Table 4.
Relationship of tumor cell PD-L1 expression to clinical and immune parameters in primary breast carcinomas
| Tumor cell PD-L1 expressiona |
|||
|---|---|---|---|
| PD-L1− | PD-L1+ | P b | |
| Total evaluable tumors (n = 43) | 34 (79%) | 9 (21%) | |
| Tumor phenotype | .19 | ||
| Luminal | 13 (38%) | 1 (11%) | |
| HER-2+ | 9 (26%) | 5 (56%) | |
| Basal-like | 12 (35%) | 3 (33%) | |
| Median age (y, range) | 57 (33-79) | 48 (36-88) | .82 |
| Patient race | .18 | ||
| Black | 13 (38%) | 2 (22%) | |
| White | 21 (62%) | 6 (67%) | |
| Other | 0 | 1 (11%) | |
| Tumor grade | .04 | ||
| 1 | 0 | 0 | |
| 2 | 12 (35%) | 0 | |
| 3 | 22 (65%) | 9 (100%) | |
| Median tumor size (cm, range) | 2.5 (1.1-12) | 2.1 (1.4-4.5) | .08 |
| Multifocal disease | 7 (21%) | 1 (11%) | 1.00 |
| Stage | 1.00 | ||
| 1 | 7 (21%) | 2 (22%) | |
| 2 | 21 (62%) | 6 (67%) | |
| 3 | 6 (18%) | 1 (11%) | |
| Associated DCIS | n = 7 | n=3 | .008 |
| PD-L1 negative | 7 (100%) | 0 | |
| PD-L1 positive | 0 | 3 (100%) | |
| TIL intensity scorec | 0 | 0 | .002 |
| 0 | 7 (21%) | 0 | |
| Focal: 1 | 19 (56%) | 1 (11%) | |
| Moderate: 2 | |||
| Diffuse: 3 | 8 (24%) | 8 (89%) | |
| PD-L1+ TILd | .04 | ||
| None or focal: 0-1 | 19 (56%) | 1 (11%) | |
| Moderate: 2 | 13 (38%) | 7 (78%) | |
| Diffuse: 3 | 2 (6%) | 1 (11%) | |
| Lymphoid aggregate score | <.001 | ||
| 0 | 20 (59%) | 0 | |
| Focal: 1 | 8 (24%) | 2 (22%) | |
| Moderate: 2 | 3 (9%) | 0 | |
| Germinal centers: 3 | 3 (9%) | 7 (78%) | |
| Quantitative TIL count/mm2 | |||
| Total CD3: median (range) | 769 (71-3944) | 2460 (1506-8465) | .02 |
| Total CD4: median (range) | 1053 (67-6369) | 2907 (2240-13 639) | .04 |
| Total CD8: median (range) | 777 (2-3169) | 1462 (643-3842) | .002 |
| Total FoxP3: median (range) | 318 (64-1115) | 965 (247-1822) | .02 |
| Total CD20: median (range) | 207 (6-1959) | 846 (58-5776) | .16 |
| CD8/FoxP3 ratio: median (range) | 2.2 (0.8-7.9) | 2.2 (0.9-5.3) | .99 |
| CD4/FoxP3 ratio: median (range) | 4.2 (0.86-11.0) | 6.5 (2.4-9.08) | .16 |
Abbreviations: DCIS, ductal carcinoma in situ; HER-2, human epidermal growth factor receptor 2; TIL, tumor-infiltrating lymphocytes and macrophages.
Tumor cells were considered PD-L1+ if greater than or equal to 5% of cells had membranous PD-L1 labeling.
The P values of categorical variables are derived from Fisher exact test, and the P values of continuous variables are derived from 2-sided t tests.
Immune infiltrates included TILs and accompanying histiocytes and were scored as “none” (0), “focal” (1), “moderate” (2), or “diffuse” (3); see “Materials and methods” section.
The proportion of TILs expressing PD-L1 was graded as “none” (0), “focal” (1); “moderate” (2), or “severe” (3).