Table 1.
Baseline characteristics.
| Development dataset | Internal validation dataset | Clinical validation dataset | External validation dataset | p value | |
|---|---|---|---|---|---|
| Number of photographs | 5775 | 401 | 666 | 402 | .. |
| Stage | 0.033 | ||||
| Number of T1 OCSCC patients | 459 | 101 | 51 | .. | .. |
| Number of T2 OCSCC patients | 471 | 27 | 54 | .. | .. |
| Number of T3 OCSCC patients | 110 | 7 | 18 | .. | .. |
| Number of T4 OCSCC patients | 82 | 1 | 8 | .. | .. |
| Number of photographs for which age was unknown | 3735 | 224 | 316 | 402 | .. |
| Mean age, years (range) | 55 (19–88) | 58 (26–89) | 55 (21–83) | .. | <0.0001 |
| Lesion location | 0.005 | ||||
| Squamous cell carcinoma of lip | 99 (2%) | 8 (2%) | 6 (1%) | 22 (6%) | .. |
| Squamous cell carcinoma of tongue | 901 (16%) | 83 (20%) | 120 (18%) | 37 (9%) | .. |
| Squamous cell carcinoma of gum | 272 (5%) | 21 (5%) | 43 (7%) | 34 (8%) | .. |
| Squamous cell carcinoma of floor of mouth | 202 (3%) | 16 (4%) | 9 (1%) | 12 (3%) | .. |
| Squamous cell carcinoma of palate | 112 (2%) | 10 (3%) | 12 (2%) | 10 (2%) | .. |
| Squamous cell carcinoma of pharynx | 40 (1%) | 5 (1%) | 18 (3%) | 1 (1%) | .. |
| Squamous cell carcinoma of other or unspecified parts of mouth | 429 (7%) | 36 (9%) | 66 (10%) | 38 (9%) | .. |
| Non-OCSCC oral mucosal diseases* | 0 | 0 | 77 (11%) | 0 | .. |
| Normal oral mucosa | 3720 (64%) | 222 (56%) | 315 (47%) | 248 (62%) | .. |
OCSCC = oral cavity squamous cell carcinoma.
Data are n (%), unless otherwise stated.
⁎
Non-OCSCC oral mucosal diseases included non-OCSCC malignancies, epithelial dysplasia and benign lesions that were detailed in the appendix.