Prognostic Value of Natural Killer Cell and Dendritic Cell Infiltration in Gastric Cancer

ABSTRACT

PURPOSE: Natural killer cells (NKC) and dendritic cells(DC) have non-specific cytotoxic effect against various tumor such as breast cancer, colorectal cancer and lung cancer. However, the relationsjip between the infiltration of these cells and the prognosis of gastric cancer has not yet been elucidated. Therefore the aim of this study is to assess the prognostic impact of NKC and DC infiltration in gastric cancer patient. METHODS: Ninety-seven patients who had undergone a gastrectomy (radical subtotal gastrectomy or radical total gastrectomy) at Yonsei Wonju Christian Hospital between Jan. 1995 and Dec. 1995 were enrolled in the study. Immunohistochemical staining was performed for evaluation of NKC infiltration with CD57 antibody and of DC infiltration with S-100 protein. In DC, the number of S-100 protein positive DC was graded as either low dendritic cell infiltration(0 to 20) or high dendritic cell infiltration (over 20 cells) under high power microscopy (x400 HPF). In NKC, a total of 25 areas containing pericancerous tissue were selected for determining the number of NKC infiltration, after which patients were classified as either low NKC infiltraion (0 to 25) or high NKC infiltration (over 25 cells). The Kaplan-Meier method was used to obtain survival curve and multivariated analysis were performed using Cox regression model. RESULTS: The 5-year survival rate was 75.0% in patients with high infiltration of NKC, 45.3% in those with low infiltration of NKC, 80.0% in those with high infiltration of DC and 43.8% in those with low infiltration of DC. These results were statistically different (P<0.01). However multivariate analysis did not show NKC and DC infiltration to be significant prognostic factors. CONCLUSION: NKC and DC intratumoral infiltration of gastric cancer was positively correlated with survival in this study. Although the prognostic significances of NKC and DC intratumoral infiltration were P<0.01 in both NKC and DC in univariated analysis, these results were not permitted as independent prognostic factors in multivariated analysis.