Tumor-infiltrating CD8+ T cells combined with tumor-associated CD68+ macrophages predict postoperative prognosis and adjuvant chemotherapy benefit in resected gastric cancer

Background Tumor-infiltrating immune cells are present in various malignant tumors, but their clinical significance in gastric cancer (GC) remains unclear. This study aimed to investigate the prognostic significance of tumor-infiltrating lymphocytes (TILs) and tumor-associated macrophages (TAMs). Methods Using a prospective database containing 401 cases of GC, we evaluated TIL (cluster of differentiation 8 (CD8) expression) and TAM (cluster of differentiation 68 (CD68) expression) statuses via immunohistochemical staining. Results Compared with CD8+ TIL-negative cases (n = 196, 48.6%), CD8+ TIL-positive cases (n = 205, 51.1%) showed significantly better recurrence-free survival (RFS) [log-rank ppn = 217, 54.1%), CD68+ TAM-positive cases (n = 184, 45.9%) had significantly poor RFS [log-rank pp Conclusions CD8+ TIL and CD68+ TAM statuses were identified as independent prognostic factors that may be integrated into the current TNM staging system to refine risk stratification and to better predict the survival benefit from PAC in patients with GC. Trial registration The current controlled trial was registered at ClinicalTrials.gov (ID: NCT02327481) on December 30, 2014.