Table 2.
Molecular profile of primary tumors and brain metastases.
| Molecular Status | Primary Tumors (n = 82) | BM (n = 38) |
|---|---|---|
| KRAS status | ||
| Wild-type, n (%) | 35 (44) | 10 (26) |
| Mutant, n (%) | 44 (56) | 28 (74) |
| KRAS exon 2 at codon 12 | ||
| G12D | 14 (18) | 9 (23) |
| G12V | 14 (18) | 8 (21) |
| G12A | 5 (6) | 3 (8) |
| G12S | 3 (4) | 0 |
| G12C | 1 (1) | 1 (3) |
| G12R | 1 (1) | 1 (3) |
| KRAS exon 2 at codon 13 | ||
| G13D | 2 (3) | 3 (8) |
| G13R | 1 (1) | 1 (3) |
| KRAS exon 3 at codon 61 | 3 (4) | 2 (5) |
| KRAS exon 4 at codon 146 | 0 | 0 |
| Missing, n | 3 | 0 |
| NRAS status | ||
| Wild-type, n (%) | 74 (94) | 34 (89) |
| Mutant, n (%) | 5 (6) | 4 (11) |
| NRAS exon 2 at codon 12 or 13 | 1 (1) | 1 (3) |
| NRAS exon 3 at codon 61 | 4 (5) | 3 (8) |
| Missing, n | 3 | 0 |
| BRAF exon 15 at codon 600 | ||
| Wild-type, n (%) | 74 (94) | 36 (95) |
| Mutant, n (%) | 5 (6) | 2 (5) |
| Missing, n (%) | 3 | 0 |
| MMR status | ||
| pMMR, n (%) | 70 (95) | 36 (95) |
| dMMR, n (%) | 4 (5) | 2 (5) |
| Missing, n | 8 | 0 |
| cMET expression | ||
| Negative (0, 1+, 2+/3+ with FISH negative), n (%) | 76 (100) | 37 (100) |
| Positive (2+, 3+ with FISH positive), n (%) | 0 | 0 |
| Missing, n | 6 | 1 |
| HER-2 expression | ||
| Negative (0, 1+, 2+ with FISH negative), n (%) | 74 (99) | 37 (100) |
| Positive (2+ with FISH positive, 3+), n (%) | 1 (1) | 0 |
| Missing, n | 7 | 1 |
| ALK expression | ||
| Negative (0, 1+/2+/3+ with FISH negative), n (%) | 76 (100) | 37 (100) |
| Positive (1+/2+/3+ with FISH positive), n (%) | 0 | 0 |
| Missing, n (%) | 6 | 1 |
| ROS1 expression | ||
| Negative (0, 1+/2+/3+ with FISH negative), n (%) | 74 (100) | 37 (100) |
| Positive (1+/2+/3+ with FISH positive), n (%) | 0 | 0 |
| Missing, n | 8 | 1 |
| PD-1 expression | ||
| Negative, n (%) | 64 (86) | 37 (100) |
| Positive, n (%) | 10 (14) | 0 |
| Missing, n | 8 | 1 |
| PD-L1 expression | ||
| Negative, n (%) | 68 (93) | 35 (95) |
| Positive, n (%) | 5 (7) | 2 (5) |
| Missing, n | 9 | 1 |
| CD3 expression | ||
| Median rate, % (range) | 30 (0–80) | 11 (0–60) |
| Missing, n | 11 | 1 |
| CD8 expression | ||
| Median rate, % (range) | 11 (0–70) | 3 (0–50) |
| Missing, n | 7 | 2 |
Abbreviations: IHC, Immunohistochemistry; FISH, Fluorescence in situ hybridization; MMR, Mismatch repair; pMMR, Proficient Mismatch Repair; dMMR, Deficient Mismatch Repair.