Natural killer cells are associated with prognosis in triple-negative breast cancer patients

Abstract Objective:Immune cells play an important role in anti-tumor activity. We aimed to investigate the expression of CD4+ and CD8+ T cells, natural kill (NK) cells, and interleukin-27 (IL-27) in breast cancer tissues, and to explore their relationship with clinical characteristics and patients’ prognoses.Methods:Immunohistochemistry was used to detect the expression levels of CD4+ and CD8+ T cells, NK cells, and IL-27 in a total of 198 breast cancer patients.Results:It was found that the number of positive NK cells was highest in patients with triple negative breast cancer (TNBC). In the Luminal A breast cancer group: the higher the histological grade, the higher the number of positive cases of CD4+ T cells; the higher the clinical stage, the higher the percentage of positive CD8+ T cells. In the Luminal B breast cancer group: the higher the histological grade, the higher the number of positive cases of CD8+ T cells; the higher the clinical stage, the higher the number of positive cases of CD8+ T cells. In the grouping of HER-2 breast cancer, patients with lymph node metastasis had higher CD8+ T cell positive cases; larger tumor volume had higher IL-27 positive cases. In TNBC grouping: the larger the tumor volume, the higher the positive ratio of CD8+ T cells; the higher the number of NK cell positive cases in patients with lymph node metastasis; the higher the number of IL-27 positive cases in patients with larger tumor volume. The survival curve showed that the OS rate of NK cell-negative patients was significantly higher than that of NK cell-positive patients.Conclusion:This study shows that infiltrating CD4+ and CD8+ T cells and NK cells in breast cancer tissue are associated with poor patient prognosis, and NK cell-positive TNBC patients with poor prognosis.