Table 3.
Comparison of Baseline PD-L1 Expression and CD8+ TILs in Patients with EGFR versus KRAS Mutations
| EGFR-Mutant (N=62) |
KRAS-Mutant (N=65) |
P Value | |
|---|---|---|---|
| PD-L1 Positive | |||
| PD-L1+ (≥ 50%) | 7 (11%) | 11 (17%) | 0.449 |
| PD-L1+ (≥5%) | 10 (16%) | 20 (31%) | 0.062 |
| CD8+ TILs (Immunohistochemistry; IHC)a | |||
| 0 | 17 (35%) | 18 (32%) | 0.159 |
| 1+ | 29 (60%) | 26 (46%) | |
| 2+ | 2 (4.2%) | 11 (20%) | |
| 3+ | 0 (0%) | 1 (1.8%) | |
| CD8+ TILs (Image-Based)b per mm2 | |||
| Median (Range) |
185.1 (6.1–1161.9) |
330.1 (8.5–2567.3) |
0.011 |
| Concurrent PD-L1 Expression & CD8+ TILs (IHC) | |||
| PD-L1+ (≥ 50%) & High CD8+ TILs (grade 2–3) | 1/48 (2.1%) | 7/56 (12%) | 0.066 |
| PD-L1+ (≥ 5%) & High CD8+ TILs (grade 2–3) | 1/48 (2.1%) | 11/56 (20%) | 0.005 |
| Concurrent PD-L1 Expression & CD8+ TILs (Image-Based) | |||
| PD-L1+ (≥ 50%) & Highc CD8+ TILs per mm2 | 2/46 (4.3%) | 10/56 (18%) | 0.061 |
| PD-L1+ (≥ 5%) & Highc CD8+ TILs per mm2 | 2/46 (4.3%) | 15/56 (27%) | 0.003 |
a
Cytology specimens and those with no tissue on the slide were excluded from the evaluation of CD8+ tumor infiltrating lymphocytes (TILs).
b
Cytology and markedly fragmented biopsy specimens and those with no tissue on the slide were excluded from the evaluation of CD8+ TILs.
c
High CD8+ TILs defined as ≥ median in the pre-treatment control (KRAS-mutant) population (330.1 per mm2).
Slight differences in the number of specimens analyzed using immunohistochemistry versus quantitative CD8 analysis reflect differences in tissue adequacy for analysis.
Percentages may not equal 100% due to rounding.