Table 1.
Selected characteristics of basal cell carcinoma (n = 880) and squamous cell carcinoma (n = 666) cases and controls (n = 780) on whom toenail arsenic and genotype data were available.
| Characteristic | Controls [n (%)] | BCC [n (%)] | SCC [n (%)] |
|---|---|---|---|
| Sex | |||
| Male | 478 (61.3) | 498 (56.6) | 423 (63.5) |
| Female | 302 (38.7) | 382 (43.4) | 243 (36.5) |
| Mean age (years ± SD) | 61.2 ± 10.5 | 58.8 ± 11.1 | 64.1 ± 8.7 |
| Severe sunburnsa | |||
| 0–2 | 471 (61.3) | 402 (46.2) | 311 (47.4) |
| ≥3 | 297 (38.7) | 469 (53.8) | 345 (52.6) |
| Pigment scoreb,c | |||
| Quartile 1 | 195 (25.0) | 83 (9.4) | 66 (9.9) |
| Quartile 2 | 197 (25.3) | 173 (19.7) | 114 (17.1) |
| Quartile 3 | 198 (25.4) | 244 (27.7) | 179 (26.9) |
| Quartile 4 | 190 (24.4) | 380 (43.2) | 307 (46.1) |
a
Missing sunburn information: 12 controls, 9 BCC, 10 SCC.
b
Pigment score was generated using a multivariate confounder score and combined data on the following pigment factors: skin reaction to first hour of intense sunshine; skin reaction to repeated sun exposure, hair color, eye color, skin color, and number of moles on back; higher pigment score represented lower pigmentation and melanin production.
c
The distribution of pigment score in controls represents the average for the pigment score in controls as generated separately for BCC and SCC.