Tumor-infiltrating B cell is associated with the control of progression of gastric cancer.

This study aimed to further explore the clinicopathological correlation of B cell infiltration in gastric cancer (GC) and its impact on prognostic. By immunohistochemical method, CD20+ B cells, CD3+ T cells, CD66b+ tumor-associated neutrophils, CD163+ tumor-associated macrophages, and CD57+ natural killer cells were analyzed in consecutive sections of 584 GC tissues and 69 normal adjacent tissues. Kaplan-Meier and Cox regression analyses determined the relationship between clinical relevance or prognosis and B cell infiltration. The correlation between total B cell infiltration and various T cell subtype infiltration in GC tissues from 407 patients in the TCGA data was also analyzed. Kaplan-Meier and Cox regression analyses determined the effects of total B cell infiltration and various B cell subtype infiltration on the prognosis of patients with GC. The infiltration level of CD20+ B cells was positively correlated with that of T cells (risk ratio [RR] = 0.0930), especially CD4+ T cells and CD8+ T cells (P < 0.05). A high level of CD20+ B cell infiltration was significantly associated with low lymph node involvement and low TNM stage (P < 0.05). High levels of CD20+ B cell infiltration were significantly associated with improvements in overall survival and disease-free survival. Univariate Cox regression and multivariate Cox regression analysis showed that CD20+ B cell infiltration was an independent protective factor of prognosis. Higher levels of class-switched memory B cell and plasma cell also reflected better overall survival, and class-switched memory B cell and plasma cell were independent protective factors for prognosis. The findings indicate that B cell infiltration in GC, especially switched memory B cells and plasma cells, has a significant effect on tumor progression and prognosis.