Skin cancer risk in outdoor workers: A European multicenter case-control study

Background Exposure to ultraviolet radiation (UVR) is the most important external risk factor for skin cancer. Outdoor workers, who are exposed to high ambient UVR levels are at increased risk. Objective To compare outdoor with indoor workers in terms of: (i) skin cancer risk factors, and (ii) risk of developing skin cancer. Methods Using descriptive methods and a large multicenter European case-control study, we compared risk factor patterns between outdoor (N = 1416) and indoor workers (N = 1863). Risk of developing basal cell carcinoma (BCC), squamous cell carcinoma (SCC), melanoma and actinic keratosis (AK) were analysed by type of work using multivariate logistic regression models, for three categories of work: indoor; farming/construction; other outdoor work. Results Although skin phototype was equally distributed by type of work, significantly less outdoor than indoor workers used sunscreen in their own country (44.3% vs. 60.2%), but had more outdoor hobbies (66.2% vs. 58.2%). Outdoor workers had lower educational levels, and felt less confident in understanding medical information and filling medical forms (all P < 0.001). Outdoor workers had more signs of photodamage (78.1% vs. 65.5%) and among the skin cancer patients, 37.7% of outdoor workers vs. 28.6% of indoor workers had ≥2 skin cancers diagnosed during their lifetime. Multivariate logistic regression models showed significantly increased risk of outdoor vs. indoor work for AK (ORother outdoor= 1.55, ORfarming/construction= 2.58), SCC (ORother outdoor= 1.32, ORfarming/construction= 2.77) and BCC (ORother outdoor= 1.53, ORfarming/construction= 1.83). No significant associations were found for melanoma. The risk of all types of skin cancer and AK was significantly increased for workers with ≥5 years of outdoor work. Conclusions Outdoor workers had more risk behaviour with similar constitutional skin cancer risk factors: more UV exposure (both occupational and leisure) and less sunscreen use and lower health literacy. This results in higher exposure, more photodamage and an increased risk of developing AK, BCC and SCC.