCNA LI. The PCNA LI correlated with activity of thymidine kinase, which was a rate-limiting enzyme of DNA synthesis. The Topoisomerase II alpha and Ki-67 by immunohistochemical staining was closely correlated each other. According to immunohistochemical staining Topoisomerase II alpha and Ki-67 were shown to be closely correlated with each other. However, the expression of Topoisomerase II alpha and Ki-67 in gastric cancer tissues did not correlate to other prognostic factors. The proliferative activity represented by the PCNA labeling index correlated with various pathologic prognostic factors, such as the invasion depth, lymph node metastasis and molecular markers, but was not an independent prognostic factor in gastric cancer.