Table 1. Profile of recruited patients.
| Characteristic | N = 13 | % of total |
|---|---|---|
| Age | ||
| Median, years | 73 | - |
| Range | 58–88 | - |
| Sex | ||
| Male | 9 | 69.2 |
| Female | 4 | 30.8 |
| The location of cancer | ||
| Buccal mucosa | 1 | 7.7 |
| Maxillary gingiva | 4 | 30.8 |
| Mandibular gingiva | 3 | 23.1 |
| Tongue | 3 | 23.1 |
| Floor of mouth | 2 | 15.4 |
| Depth of tumor invasion | ||
| T1 | 2 | 15.4 |
| T2 | 2 | 15.4 |
| T3 | 2 | 15.4 |
| T4 | 7 | 53.8 |
| Lymph node metastasis | ||
| N0 | 8 | 61.5 |
| N1 | 2 | 15.4 |
| N2 | 2 | 15.4 |
| N3 | 1 | 7.7 |
| Cancer stage | ||
| Ⅰ | 2 | 15.4 |
| Ⅱ | 1 | 7.7 |
| Ⅲ | 2 | 15.4 |
| Ⅳ | 8 | 61.5 |
| Distant metastasis after operation | ||
| Positive | 4 | 30.8 |
| Negative | 9 | 69.2 |
| The number of CTC | ||
| Median | 4 | - |
| Range | 1–32 | - |
| The amount of cfDNA (ng/mL) | ||
| Median | 3.4 | - |
| Range | 1.1–10.6 | - |