Table 4.
Patient demographics and tumor characteristics—SEER cohort.
| Descriptor | Class 1A (n = 4526) | Class 1B/2A (n = 865) | Class 2B (n = 260) | Combined (n = 5651) |
|---|---|---|---|---|
| Age (years), median (Range) | 60 (18–90+) | 64 (18–90+) | 65 (22–90+) | 61 (18–90+) |
| Sex | ||||
| Female | 2089 (46.2%) | 383 (44.3%) | 96 (36.9%) | 2568 (45.4%) |
| Male | 2437 (53.8%) | 482 (55.7%) | 164 (63.1%) | 3083 (54.6%) |
| Tumor Location | ||||
| Extremity | 2054 (45.3%) | 430 (49.7%) | 141 (54.2%) | 2625 (46.5%) |
| Head and neck | 799 (17.6%) | 209 (24.2%) | 59 (22.7%) | 1067 (18.9%) |
| Trunk | 1648 (36.3%) | 222 (25.7%) | 60 (23.1%) | 1930 (34.2%) |
| Not specified | 25 (0.6%) | 4 (0.5%) | 0 (0.0%) | 29 (0.5%) |
| Breslow thickness (mm), median (Range) | 0.6 (0–2.0) | 1.1 (0.1–2.0) | 1.1 (0.1–2.0) | 0.7 (0–2.0) |
| Ulceration | ||||
| No | 3745 (82.7%) | 667 (77.1%) | 168 (64.6%) | 4580 (81.0%) |
| Yes | 92 (2.0%) | 39 (4.5%) | 30 (11.5%) | 161 (2.8%) |
| Unknown | 689 (15.2%) | 159 (18.4%) | 62 (23.8%) | 910 (16.1%) |
| Mitotic rate (1/mm2), median (Range) | 0 (0–11) | 1 (0–11) | 1 (0–11) | 0 (0–11) |
| Melanoma-specific death | ||||
| No | 4504 (99.5%) | 860 (99.4%) | 250 (96.2%) | 5614 (99.3%) |
| Yes | 22 (0.5%) | 5 (0.6%) | 10 (3.8%) | 37 (0.7%) |
| T-stage | ||||
| T1a | 2850 (63.0%) | 199 (23.0%) | 71 (27.3%) | 3120 (55.2%) |
| T1b | 936 (20.7%) | 216 (25.0%) | 52 (20.0%) | 1204 (21.3%) |
| T2a | 740 (16.3%) | 450 (52.0%) | 137 (52.7%) | 1327 (23.5%) |
| AJCC 8th edition * | ||||
| Stage IA | 3606 (79.7%) | 375 (43.4%) | 116 (44.6%) | 4097 (72.5%) |
| Stage IB | 920 (20.3%) | 490 (56.6%) | 144 (55.4%) | 1554 (27.5%) |
Abbreviation: AJCC, American Joint Committee on Cancer; * AJCC stage was determined using Breslow thickness and ulceration status.