Table 4.
Relative Risks (RR) for melanoma in situ (MIS) Among whites and non-whites/multiracials recruited to the Multiethnic Cohort Study, 1993–1996
| Characteristics | whites | Non-whites/Multracials | p-heterogeneityc | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Ca | RR | 95% CIa | RR | 95% CIb | ca | RR | 95% CIa | RR | 95% CIb | ||
| Study Site | |||||||||||
| California | 37 | 1.00 | 1.00 | 33 | 1.00 | 1.00 | |||||
| Hawaii | 300 | 3.13 | (2.20, 4.44) | 2.88 | (2.03, 4.09) | 39 | 1.06 | (0.54, 2.09) | 1.07 | (0.54, 2.12) | |
| P-value | <0.001 | <0.001 | 0.867 | 0.839 | <0.001 | ||||||
| Sex | |||||||||||
| Male | 217 | 1.00 | 1.00 | 40 | 1.00 | 1.00 | |||||
| Female | 120 | 0.56 | (0.45, 0.70) | 0.53 | (0.42, 0.66) | 32 | 0.71 | (0.44, 1.13) | 0.68 | (0.42, 1.08) | |
| P-value | <0.001 | <0.001 | 0.143 | 0.103 | 0.309 | ||||||
| Education | |||||||||||
| ≤ High school | 42 | 1.00 | 1.00 | 37 | 1.00 | 1.00 | |||||
| Some college | 98 | 1.90 | (1.32, 2.73) | 1.68 | (1.16, 2.42) | 22 | 1.18 | (0.68, 2.05) | 1.14 | (0.65, 1.98) | |
| ≥ College | 197 | 2.50 | (1.78, 3.50) | 2.11 | (1.50, 2.97) | 13 | 0.91 | (0.46, 1.78) | 0.84 | (0.43, 1.65) | 0.015 |
| P-trend | <0.001 | <0.001 | 0.906 | 0.724 | |||||||
| Age | |||||||||||
| 1 year increase | 1.04 | (1.03, 1.05) | 1.03 | (1.02, 1.05) | 1.03 | (1.01, 1.06) | 1.03 | (1.00, 1.06) | |||
| P-value | <0.001 | <0.001 | 0.028 | 0.046 | 0.184 | ||||||
| Hair color | |||||||||||
| Black/Medium dark brown | 163 | 1.00 | 1.00 | 60 | 1.00 | 1.00 | |||||
| Light brown | 100 | 1.32 | (1.03, 1.70) | 1.25 | (0.97, 1.60) | 7 | 1.91 | (0.83, 4.38) | 1.77 | (0.77, 4.07) | |
| Blonde | 64 | 1.65 | (1.23, 2.20) | 1.48 | (1.11, 1.98) | 5 | 15.0 | (5.76, 38.9) | 12.4 | (4.64, 33.0) | |
| Red | 10 | 1.20 | (0.64, 2.28) | 0.96 | (0.50, 1.82) | 0 | -- | -- | |||
| P-trend | 0.002 | 0.036 | <0.001 | 0.001 | 0.002 | ||||||
| Eye color | |||||||||||
| Dark (black/dark brown) | 103 | 1.00 | 1.00 | 59 | 1.00 | 1.00 | |||||
| Light (blue, grey, and green) | 234 | 1.40 | (1.11, 1.76) | 1.25 | (0.99, 1.59) | 13 | 4.44 | (2.28, 8.66) | 3.97 | (2.00, 7.88) | |
| P-value | 0.005 | 0.059 | <0.001 | <0.001 | 0.002 | ||||||
| Tanning ability | |||||||||||
| Deeply | 64 | 1.00 | 1.00 | 21 | 1.00 | 1.00 | |||||
| Moderately | 204 | 1.35 | (1.02, 1.78) | 1.25 | (0.94, 1.66) | 36 | 0.95 | (0.55, 1.63) | 0.95 | (0.55, 1.64) | |
| Lightly | 61 | 1.51 | (1.06, 2.15) | 1.26 | (0.88, 1.80) | 15 | 1.52 | (0.77, 2.98) | 1.53 | (0.78, 3.00) | |
| Not at all | 8 | 1.76 | (0.84, 3.69) | 1.39 | (0.66, 2.92) | 0 | -- | ||||
| P-trend | 0.012 | 0.166 | 0.708 | 0.694 | 0.804 | ||||||
| Skin reaction to sunlight | |||||||||||
| No effect, or tans | 45 | 1.00 | 1.00 | 33 | 1.00 | 1.00 | |||||
| Mild burn, then tans | 174 | 1.51 | (1.09, 2.10) | 1.32 | (0.95, 1.84) | 24 | 0.82 | (0.48, 1.39) | 0.79 | (0.46, 1.35) | |
| Severe burns without blistering | 83 | 1.92 | (1.33, 2.76) | 1.51 | (1.04, 2.00) | 12 | 1.76 | (0.90, 3.44) | 1.57 | (0.79, 3.12) | |
