Table 1.
Clinical and Histopathological Features of the PM and SPM
| PM | SPM | P Value* | |
|---|---|---|---|
| Number of patients | 11,356 | 969 | |
| Age at diagnosis, mean ± SD | 49.73 ± 16.69 | 51.12 ± 16.05 | 0.0128 |
| Sex | 0.0130 | ||
| Female | 4885 (43.02%) | 377 (38.91%) | |
| Male | 6471 (56.98%) | 592 (61.09%) | |
| Stage at initial diagnosis | <0.0001 | ||
| 0/I/II | 6752 (59.46%) | 638 (65.84%) | |
| III | 2836 (24.97%) | 206 (21.26%) | |
| IV | 1594 (14.04%) | 99 (10.22%) | |
| Unknown | 174 (1.53%) | 26 (2.68%) | |
| Primary site | <0.0001 | ||
| Head/neck | 2887 (25.42%) | 273 (28.17%) | |
| Trunk | 4611 (40.60%) | 368 (37.98%) | |
| Lower extremity | 2576 (22.68%) | 185 (19.09%) | |
| Upper extremity | 1264 (11.13%) | 119 (12.28%) | |
| Unknown | 18 (0.16%) | 24 (2.48%) | |
| Breslow thickness (mm) | <0.0001 | ||
| ≤1.0 | 3768 (33.18%) | 348 (35.91%) | |
| 1.01–2.00 | 2519 (22.18%) | 173 (17.85%) | |
| 2.01–4.00 | 1697 (14.94%) | 85 (8.77%) | |
| >4.00 | 845 (7.44%) | 34 (3.51%) | |
| Unknown | 2527 (22.25%) | 329 (33.95%) | |
| Ulceration | <0.0001 | ||
| Yes | 1529 (13.46%) | 80 (8.26%) | |
| No | 6902 (60.78%) | 589 (60.78%) | |
| Unknown | 2925 (25.76%) | 300 (30.96%) | |
| Clark level | <0.0001 | ||
| I | 803 (7.07%) | 121 (12.49%) | |
| II | 1934 (17.03%) | 191 (19.71%) | |
| III | 2837 (24.98%) | 209 (21.57%) | |
| IV | 3610 (31.79%) | 224 (23.12%) | |
| V | 565 (4.98%) | 25 (2.58%) | |
| Unknown | 1607 (14.15%) | 199 (20.54%) | |
| Histological type | <0.0001 | ||
| ALM | 113 (1.01%) | 1 (0.10%) | |
| In situ | 634 (5.67%) | 102 (10.65%) | |
| LMM | 345 (3.09%) | 44 (4.59%) | |
| NM | 1853 (16.58%) | 91 (9.5%) | |
| SSM | 4466 (39.96%) | 313 (32.67%) | |
| Others | 520 (4.65%) | 21 (2.19%) | |
| Unknown | 3245 (29.04%) | 386 (40.29%) | |
| Eye color | 0.0010 | ||
| Blue/grey | 2393 (21.07%) | 252 (26.01%) | |
| Brown/black | 1398 (12.31%) | 114 (11.76%) | |
| Green/hazel | 1741 (15.33%) | 159 (16.41%) | |
| Unknown | 5824 (51.29%) | 444 (45.82%) | |
| Early adult hair color | 0.0013 | ||
| Black | 117 (1.03%) | 13 (1.34%) | |
| Dark brown | 1671 (14.71%) | 130 (13.42%) | |
| Light brown | 806 (7.1%) | 99 (10.22%) | |
| Dark red/auburn | 568 (5.0%) | 56 (5.78%) | |
| Light red/ginger | 52 (0.46%) | 4 (0.41%) | |
| Fair/blonde | 2243 (19.75%) | 214 (22.08%) | |
| Unknown | 5899 (51.95%) | 453 (46.75%) | |
| Skin color | 0.0005 | ||
| Dark/medium | 926 (8.15%) | 65 (6.71%) | |
| Fair | 4467 (39.34%) | 442 (45.61%) | |
| Unknown | 5936 (52.51%) | 462 (47.68%) |
ALM, acral lentiginous melanoma; NM, nodular melanoma; SD, standard deviation.
*
P values were obtained after excluding unknown or missing data.