Intranodal antitumor immunocyte infiltration in node-negative gastric cancers

The status and role of immunocytes and dendritic cells in regional lymph no des in patients with gastric cancer are examined in this study, Forty-nine patients with gastric cancer who underwent curative resection were enrolled in the present study. These patients had no lymph node metastases accordin g to a histological examination. The infiltration of natural killer (NK) ce lls, dendritic cells, and MIB-1-positive immunocytes was investigated. Base d on the Japanese Classification of Gastric Carcinoma, regional lymph nodes were divided into three compartments: (a) compartment 1 (lymph node statio n numbers 1-6); (b) compartment 2 (lymph node station numbers 7-12); and (c ) compartment 3 (lymph node station numbers 14 and 16). Dendritic cells and MIB-1-positive immunocytes infiltrated compartment 1 lymph nodes in increa sed numbers compared with the lymph nodes of compartments 2 or 3 (P ( 0,05) , Conversely, intranodal NK cell infiltration did not differ significantly among the three compartments. The incidence of intranodal dendritic and MIB -1-positive cell infiltration in patients with submucosal gastric cancer wa s significantly higher than in patients with tumors that invaded beyond the muscularis propria, The decreased expression of these immunological marker s correlated well with recurrent disease, regardless of tumor depth. The im munocyte level is higher in lymph nodes near the primary tumor (compartment 1) than in those that are distant from the tumor (compartments 2 and 3), T his pertains to all three markers, i.e,, NK, dendritic, and MIB-1-positive cells, Unlike dendritic and MIB-1-positive cells, intratumoral infiltration of NK cells did not correlate well with either lymph node compartment or t he depth of tumor invasion. The degree of NK cell infiltration may be direc tly associated with antitumor effects, especially in compartment 1, A decre ase in all three markers is associated with tumor recurrence.