Intratumoral CD8+ Cytotoxic Lymphocyte Is a Favorable Prognostic Marker in Node-Negative Breast Cancer

Abstract

285 (85.8%) patients showed strong CD8+ CTLs infiltrate positive status. Univariate analysis showed that CD8+ CTLs had statistically significant association with DFS (P = 0.004, hazard ratio [HR] = 0.454, 95% confidence interval [CI] = 0.265-0.777) and OS (P = 0.014, HR = 0.430, 95% CI = 0.220-0.840) in the entire cohort. The significance of CD8+ CTLs was especially strong in ER negative, HER-2 negative and ER, PR, HER-2 triple-negative breast cancers. In Kaplan-Meier analysis, CD8+ CTLs had significant effect on prognosis of patients (Log-rank test: P = 0.003 for DFS and P = 0.011 for OS), independent of established clinical factors for DFS (P = 0.002, HR = 0.418, 95% CI = 0.242-0.724) as well as for OS (P = 0.009, HR = 0.401, 95% CI = 0.202-0.797).