TABLE 1.
Characteristics of Superficial Spreading Melanoma and Nodular Melanoma Within Each Time Period and Over Time
| Characteristic | Years 1972-1982
|
Years 2002-2007
|
Changes Between 1972-1982 and 2002-2007
|
|||||
|---|---|---|---|---|---|---|---|---|
| SSM, No. (%) | NM, No. (%) | P | SSM, No. (%) | NM, No. (%) | P | SSM, P | NM, P | |
| Age (y, median) | 51 | 51 | .69 | 56 | 63 | .001 | <.0001 | <.0001 |
| Sex (men, women) | 380 (48), 415 (52) | 66 (52), 60 (48) | .33 | 168 (56), 131 (44) | 74 (59), 51 (41) | .57 | .01 | .28 |
| Thickness (mm, median) | 1.1 | 3.2 | <.0001 | 0.6 | 2.4 | <.0001 | <.0001 | .10 |
| Clark’s level | ||||||||
| I | 32 (4.0) | 0 (0.0) | <.0001 | 0 (0.0) | 0 (0.0) | <.0001 | .02* | .008* |
| II | 235 (29.1) | 0 (0.0) | 119 (40.2) | 1 (0.9) | ||||
| III | 227 (28.1) | 21 (17.1) | 74 (25.0) | 6 (5.2) | ||||
| IV | 293 (36.2) | 89 (72.4) | 102 (34.5) | 93 (80.2) | ||||
| V | 22 (2.7) | 13 (10.6) | 1 (0.3) | 16 (13.8) | ||||
| Ulceration present | 145 (18.2) | 58 (47.2) | <.0001 | 17 (5.7) | 50 (40.7) | <.0001 | <.0001 | .30 |
| Regression present | 166 (26.2) | 4 (5.8) | .0002 | 96 (33.5) | 30 (27.3) | .24 | .02 | .0004 |
| Mitoses (per mm2, median) | 1.0 | 2.5 | <.0001 | |||||
| None | 86 (31.6) | 5 (4.8) | <.0001 | |||||
| Few (≤2 mitoses/HPF) | 132 (48.5) | 27 (25.7) | ||||||
| Moderate (3-5 mitoses/HPF) | 27 (9.9) | 23 (21.9) | ||||||
| Many (>5 mitoses/HPF) | 27 (9.9) | 50 (47.6) | ||||||
| Stage | ||||||||
| I | 524 (68.8) | 27 (22.0) | <.0001 | 264 (86.0) | 43 (33.9) | <.0001 | <.0001 | .05 |
| II | 163 (21.4) | 61 (49.6) | 28 (9.1) | 56 (44.1) | <.0001 | .46 | ||
| III | 71 (9.3) | 33 (26.8) | 15 (4.9) | 28 (22.1) | .02 | .46 | ||
| IV | 4 (0.5) | 2 (1.6) | 0 (0.0) | 0 (0.0) | .48 | .46 | ||
SSM indicates superficial spreading melanoma; NM, nodular melanoma; HPF, high-power field.
*
Denotes the change over time in the proportion of melanomas presenting as Clark level IV or V.