Table 2. Clinicopathologic and genomic factors associated with ctDNA detection.
| Characteristics | Positive (n=7) | Negative (n=13) | P value |
|---|---|---|---|
| Age, years | |||
| Median | 43 | 40 | 0.7123 |
| Mean ± SD | 47.5±4.83 | 46±3.71 | |
| >42 year, n (%) | 4 (57.1) | 6 (46.2) | 1 |
| Subtypes, n (%) | 0.376 | ||
| Luminal A | 0 (0) | 3 (23.1) | |
| Luminal B | 2 (28.6) | 5 (38.4) | |
| HER2+ | 3 (42.8) | 3 (23.1) | |
| TNBC | 2 (28.6) | 2 (15.4) | |
| Tumor size | |||
| Median | 2.3 | 2.2 | 0.876 |
| Mean ± SD | 2.54±0.46 | 2.72±0.32 | |
| >2.25 cm, n (%) | 4 (57.1) | 6 (46.2) | 1 |
| Stage, n (%) | 0.612 | ||
| I/II | 5 (71.4) | 9 (69.2) | |
| III | 2 (28.6) | 4 (30.8) | |
| N-stage, n (%) | 1 | ||
| N0 | 3 (42.9) | 6 (46.2) | |
| N1/N2 | 4 (57.1) | 7 (53.8) | |
| PIK3CA, n (%) | 0.328 | ||
| mut | 1 (14.3) | 6 (46.2) | |
| wt | 6 (85.7) | 7 (53.8) | |
| ERBB2, n (%) | 1 | ||
| mut | 2 (28.6) | 3 (23.1) | |
| wt | 5 (71.4) | 10 (76.9) | |
| HRR, n (%) | 0.085 | ||
| mut | 6 (85.7) | 6 (46.2) | |
| wt | 1 (14.3) | 7 (53.8) | |
| TMB | |||
| Median | 2.88 | 0.97 | 0.17 |
| Mean ± SD | 3.84±1.19 | 2.58±0.81 | |
| >1.92 mut/Mb, n (%) | 6 (85.7) | 5 (38.5) | 0.0427 |
HER2 (also known as ERBB2), human epidermal growth factor receptor 2; TNBC, triple negative breast cancer; mut, mutation; wt, wild type; HRR, homologous recombination repair; TMB, tumor mutational burden.