Table 2.
Demographic characteristics and tumor mutation burdens of the study cohort (n = 62)
| Total | TMB high/intermediate | TMB low | p value | |||||
|---|---|---|---|---|---|---|---|---|
| Case # | 62 | 30 | 32 | |||||
| Age | 53.8 | 30–78 | 54.6 | 31–74 | 53.1 | 30–78 | NS | |
| Location | Primary | 13 | 21.0% | 6 | 20.0% | 7 | 21.9% | NS |
| Metastatic | 49 | 79.0% | 24 | 80.0% | 25 | 78.1% | NS | |
| Biomarkers | ER-positive | 36 | 58.1% | 19 | 63.3% | 17 | 53.1% | NS |
| PR-positive | 18 | 29.0% | 9 | 30.0% | 9 | 28.1% | NS | |
| HER2-positive | 5 | 8.1% | 2 | 6.7% | 3 | 9.4% | NS | |
| Triple-negative | 22 | 35.5% | 8 | 26.7% | 14 | 43.8% | NS | |
| Histologic type | Ductal, NOS | 52 | 83.9% | 26 | 86.7% | 26 | 81.3% | NS |
| Lobular | 6 | 9.7% | 3 | 10.0% | 3 | 9.4% | NS | |
| Metaplastic | 2 | 3.2% | 1 | 3.3% | 1 | 3.1% | NS | |
| Neuroendocrine | 2 | 3.2% | 0 | 0.0% | 2 | 6.3% | NS | |
| Gene mutation | p53 | 37 | 59.7% | 20 | 66.7% | 17 | 53.1% | NS |
| PIK3CA | 21 | 33.9% | 9 | 30.0% | 12 | 37.5% | NS | |
| BRCA (1/2) | 6 | 9.7% | 5 | 16.7% | 1 | 3.1% | 0.0002 | |
| Nuclear grade | 2.5 | 2–3 | 2.5 | 2–3 | 2.4 | 2–3 | NS | |
| Tumor infiltrating lymphocytes | 7.1% | 0–60% | 11.4% | 0–60% | 3.5% | 0–10% | 0.0018 | |
Abbreviations: TMB tumor mutation burden, ER estrogen receptor, PR progesterone receptor