Table 1. The age-standardized characteristics of skin cancer risk factors by frequency of tanning bed use in the Nurses’ Health Study II in 1991
|
Indoor tanning bed use during high school/college (n=75,882)
|
Indoor tanning bed use at 25-35 years (n=75,885)
|
|
None (n=68,805; 90.7%)
|
1-2 (n=3,231; 4.3%)
|
3-5 (n=1,591; 2.1%)
|
6+ (n=2,255; 3.0%)
|
None (n=60,738; 80.0%)
|
1-2 (n=6,095; 8.0%)
|
3-5 (n=3,223; 4.2%)
|
6+ (n=5,829; 7.7%)
|
Age (years), mean (SD)*
|
36.5 (4.6)
|
34.5 (4.9)
|
34.0 (5.0)
|
33.3 (4.9)
|
36.7 (4.6)
|
34.9 (4.7)
|
34.4 (4.6)
|
33.9 (4.6)
|
Hair color
|
|
|
|
|
|
|
|
|
Red hair, %
|
3.9
|
2.9
|
4.2
|
2.8
|
4.1
|
3.3
|
3.1
|
3.0
|
Blonde hair, %
|
16.3
|
18.1
|
17.9
|
19.1
|
16.2
|
17.3
|
18.7
|
17.8
|
Light brown hair, %
|
39.8
|
40.2
|
36.5
|
40.1
|
39.5
|
40.5
|
39.8
|
41.8
|
Dark brown hair, %
|
38.5
|
37.7
|
40.6
|
37.0
|
38.9
|
37.6
|
37.3
|
36.1
|
Black hair, %
|
1.4
|
1.1
|
0.7
|
1.0
|
1.4
|
1.3
|
1.1
|
1.3
|
Family history of melanoma, %
|
4.3
|
4.8
|
6.2
|
5.7
|
4.4
|
4.5
|
3.8
|
4.4
|
Number of blistering sunburns between age 15-20 5+, %
|
9.8
|
11.2
|
12.4
|
15.3
|
10.0
|
9.7
|
10.8
|
10.5
|
Number of moles (> 3mm) on lower extremity 5+, %
|
21.9
|
24.9
|
24.8
|
24.8
|
21.8
|
23.2
|
22.5
|
23.6
|
Painful burn or blisters reaction as a child or adolescent, %
|
24.6
|
21.8
|
20.2
|
20.1
|
25.5
|
20.4
|
18.7
|
17.3
|
UV exposure (mW/m2), mean (SD)
|
185.7 (23.7)
|
186.8 (25.3)
|
185.3 (24.2)
|
186.1 (24.8)
|
186.1 (24.1)
|
184.5 (22.6)
|
184.9 (22.8)
|
184.1 (21.9)
|
Current smoking, %
|
11.4
|
12.8
|
12.1
|
14.0
|
10.6
|
13.3
|
13.8
|
18.4
|
Body Mass Index (kg/m2), mean (SD)
|
24.6 (5.3)
|
24.1 (5.1)
|
24.1 (4.8)
|
23.9 (4.7)
|
24.6 (5.4)
|
23.9 (4.7)
|
24.1 (4.8)
|
24.2 (5.0)
|
Physical activity (metabolic equivalent hours per week), mean (SD)
|
20.5 (26.1)
|
21.3 (27.0)
|
23.0 (28.8)
|
23.5 (33.7)
|
20.2 (25.8)
|
21.7 (26.6)
|
24.7 (30.9)
|
23.7 (29.9)
|
Values are means (standard deviation; SD) for continuous variables, percentages for categorical variables, and are standardized to the age distribution of the study population.
Ultraviolet: UV
*Value is not age adjusted
Table 2. Multivariable-adjusteda HRs for basal cell carcinoma (BCC), squamous cell carcinoma (SCC), and melanoma by cumulative average ultraviolet (UV) exposure during follow-up, number of blistering sunburns between ages 15-20, and indoor tanning bed use in the Nurses' Health Study II (1991-2011)
|
BCC
|
SCC
|
Melanoma
|
Quintile [Q] of UV exposure
|
Cases,
No.
|
HR (95% CI)
|
Cases,
No.
|
HR (95% CI)
|
Cases,
No.
