Role of MC1R on MM risk after stratification on clinical risk factors and UV exposure parameters
| Risk factor | Allele | *Cases | *Controls | p | OR | 95%CI | |
|---|---|---|---|---|---|---|---|
| Wt, wild type allele; V, variant alleles. | |||||||
| *Results are indicated both by percentage of patients, and by number of patients (in parentheses). | |||||||
| Odds ratios (OR) compare Wt/V (heterozygotes) and V/V (two functional variants) with Wt/Wt. | |||||||
| CI, 95% confidence interval. | |||||||
| Skin type | I/II | Total | 49 | 43 | – | – | – |
| Wt/Wt | 22 (11) | 67 (29) | – | Reference | – | ||
| Wt/V | 51 (25) | 23 (10) | 0.0001 | 6.59 | 2.40–18.09 | ||
| V/V | 27 (13) | 9 (4) | 0.0006 | 8.57 | 2.29–32.01 | ||
| III/IV | Total | 52 | 62 | – | – | – | |
| Wt/Wt | 42 (22) | 69 (43) | – | Reference | – | ||
| Wt/V | 52 (27) | 29 (18) | 0.007 | 2.93 | 1.33–6.43 | ||
| V/V | 6 (3) | 2 (1) | 0.13$ | 5.86 | 0.43–314.79 | ||
| Skin colour | Light/medium | Total | 93 | 76 | – | – | – |
| Wt/Wt | 30 (28) | 71 (54) | – | Reference | – | ||
| Wt/V | 53 (49) | 24 (18) | <0.0001 | 5.25 | 2.59–10.65 | ||
| V/V | 17 (16) | 5 (4) | 0.0002 | 7.71 | 2.35–25.28 | ||
| Eye colour | Light | Total | 52 | 34 | – | – | – |
| Wt/Wt | 37 (19) | 79 (27) | – | Reference | – | ||
| Wt/V | 42 (22) | 12 (4) | 0.0004 | 7.81 | 2.32–26.38 | ||
| V/V | 21 (11) | 9 (3) | 0.015 | 5.21 | 1.28–21.24 | ||
| Dark | Total | 45 | 71 | – | – | – | |
| Wt/Wt | 31 (14) | 63 (45) | – | Reference | – | ||
| Wt/V | 58 (26) | 34 (24) | 0.002 | 3.48 | 1.54–7.88 | ||
| V/V | 11 (5) | 3 (2) | 0.018$ | 8.04 | 1.12–89.57 | ||
| Hair colour | Red/blond/light brown | Total | 47 | 29 | – | – | – |
| Wt/Wt | 28 (13) | 66 (19) | – | Reference | – | ||
| Wt/V | 45 (21) | 21 (6) | 0.004 | 5.12 | 1.62–16.14 | ||
| V/V | 28 (13) | 14 (4) | 0.017 | 4.75 | 1.26–17.86 | ||
| Dark brown/black | Total | 50 | 76 | – | – | – | |
| Wt/Wt | 40 (20) | 70 (53) | – | Reference | – | ||
| Wt/V | 54 (27) | 29 (22) | 0.002 | 3.25 | 1.52–6.97 | ||
| V/V | 6 (3) | 1 (1) | 0.077$ | 7.95 | 0.58–424.97 | ||
| Naevus count | ⩽50 | Total | 53 | 98 | – | – | – |
| Wt/Wt | 30 (16) | 68 (67) | – | Reference | – | ||
| Wt/V | 53 (28) | 28 (27) | <0.0001 | 4.34 | 2.03–9.28 | ||
| V/V | 17 (9) | 4 (4) | 0.0005$ | 9.42 | 2.21–45.91 | ||
| Severe sunburns | No | Total | 49 | 68 | – | – | – |
| at <15 years of age | Wt/Wt | 35 (17) | 72 (41) | – | Reference | – | |
| Wt/V | 55 (27) | 27 (18) | 0.0018 | 3.62 | 1.59–8.23 | ||
| V/V | 10 (5) | 1 (1) | 0.016$ | 12.06 | 1.17–583.78 | ||
| Yes | Total | 49 | 37 | – | – | – | |
| Wt/Wt | 31 (15) | 62 (23) | – | Reference | – | ||
| Wt/V | 47 (23) | 27 (10) | 0.011 | 3.53 | 1.31–9.46 | ||
| V/V | 22 (11) | 11 (4) | 0.026 | 4.22 | 1.13–15.72 | ||
| Severe sunburns at | No | Total | 41 | 41 | – | – | – |
| at >15 years of age | Wt/Wt | 34 (14) | 71 (41) | – | Reference | – | |
| Wt/V | 56 (23) | 26 (15) | 0.0007 | 4.49 | 1.85–10.93 | ||
| V/V | 10 (4) | 3 (2) | 0.06$ | 5.86 | 0.72–68.94 | ||
| Yes | Total | 57 | 47 | – | – | – | |
| Wt/Wt | 32 (18) | 66 (31) | – | Reference | – | ||
| Wt/V | 47 (27) | 28 (13) | 0.0004 | 3.58 | 1.48–8.63 | ||
| V/V | 21 (12) | 6 (3) | 0.0036 | 6.89 | 1.71–27.72 | ||
| Holidays exposure at | High | Total | 86 | 84 | – | – | – |
| at <15 years of age | Wt/Wt | 36 (31) | 68 (57) | – | Reference | – | |
| Wt/V | 48 (41) | 26 (22) | 0.0003 | 3.43 | 1.74–6.75 | ||
| V/V | 16 (14) | 6 (5) | 0.002 | 5.15 | 1.70–15.64 | ||
| Holidays exposure at | High | Total | 86 | 83 | – | – | – |
| at >15 years of age | Wt/Wt | 35 (30) | 71 (59) | – | Reference | – | |
| Wt/V | 50 (43) | 25 (21) | <0.0001 | 4.03 | 2.04–7.97 | ||
| V/V | 15 (13) | 4 (3) | 0.0004 | 8.52 | 2.25–32.23 | ||