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

Abstract EN

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 (p<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, p<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 (p=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, p<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.