Table 1 Characteristics of the cases and their matched controls.
Melanoma cases, n = 183 | Controls, n = 183 | |
|---|---|---|
Age at recruitment (years), mean (SD) | 48.0 (6.55) | 47.9 (6.53) |
Birth cohort, n (%) | ||
1943–1947 | 73 (39.9) | 73 (39.9) |
1948–1952 | 70 (38.3) | 70 (38.3) |
1953–1957 | 40 (21.9) | 40 (21.9) |
Recruitment year, n (%) | ||
1991–1992 | 80 (43.7) | 81 (44.3) |
1996–1997 | 29 (15.8) | 29 (15.8) |
Age at blood sample (years), mean (SD) | 55.7 (4.24) | 55.7 (4.24) |
Time in freezer (years), mean (SD) | 11.23 (0.97) | 11.21 (0.95) |
Education (years), n (%) | ||
≤ 10 | 43 (23.5) | 54 (29.5) |
11–13 | 57 (31.1) | 55 (30.1) |
≥ 14 | 78 (42.6) | 67 (36.6) |
Missing | 5 (2.7) | 7 (3.8) |
Smoking, n (%) | ||
Non-smoker | 77 (42.1) | 61 (33.3) |
Former | 71 (38.8) | 73 (39.9) |
Current | 33 (18.0) | 46 (25.1) |
Missing | 2 (1.1) | 3 (1.6) |
Hair color, n (%) | ||
Black/dark brown | 23 (12.6) | 33 (18.0) |
Brown | 53 (29.0) | 75 (41.0) |
Blond/yellow | 82 (44.8) | 60 (32.8) |
Red | 15 (8.2) | 5 (2.7) |
Missing | 10 (5.5) | 10 (5.5) |
Freckling when sunbathing, n (%) | ||
Yes | 78 (42.6) | 67 (36.6) |
No | 103 (56.3) | 111 (60.7) |
Missing | 2 (1.1) | 5 (2.7) |
No. of large asymmetric nevi on legs, n (%) | ||
0 | 136 (74.3) | 147 (80.3) |
1 | 11 (6.0) | 11 (6.0) |
≥ 2 | 20 (10.9) | 8 (4.4) |
Missing | 16 (8.7) | 17 (9.3) |
Residential ambient UVR | ||
Low (northern Norway) | 23 (12.6) | 33 (18.0) |
Medium–low (central Norway) | 27 (14.8) | 22 (12.0) |
Medium (south-west Norway) | 37 (20.2) | 26 (14.2) |
Highest (south-east Norway) | 96 (52.5) | 102 (55.7) |
Missing | 0 | 0 |
Lifetime no. of sunburnsa | ||
0 | 15 (8.2) | 24 (13.1) |
1–20 | 39 (21.3) | 42 (23.0) |
21–30 | 34 (18.6) | 24 (13.1) |
31–47 | 45 (24.6) | 45 (24.6) |
48–58 | 26 (14.2) | 21 (11.5) |
59+ | 20 (10.9) | 20 (10.9) |
Missing | 4 (2.2) | 7 (3.8) |
Lifetime no. of sunbathing vacationsa | ||
0 | 14 (7.7) | 14 (7.7) |
1–29 | 45 (24.6) | 44 (24.0) |
30–62 | 32 (17.5) | 44 (24.0) |
63–104 | 39 (21.3) | 41 (22.4) |
105–143 | 21 (11.5) | 16 (8.7) |
144 + | 26 (14.2) | 17 (9.3) |
Missing | 6 (3.3) | 7 (3.8) |
Lifetime no. of indoor tanning sessionsa | ||
0 | 46 (25.1) | 49 (26.8) |
1–14 | 30 (16.4) | 32 (17.5) |
15–24 | 50 (27.3) | 38 (20.8) |
25–120 | 25 (13.7) | 32 (17.5) |
121–418 | 14 (7.7) | 18 (9.8) |
419+ | 17 (9.3) | 14 (7.7) |
Missing | 1 (0.6) | 0 (0) |
Cumulative UVRb | ||
0 | 8 (4.4) | 10 (5.5) |
1 | 15 (8.2) | 18 (9.8) |
2 | 26 (14.2) | 20 (10.9) |
3 | 15 (8.2) | 31 (16.9) |
4 | 31 (16.9) | 26 (14.2) |
5 | 34 (18.6) | 25 (13.7) |
6 | 24 (13.1) | 24 (13.1) |
7 | 15 (8.2) | 15 (8.2) |
8 | 8 (4.4) | 7 (3.8) |
9 | 3 (1.6) | 5 (2.7) |
10 | 4 (2.2) | 2 (1.1) |
Age at diagnosis (years), mean (SD) | 60.2 (4.89) | N/A |
Time from blood sampling to diagnosis (years), mean (SD) | 4.44 (2.53) | N/A |
Tumor thickness (mm), median (IQR) | 0.9 (0.5,1.5) | N/A |
Tumor thickness (mm), n (%) | ||
T1 (≤ 1 mm) | 109 (59.6) | N/A |
T2 (1.01–2.0) | 32 (17.5) | N/A |
T3 (2.01–4.0) | 22 (12.0) | N/A |
T4 (> 4) | 6 (3.3) | N/A |
Missing | 14 (7.7) | N/A |
