Clinical Significance of Preoperative CD8+ Central Memory T Cells for Operable Pancreatic Adenocarcinoma

Abstract

Background: CD8+ central memory T cells (CD8+ Tcm) have superior roles in antitumor immunity. The purpose of this study was to detect CD8+ Tcm in the peripheral blood of patients with pancreatic adenocarcinoma and to analyze its clinic significance. Methods: Seventy two patients with primary pancreatic adenocarcinoma who underwent curative operation were enrolled. The percentage and absolute count of CD8+ Tcm in the peripheral blood of patients were analyzed through flow cytometry and the multiplatform predicate method, respectively, and these values were compared to those of the healthy control. The correlation between CD8+ Tcm and survival was analyzed by the Kaplan-Meier with log-rank test and Cox's regression methods, respectively. Results: The percentage of CD8+ Tcm from pancreatic adenocarcinoma was higher than the healthy control (16.79 ± 9.43% vs. 11.41 ± 4.67%, p = 0.028), which also had a relationship with the lymph node status. Patients with high-level CD8+ Tcm had a significantly higher median survival than those with low CD8+ Tcm (18 vs. 12 months, p = 0.004); a similar result was obtained in absolute CD8+ Tcm count. It was revealed in multivariate analysis that both percentage and absolute count of CD8+ Tcm was an independent prognostic factor for overall survival. Conclusions: CD8+ Tcm can be considered an independent prognostic factor for operable pancreatic adenocarcinoma, which was also associated with the lymph nodes metastasis.