Table 1.
Comparison of histopathologic characteristics among patients with dMMR/MSI-H according to treatment response
| Histopathologic characteristic | Responder (n=15) | Non-responder (n=12) | p-value |
|---|---|---|---|
| Histologic subtype | |||
| Well-differentiated or moderately-differentiated | 10 (66.7) | 4 (33.3) | 0.003 |
| Poorly-differentiated | 4 (26.7) | 0 | |
| Mucinous or signet-ring cell carcinoma | 1 (6.6) | 8 (66.7) | |
| Neutrophil infiltration grade | |||
| 0 or 1 | 8 (53.3) | 11 (91.7) | 0.043 |
| 2 or 3 | 7 (46.7) | 1 (8.3) | |
| Lymphocyte infiltration grade | |||
| 0 or 1 | 6 (40.0) | 12 (100) | 0.001 |
| 2 or 3 | 9 (60.0) | 0 | |
| Crohn-like lymphoid aggregate | |||
| Absent | 6 (40.0) | 9 (75.0) | 0.120 |
| Present | 9 (60.0) | 3 (25.0) | |
| Tumor border | |||
| Expansile | 8 (53.3) | 0 | 0.003 |
| Infiltrative | 7 (46.7) | 12 (100) | |
| Lymphovascular invasion | |||
| Absent | 8 (53.3) | 7 (58.3) | > 0.99 |
| Present | 7 (46.7) | 5 (41.7) | |
| PD-L1 status | 12 | 7 | |
| PD-L1 immunohistochemistry | |||
| Negative | 2 (16.7) | 3 (42.9) | 0.305 |
| Positive | 10 (83.3) | 4 (57.1) | |
| Combined proportion score | 5 (0–30) | 5 (0–15) | 0.290 |
| RAS and RAF mutation | 13 | 11 | |
| KRAS | 7 (53.9) | 5 (45.5) | 0.827 |
| NRAS | 0 | 1 (9.0) | |
| BRAF V600E | 1 (7.6) | 0 | |
| None | 5 (38.5) | 5 (45.5) | |
| Tumor mutational burden | 7 | 6 | |
| TMB (mutations/Mb) | 110.9 (57.8–176.6) | 101.6 (50.0–135.9) | 0.656 |
Values are presented as number (%) or median (range). dMMR, deficient DNA mismatch repair; MSI-H, microsatellite instability–high; PD-L1, programmed death-ligand 1; TMB, tumor mutational burden.