Clinical significance of spontaneous apoptosis in advanced gastric adenocarcinoma

Abstract

Spontaneous apoptosis has been detected in gastric carcinoma. However, the clinicopathological significance of this remains unclear. The objective of this study was to investigate the correlation between spontaneous apoptosis and the clinicopathologic and biologic characteristics of advanced gastric carcinoma. In addition, the prognostic significance of spontaneous apoptosis of tumors was evaluated. The occurrence of apoptotic cell death (apoptotic index [AI]) in 97 patients with advanced gastric carcinoma was analyzed by the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate biotin nick end labeling method. The Ki-67 labeling index (LI), expression of p53 and p21, DNA ploidy pattern, microvessel density (MVD), density of dendritic cells (DCs) in tumors, and degree of lymphocytic infiltration (LI) of the tumors were compared with the AI for each patient. In addition, the prognostic significance of AI was evaluated in these patients. The mean AI of the 97 tumors was 2.05% (range, 0-11.31%). Statistical analyses revealed significant correlations between the AIs and the Ki-67 LIs (P = 0.0004) and between the AIs and the density of DCs (P = 0.0007), as well as an inverse correlation between the AIs and the intratumoral MVD (P = 0.0064). In addition, the AI of 47 tumors with high grade LI (2.94+/-2.51%) was significantly higher than that of 50 tumors with low grade LI (1.22+/-0.93%) (P<0.0001). However, the authors failed to find a significant correlation between the AIs and expression of p53 and p21 and the DNA ploidy pattern. In 93 surviving patients, the 5-year survival rate of 45 patients who had tumors with high AIs (> or =1.47; 82%) was significantly better than that of 48 patients who had tumors with low AIs (<1.47; 60%) (P = 0.0264). The findings of the current study suggest that the tumors with low neovascularization and high local immunoreactivity may regulate their progression by apoptosis. Moreover, less extensive apoptosis in gastric adenocarcinoma may contribute to disease progression and could be correlated with a poorer prognosis.