Table 1.
Selected characteristics among Non-Hispanic white early-onset BCC cases and control (n=759)
| Characteristic | Cases, n (%) (n=376) |
Controls, n (%) (n=383) |
P-value1 |
|---|---|---|---|
| Age (y), median (IQR) | 36.3 (33.2–38.5) | 36.6 (32.6–38.5) | 0.864 |
| Female | 256 (68.1) | 270 (70.5) | 0.472 |
| Body site of skin biopsy | <0.001 | ||
| Head | 204 (54.3) | 161 (42.1) | |
| Extremity | 72 (19.2) | 125 (32.6) | |
| Trunk | 100 (26.6) | 97 (25.3) | |
| Education | <0.010 | ||
| ≤ Some college | 105 (28.0) | 143 (37.5) | |
| College graduate | 112 (29.9) | 111 (29.1) | |
| ≥Some graduate school | 158 (42.1) | 127 (33.4) | |
| Hair color | <0.001 | ||
| Black/dark brown | 100 (26.7) | 157 (50.0) | |
| Light brown | 136 (36.3) | 152 (39.7) | |
| Blonde/fair | 100 (26.7) | 63 (16.4) | |
| Red | 39 (10.4) | 11 (2.9) | |
| Skin color (inner upper arm) | <0.001 | ||
| Olive | 15 (4.0) | 74 (19.3) | |
| Fair | 212 (56.4) | 233 (60.9) | |
| Very fair | 149 (39.6) | 76 (19.8) | |
| Skin reaction with first summer sun exposure | <0.001 | ||
| Turn brown, no sunburn | 6 (1.6) | 31 (8.1) | |
| Mild sunburn followed by tan | 142 (37.8) | 196 (51.3) | |
| Painful sunburn peeling | 198 (52.6) | 142 (37.2) | |
| Severe sunburn blistering | 30 (8.0) | 13 (3.4) | |
| Skin reaction with prolonged sun exposure | <0.001 | ||
| Very brown, deeply tanned | 39 (10.4) | 69 (18.0) | |
| Moderately tanned | 168 (44.7) | 220 (57.5) | |
| Mildly tanned peeling tendency | 123 (32.7) | 76 (19.8) | |
| Freckled, no suntan | 46 (12.2) | 18 (4.7) | |
| Moles ≥ 5 mm on back (n), median (IQR) | 1 (0–3) | 0 (0–2) | 0.005 |
| MC1R nonsynonymous variants | <0.001 | ||
| 0 | 65 (17.3) | 131 (34.2) | |
| 1 | 173 (46.0) | 175 (45.7) | |
| ≥ 2 | 138 (36.7) | 77 (20.1) | |
| Outdoor sun exposure in warm months (h), mean ± SD | 8946 ± 3426 | 8286 ± 3231 | 0.0112 |
| Sunburns (n), median (IQR) | 6 (1–16) | 3 (1–9) | <0.001 |
| Family history of skin cancer | |||
| Family history of non-melanoma skin cancer | 234 (62.2) | 129 (33.7) | <0.001 |
| Family history of melanoma | 46 (12.2) | 34 (8.9) | 0.132 |
IQR, Interquartile range; MC1R, melanocortin 1 receptor gene.
1
X2 for categorical variables, Wilcoxon rank sum for continuous variables
2
t Test