Expression of PD-1 on CD4 Tumor-Infiltrating Lymphocytes in Tumor Microenvironment Associated with Pathological Characteristics of Breast Cancer.

OBJECTIVE

This study aimed to investigate the correlation of CD4/PD-1 or CD4/PD-1 tumor-infiltrating lymphocytes with pathological characteristics in breast cancer patients.

METHODS

A cross-sectional study consecutively recruited 133 patients with invasive ductal breast cancer. The expression of CD4, programmed cell death protein 1 (PD-1), CK7, CK20, E-cadherin, or Ki-67 was detected by immunohistochemistry. The associations between CD4/PD-1 or CD4/PD-1 tumor-infiltrating lymphocytes and pathological characteristics were evaluated.

RESULTS

Elderly patients intended to have a lower level of CD4/PD-1 tumor-infiltrating lymphocytes ( < 0.05). Patients with positive E-cadherin expression had higher median cell counts of CD4/PD-1 tumor-infiltrating lymphocytes than patients with negative E-cadherin expression (30/HPF versus 10/HPF, < 0.05). Counts of CD4/PD-1 tumor-infiltrating lymphocytes had a significant correlation with Ki-67 index that the correlation coefficient was 0.29 ( = 0.001). Positive CK20 expression was related to a higher level of CD4/PD-1 tumor-infiltrating lymphocytes than negative CK20 expression (73/HPF versus 30/HPF, < 0.05).

CONCLUSION

CD4/PD-1 or CD4/PD-1 tumor-infiltrating lymphocytes showed diverse association with pathological features of breast cancer. CD4/PD-1 tumor-infiltrating lymphocytes had a significant relationship with Ki-67 expression whereas CD4/PD-1 tumor-infiltrating lymphocytes had a significant relationship with E-cadherin expression. Further studies are warranted to explore the immunomodulatory effects of phenotypes of CD4 T cell subsets in breast cancer.