Immune Profiles of Tumor Microenvironment and Clinical Prognosis among Women with Triple-Negative Breast Cancer

Background: The impact of the immune landscape of the microenvironment on cancer progression is not well understood for triple-negative breast cancer (TNBC). We, therefore, aimed to examine the association of immune cell enrichment scores as a proxy for immune profiles of tumor microenvironment with TNBC prognosis. Methods: We included 76 patients with TNBC diagnosed between 2008 to 2016 in West China Hospital and 158 patients with TNBC from The Cancer Genome Atlas. On the basis of transcriptome data, we calculated the overall ImmuneScore and type-specific enrichment scores for 34 types of immune cells, using xCell, a gene signature–based method. HRs of recurrence-free survival (RFS) and overall survival (OS) were calculated by Cox proportional hazards models. Results: During the median follow-up time of 2.8 (0.1–9.8) years, 42 patients had a recurrence, and 34 patients died. The overall ImmuneScore and most immune cell enrichment scores were relatively higher in tumors than normal tissues. A higher enrichment score of plasma cells was associated with favorable RFS [HR 0.45; 95% confidence interval (CI), 0.27–0.73] and OS (HR 0.32; 95% CI, 0.17–0.61). The score of CD4+ central memory T cell (Tcm) was negatively associated with RFS (HR 1.52; 95% CI, 1.17–1.97). Besides, CD4+ Tcm enrichment score was higher in invasive tumors that were not ductal/lobular carcinoma (OR 1.59; 95% CI, 1.06–2.37). Conclusions: Our findings suggest that plasma cells and CD4+ Tcm in the tumor microenvironment may play a role in the subsequent progression of TNBC. Impact: This study provides evidence of the role of immune cells in TNBC progression that may have clinical utility.