Table 2.
Phenotypic characteristics, reported sunburn and melanoma risk
| Risk factor | Controls | Cases | OR* (95% CI) | OR^ (95% CI) |
|---|---|---|---|---|
| Eye color | ||||
| Brown | 77 (15%) | 106 (11%) | 1 | 1 |
| Green/Hazel | 196 (39%) | 326 (34%) | 1.24 (0.87-1.77) | 1.24 (0.87-1.78) |
| Blue/Grey | 233 (46%) | 514 (54%) | 1.71 (1.21-2.41) | 1.68 (1.18-2.37) |
| Natural hair color | ||||
| Black/Brown | 407 (81%) | 623 (67%) | 1 | 1 |
| Blond | 68 (13%) | 182 (20%) | 1.76 (1.29-2.41) | 1.80 (1.31-2.47) |
| Red | 29 (6%) | 121 (13%) | 2.85 (1.85-4.41) | 2.97 (1.91-4.64) |
| Self reported freckles as child | ||||
| None | 193 (38%) | 223 (25%) | 1 | 1 |
| Very few | 131 (26%) | 271 (30%) | 1.58 (1.18-2.12) | 1.55 (1.15-2.09) |
| Few/Some | 161 (31%) | 321 (36%) | 1.51 (1.14-2.01) | 1.48 (1.11-1.98) |
| Many | 27 (5%) | 82 (9%) | 2.53 (1.53-4.16) | 2.64 (1.57-4.43) |
| Reported skin color inside upper arm | ||||
| Olive/Brown | 60 (12%) | 71 (8%) | 1 | 1 |
| Fair | 365 (72%) | 569 (61%) | 1.29 (0.89-1.88) | 1.34 (0.92-1.95) |
| Very fair | 79 (16%) | 286 (31%) | 2.83 (1.84-4.36) | 2.95 (1.91-4.58) |
| Ability to tan | ||||
| Go very brown and deeply tanned | 77 (15%) | 103 (11%) | 1 | 1 |
| Get moderately tanned | 259 (52%) | 379 (41%) | 1.31 (0.90-1.91) | 1.19 (0.84-1.68) |
| Get mildly or occasionally tanned | 121 (24%) | 331 (36%) | 1.88 (1.27-2.80) | 2.23 (1.53-3.26) |
| Get no suntan at all or only freckled | 42 (8%) | 110 (12%) | 2.24 (1.06-4.76) | 2.06 (1.28-3.33) |
| Propensity to burn | ||||
| Go brown without any sunburn | 62 (12%) | 77 (8%) | 1 | 1 |
| Get mildly burnt followed by some tanning |
281 (56%) | 463 (50%) | 1.14 (0.81-1.60) | 1.37 (0.94-2.01) |
| Have a painful sunburn for a few days followed by peeling |
145 (29%) | 347 (38%) | 2.13 (1.47-3.09) | 1.96 (1.31-2.94) |
| Get a severe sunburn with blistering | 12 (2%) | 34 (4%) | 2.14 (1.33-3.42) | 2.22 (1.04-4.75) |
| Sun sensitivity score § | ||||
| Quartile 4 | 182 (35%) | 197 (21%) | 1 | 1 |
| Quartile 3 | 139 (27%) | 216 (23%) | 1.38 (1.02-1.86) | 1.40 (1.03-1.90) |
| Quartile 2 | 119 (23%) | 249 (26%) | 1.85 (1.36-2.51) | 1.89 (1.39-2.59) |
| Quartile 1 | 73 (14%) | 298 (31%) | 3.66 (2.62-5.11) | 3.62 (2.57-5.10) |
| Sunburn under age 20 | ||||
| Never | 347 (73%) | 561 (65%) | 1 | 1 |
| At least once | 130 (27%) | 297 (35%) | 1.24 (0.96-1.59) | 1.24 (0.95-1.60) |
| Sunburn at or after age 20 | ||||
| Never | 315 (68%) | 511 (58%) | 1 | 1 |
| At least once | 147 (32%) | 365 (42%) | 1.56 (1.23-1.99) | 1.56 (1.22-2.00) |
§
Sun sensitivity score was derived by factor analysis using hair color, eye color, self reported freckle as child, propensity to burn, ability to tan and skin color of inside upper arm with average factor loading being 0.44, 0.21, 0.38, 0.56, 0.66 and 0.61, respectively.
*
ORs are corrected for age, sex and Townsend (deprivation) score.
^
ORs are corrected for age, sex, Townsend (deprivation) score and weekend sun exposure at warmer month.
Total numbers of cases and controls may vary due to missing data.