Immune response in breast cancer brain metastases and their microenvironment: the role of the PD-1/PD-L axis

Breast Cancer Research

Table 3 Assessment of selected parameters of immune response in breast cancer brain metastasis and the brain microenvironment

Variable	Number	%
Reactive astrocytes (glial fibrillary acid protein expression)	83/84	99
No	15	18
Yes	60	71
No neuronal tissue	8	10
Stromal tumor infiltrating lymphocytes^a (CD4+)	81/84	96
Median	49
IQR	23–121
Stromal tumor infiltrating lymphocytes^a (CD8+)	82/84	98
Median	69
IQR	38–127
Microglia/macrophages^a (CD68+)	77/84	92
Median	76
IQR	57–104
PD-1 expression on tumor infiltrating lymphocytes	74/84	88
No	57	68
Yes	17	20
Not determined	10	12
PD-L1 expression on BCBM	78/84	93
H-score; mean (range)	27.1 (0–200)
PD-L2 expression on BCBM	78/84	93

IQR interquartile range, PD-1 programmed cell death protein 1 receptor, PD-L1 programmed cell death protein 1 receptor ligand 1, PD-L2 programmed cell death protein 1 receptor ligand 2, BCBM breast cancer brain metastases. ^aDensity was scored at magnification × 400 (ocular × 10 with an objective × 40 high-power field (HPF) per 1 mm²

ISSN: 1465-542X