|
HR (95% CI)
|
Q1 (<168.52 mW/m2)
|
1205
|
1 (reference)
|
90
|
1 (reference)
|
95
|
1 (reference)
|
Q2 (168.52-174.68 mW/m2)
|
1399
|
1.20 (1.11, 1.29)
|
84
|
0.94 (0.70, 1.27)
|
88
|
0.96 (0.72, 1.28)
|
Q3 (174.68-181.78 mW/m2)
|
1461
|
1.24 (1.15, 1.34)
|
106
|
1.18 (0.89, 1.56)
|
77
|
0.85 (0.63, 1.15)
|
Q4 (181.78-206.15 mW/m2)
|
1568
|
1.37 (1.27, 1.48)
|
108
|
1.27 (0.96, 1.68)
|
89
|
0.98 (0.73, 1.31)
|
Q5 (>206.15 mW/m2)
|
1699
|
1.53 (1.42, 1.65)
|
138
|
1.61 (1.23, 2.11)
|
94
|
1.04 (0.78, 1.38)
|
Ptrend
|
|
< 0.0001
|
|
< 0.0001
|
|
0.46
|
Number of blistering sunburns between ages 15-20
|
|
|
|
|
|
|
None
|
1852
|
1 (reference)
|
130
|
1 (reference)
|
104
|
1 (reference)
|
1-2
|
2795
|
1.18 (1.11,1.25)
|
205
|
1.22 (0.97,1.52)
|
169
|
1.26 (0.98,1.61)
|
3-4
|
1570
|
1.41 (1.31,1.51)
|
106
|
1.29 (0.99,1.68)
|
98
|
1.55 (1.17,2.07)
|
≥ 5
|
1094
|
1.58 (1.45,1.70)
|
81
|
1.55 (1.16,2.08)
|
69
|
1.76 (1.26, 2.40)
|
Ptrend
|
|
< 0.0001
|
|
0.004
|
|
0.0002
|
Indoor tanning bed use during high school/college
|
|
|
|
|
|
|
None
|
5593
|
1 (reference)
|
436
|
1 (reference)
|
362
|
1 (reference)
|
1-2
|
294
|
1.19 (1.05, 1.34)
|
17
|
0.99 (0.61, 1.60)
|
24
|
1.40 (0.92, 2.13)
|
3-5
|
135
|
1.12 (0.94, 1.33)
|
14
|
1.72 (1.01, 2.94)
|
9
|
1.07 (0.55, 2.08)
|
≥ 6
|
273
|
1.70 (1.50, 1.92)
|
14
|
1.32 (0.77, 2.25)
|
10
|
0.86 (0.45, 1.61)
|
Ptrend
|
|
<0.0001
|
|
0.10
|
|
0.85
|
Indoor tanning bed use during ages 25-35
|
|
|
|
|
|
|
None
|
4929
|
1 (reference)
|
370
|
1 (reference)
|
324
|
1 (reference)
|
1-2
|
539
|
1.17 (1.07, 1.28)
|
45
|
1.43 (1.04, 1.95)
|
29
|
0.90 (0.61, 1.32)
|
3-5
|
299
|
1.26 (1.12, 1.42)
|
23
|
1.49 (0.98, 2.28)
|
16
|
0.97 (0.59, 1.61)
|
≥ 6
|
539
|
1.33 (1.22, 1.46)
|
42
|
1.62 (1.17, 2.24)
|
37
|
1.27 (0.90, 1.80)
|
Ptrend
|
|
<0.0001
|
|
0.0004
|
|
0.28
|
HR: hazard ratio, 95% CI: 95% confidence interval
aAdjusted for age at diagnosis, natural hair color (red, blonde, light brown, dark brown or black), family history of melanoma (yes or no), number of blistering sunburns between age 15 and 20 (none, 1-2, 3-4, or ≥ 5), number of moles on legs (none, 1–2, 3–4, or ≥ 5), sunburn reaction as a child/adolescent (none/some redness, burn, or painful burn/blisters), smoking status (no, past < 10 pack-year, past 10-19 pack-year, past 20+ pack-year, currently smoking), BMI (<18.5, 18.5–24.9, 25–29.9, 30–34.9, and ≥ 35 kg/m2), and physical activity (quintiles, metabolic equivalent hours/week).
Table 3. Multivariable-adjusteda HRs for basal cell carcinoma (BCC), squamous cell carcinoma (SCC), and melanoma by joint effect between cumulative average ultraviolet (UV) exposure during follow-upb and indoor tanning bed use in the Nurses' Health Study II (1991-2011)
|
BCC
|
SCC
|
Melanoma
|
Joint effects
|
Cases, No.
|
HR (95% CI)
|
Cases, No.
|
HR (95% CI)
|
Cases, No.
