Table 1.
Characteristics of 2914 Primary Melanomas from 2387 Patients Scored for Histopathologic Pigmentation in the GEM Study
| Incident Primary Melanoma | Prior Primary Melanoma | |
|---|---|---|
| Characteristic | (n=2387)a | (n=527)a |
| Sex | ||
| Male | 1322 (55.4) | 354 (67.2) |
| Female | 1065 (44.6) | 173 (32.8) |
| Age at diagnosis, y | ||
| Mean (±SD) | 58.3 ± 16.1 | 65.9 ± 12.9 |
| < 50 | 712 (29.8) | 62 (11.8) |
| 50–69 | 966 (40.5) | 222 (42.1) |
| ≥ 70 | 709 (29.7) | 243 (46.1) |
| Race/Ethnicity | ||
| Caucasian | 2380 (99.7) | 526 (99.8) |
| Non-Caucasian | 7 (0.3) | 1 (0.2) |
| Country | ||
| Australia (New South Wales & Tasmania) | 1096 (45.9) | 394 (74.8) |
| Canada (British Columbia & Ontario) | 547 (22.9) | 76 (14.4) |
| Italy (Torino) | 75 (3.1) | 2 (0.4) |
| United States (NC, NJ, MI, and CA) | 669 (28.0) | 55 (10.4) |
| Histopathologic pigmentation | ||
| Pigmented | 2209 (92.5) | 495 (93.9) |
| Amelanotic | 178 (7.5) | 32 (6.1) |
| Histologic subtype | ||
| Superficial Spreading | 1551 (65.0) | 353 (67.0) |
| Nodular | 182 (7.6) | 40 (7.6) |
| Lentigo maligna | 286 (12.0) | 87 (16.5) |
| In-situ | 161 (6.7) | 0 (0.0) |
| Unclassified/otherb | 207 (8.7) | 47 (8.9) |
| Anatomic Site | ||
| Head, neck | 437 (18.3) | 84 (15.9) |
| Trunk, pelvis | 1040 (43.6) | 248 (47.1) |
| Upper extremities | 424 (17.8) | 94 (17.8) |
| Lower extremities | 486 (20.4) | 101 (19.2) |
| Breslow thickness, mmc | (n=2,380) | (n=525) |
| Median (IQR), mm | 0.6 (0.8) | 0.7 (0.7) |
| In-situ | 167 (7.0) | 0 (0.0) |
| 0.01 to 1.00 | 1518 (63.8) | 365 (69.5) |
| 1.01 to 2.00 | 405 (17.0) | 95 (18.1) |
| 2.01 to 4.00 | 195 (8.2) | 49 (9.3) |
| >4.00 | 95 (4.0) | 16 (3.1) |
Abbreviations: GEM = Genes, Environment, and Melanoma; IQR = interquartile range; SD = standard deviation.
a
Data are given as number (percentage) of melanomas.
b
Other includes acral lentiginous, spindle cell, nevoid, and Spitzoid melanomas.
c
Counts do not sum to the total number of study subjects due to missing data.