| Severe burning with blistering | 35 | 1.69 | (1.08, 2.63) | 1.23 | (0.78, 1.94) | 3 | 1.14 | (0.35, 3.74) | 0.93 | (0.27, 3.23) | |
| P-trend | 0.002 | 0.206 | 0.381 | 0.647 | 0.963 | ||||||
| Sunburn susceptibility phenotype index | |||||||||||
| 0–1 | 35 | 1.00 | 1.00 | 30 | 1.00 | 1.00 | |||||
| 2–3 | 122 | 1.36 | (0.93, 1.97) | 1.23 | (0.85, 1.80) | 31 | 1.00 | (0.60, 1.66) | 0.98 | (0.59, 1.63) | |
| 4–5 | 119 | 1.86 | (1.27, 2.71) | 1.54 | (1.05, 2.26) | 8 | 2.13 | (0.96, 4.76) | 1.91 | (0.84, 4.38) | |
| 6–7 | 44 | 1.90 | (1.22, 2.97) | 1.44 | (0.92, 2.28) | 3 | 6.63 | (1.96, 22.5) | 5.22 | (1.47, 18.6) | |
| >7 | 17 | 2.82 | (1.58, 5.06) | 1.98 | (1.09, 3.58) | 0 | -- | ||||
| P-trend | <0.001 | 0.01 | 0.306 | 0.091 | 0.256 | ||||||
| Ever-sunburned d | |||||||||||
| No | 85 | 1.00 | 1.00 | 52 | 1.00 | 1.00 | |||||
| Yes | 252 | 1.74 | (1.36, 2.23) | 1.5 | (1.16, 1.94) | 20 | 1.24 | (0.73, 2.09) | 1.00 | (0.58, 1.74) | |
| P-value | <0.001 | 0.002 | 0.422 | 0.992 | 0.311 | ||||||
| Lifetime number of sunburns d,e | |||||||||||
| No sunburns | 85 | 1.00 | 1.00 | 52 | 1.00 | 1.00 | |||||
| ≤ 3 sunburns | 138 | 1.53 | (1.17, 2.01) | 1.38 | (1.05, 1.82) | 14 | 1.26 | (0.69, 2.28) | 1.03 | (0.56, 1.92) | |
| >3 sunburns | 114 | 2.25 | (1.70, 2.99) | 1.85 | (1.38, 2.48) | 6 | 1.29 | (0.55, 3.04) | 1.00 | (0.41, 2.41) | |
| P-trend | <0.001 | <0.001 | 0.401 | 0.962 | 0.233 | ||||||
| First age of sunburn d,e | |||||||||||
| Never sunburned | 86 | 1.00 | 1.00 | 52 | 1.00 | 1.00 | |||||
| <13 years | 73 | 2.10 | (1.53, 2.88) | 1.69 | (1.22, 2.35) | 6 | 2.79 | (1.18, 6.59) | 2.10 | (0.87, 5.11) | |
| 13 to 17 years | 82 | 2.04 | (1.50, 2.77) | 1.77 | (1.30, 2.41) | 5 | 1.37 | (0.54, 3.46) | 1.10 | (0.43, 2.82) | |
| ≥ 18 years | 96 | 1.43 | (1.07, 1.92) | 1.31 | (0.97, 1.75) | 9 | 0.91 | (0.44, 1.85) | 0.76 | (0.36, 1.57) | |
| P-trend | 0.014 | 0.082 | 0.918 | 0.55 | 0.395 | ||||||
| Family history of melanoma d | |||||||||||
| No | 330 | 1.00 | 1.00 | 71 | 1.00 | 1.00 | |||||
| Yes | 7 | 1.72 | (0.81, 3.65) | 1.48 | (0.70, 3.14) | 1 | 5.64 | (0.78, 41.0) | 5.56 | (0.76, 40.6) | |
| P-value | 0.155 | 0.304 | 0.087 | 0.091 | 0.379 | ||||||
| History of non-melanoma skin cancer d | |||||||||||
| No | 246 | 1.00 | 1.00 | 67 | 1.00 | 1.00 | |||||
| Yes | 91 | 2.31 | (1.80, 2.95) | 2.12 | (1.65, 2.72) | 5 | 6.15 | (2.44, 15.5) | 5.10 | (1.98, 13.2) | |
| P-value | <0.001 | <0.001 | <0.001 | 0.001 | 0.099 | ||||||
Abbreviations: ca, cases; RR, relative risks; CI, confidence intervals.
a
Model adjusted for age, study site, race/ethnic groups, part-white status, sex, and education.
b
Additionally adjusted for ever-sunburned status, family history of melanoma, personal history of non-melanoma skin cancer.
c
Tests heterogeneity between whites and non-whites/multiracials.
d
Also adjusted for sunburn susceptibility phenotype index.
e
One melanoma in situ case with missing information regarding lifetime number of sunburns and age of first sunburn.