|
HR (95% CI)
|
Cumulative average UV and tanning bed use during high school/college
|
|
|
|
|
|
|
Low UV & No tanning bed use
|
2296
|
1 (reference)
|
165
|
1 (reference)
|
161
|
1 (reference)
|
Low UV & Used tanning bed
|
314
|
1.49 (1.32, 1.68)
|
18
|
1.37 (0.84, 2.24)
|
23
|
1.42 (0.91, 2.21)
|
High UV & No tanning bed use
|
3297
|
1.27 (1.20, 1.34)
|
271
|
1.40 (1.15, 1.70)
|
201
|
1.10 (0.89, 1.36)
|
High UV & Used tanning bed
|
388
|
1.53 (1.37, 1.71)
|
27
|
1.64 (1.08, 2.47)
|
20
|
1.06 (0.66, 1.69)
|
Pinteraction
|
|
0.01
|
|
0.63
|
|
0.23
|
|
|
|
|
|
|
|
Cumulative average UV and tanning bed use during ages 25-35
|
|
|
|
|
|
|
Low UV & No tanning bed use
|
2020
|
1 (reference)
|
138
|
1 (reference)
|
144
|
1 (reference)
|
Low UV & Used tanning bed
|
598
|
1.27 (1.16, 1.40)
|
45
|
1.60 (1.14, 2.24)
|
41
|
1.11 (0.78, 1.58)
|
High UV & No tanning bed use
|
2909
|
1.25 (1.18, 1.32)
|
232
|
1.41 (1.14, 1.74)
|
180
|
1.08 (0.86, 1.34)
|
High UV & Used tanning bed
|
779
|
1.54 (1.42, 1.68)
|
65
|
2.07 (1.53, 2.79)
|
41
|
1.08 (0.76. 1.54)
|
Pinteraction
|
|
0.65
|
|
0.71
|
|
0.69
|
HR: hazard ratio, 95% CI: 95% confidence interval
aAdjusted for age at diagnosis, natural hair color (red, blonde, light brown, dark brown or black), family history of melanoma (yes or no), number of blistering sunburns between age 15 and 20 (none, 1-2, 3-4, or ≥ 5), number of moles on legs (none, 1–2, 3–4, or ≥ 5), sunburn reaction as a child/adolescent (none/some redness, burn, or painful burn/blisters), smoking status (no, past < 10 pack-year, past 10-19 pack-year, past 20+ pack-year, currently smoking), BMI (<18.5, 18.5–24.9, 25–29.9, 30–34.9, and ≥ 35 kg/m2), and physical activity (quintiles, metabolic equivalent hours/week).
bThe median value (179 mW/m2) was used a cut off for high versus low UV
Table 4. Multivariable-adjusteda HRs for basal cell carcinoma (BCC), squamous cell carcinoma (SCC), and melanoma by joint effect between history of severe sunburnb and indoor tanning use in the Nurses' Health Study II (1991-2011)
|
BCC
|
SCC
|
Melanoma
|
Joint effects
|
Cases, No.
|
HR (95% CI)
|
Cases, No.
|
HR (95% CI)
|
Cases, No.
|
HR (95% CI)
|
History of severe sunburn and tanning bed use during high school/college
|
|
|
|
|
|
|
No severe sunburn & No tanning bed use
|
1471
|
1 (reference)
|
111
|
1 (reference)
|
81
|
1 (reference)
|
No severe sunburn & Used tanning bed
|
169
|
1.59 (1.36, 1.87)
|
8
|
1.15 (0.56, 2.36)
|
15
|
2.33 (1.34, 4.06)
|
Severe sunburn & No tanning bed use
|
4113
|
1.27 (1.20, 1.35)
|
322
|
1.29 (1.03, 1.61)
|
281
|
1.58 (1.22, 2.03)
|
Severe sunburn & Used tanning bed
|
532
|
1.62 (1.47, 1.79)
|
37
|
1.65 (1.13, 2.41)
|
27
|
1.40 (0.90, 2.18)
|
Pinteraction
|
|
0.02
|
|
0.79
|
|
0.01
|
|
|
|
|
|
|
|
History of severe sunburn and tanning bed use during ages 25-35
|
|
|
|
|
|
|
No severe sunburn & No tanning bed use
|
1282
|
1 (reference)
|
88
|
1 (reference)
|
74
|
1 (reference)
|
No severe sunburn & Used tanning bed
|
358
|
1.43 (1.27, 1.61)
|
31
|
2.04 (1.35, 3.08)
|
22
|
1.41 (0.87, 2.28)
|
Severe sunburn & No tanning bed use
|
3640
|
1.29 (1.21, 1.37)
|
281
|
1.41 (1.11, 1.81)
|
250
|
1.53 (1.18, 2.00)
|
Severe sunburn & Used tanning bed
|
1016
|
1.56 (1.43, 1.69)
|
77
|
1.88 (1.38, 2.57)
|
59
|
1.48 (1.04, 2.09)
|
Pinteraction
|
|
0.02
|
|
0.08
|
|
0.18
|
HR: hazard ratio, 95% CI: 95% confidence interval
aAdjusted for age, natural hair color (red, blonde, light brown, dark brown or black), family history of melanoma (yes or no), number of moles on legs (none, 1–2, 3–4, or ≥ 5), sunburn reaction as a child/adolescent (none/some redness, burn, or painful burn/blisters), smoking status (no, past < 10 pack-year, past 10-19 pack-year, past 20+ pack-year, currently smoking), BMI (<18.5, 18.5–24.9, 25–29.9, 30–34.9, and ≥ 35 kg/m2), and physical activity (quintiles, metabolic equivalent hours/week).
bSevere sunburn: ≥ 1 blistering sunburns between age 15-20, no severe sunburn: no bli