Is ultraviolet exposure acquired at work the most important risk factor for cutaneous squamous cell carcinoma? Results of the population-based case-control study FB-181.

BACKGROUND: Squamous cell carcinoma (SCC) is one of the most frequent types of cancer constituting a significant public health burden. Prevention strategies focus on limiting ultraviolet (UV) exposure during leisure time. However, the relative impact of occupational and nonoccupational UV exposure for SCC occurrence is unclear. OBJECTIVES: To investigate the association between occupational and nonoccupational UV exposure for SCC in a multicentre population-based case-control study hypothesizing that high occupational UV exposure increases the risk of SCC. METHODS: Consecutive patients with incident SCC (n = 632) were recruited from a German national dermatology network. Population-based controls (n = 996) without history of skin cancer were recruited from corresponding residents' registration offices and propensity score matched to cases. Lifetime UV exposure, sociodemographic and clinical characteristics were assessed by trained physicians. Occupational and nonoccupational UV exposure doses were estimated by masked investigators using established reference values. Odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were assessed using conditional logistic regression adjusting for relevant confounders. RESULTS: Total solar UV exposure was significantly associated with increased SCC. The OR for high (> 90th percentile) vs. low (< 40th percentile) and high vs, moderate (40-59th percentile) occupational UV exposure was 1·95 (95% CI 1·19-3·18) and 2·44 (95% CI 1·47-4·06) for SCC. Adjusting for occupational UV exposure, nonoccupational UV exposure was not significantly related to SCC incidence. Dose-response relationships were observed for occupational but not for nonoccupational solar UV exposure. CONCLUSIONS: Solar occupational UV exposure is a major determinant of incident SCC. Our findings indicate that prevention strategies should be further expanded to the occupational setting.

An approximation of occupational lifetime UVR exposure: algorithm for retrospective assessment and current measurements.

BACKGROUND: Since non-melanoma skin cancer (NMSC) has been adopted as an occupational disease in Germany, in any single suspected case a retrospective estimation of the outdoor workers' occupational UVR exposure is mandatory. OBJECTIVE: The aim of this study was to introduce the recent German standard procedure as a mathematical algorithm for retrospectively estimating individual occupational UVR lifetime exposure. In addition, to present results of exemplary on-the-job UVR dosimetry measurements on outdoor workers during their various occupational activities. These dosimetry data form the basis of the mathematical model for UVR exposure estimation. METHODS: On-the-job personal dosimetry in various outdoor professions was conducted using the GENESIS-UV measurement system for individual UVA/UVB exposure assessment. The algorithm is derived from the results of these pars pro toto exemplary dosimetric measurements. For retrospective UVR lifetime estimation in suspected cases, a standardized patient interview serves as input and delivers all necessary information for using the algorithm. With defined factors, an individual adjustment is achieved. RESULTS: Inserting the data derived from the patient interview, the algorithm shows to be feasible to calculate the lifetime UVR exposure retrospectively. As an example, an assessment for a 67-year-old agricultural teacher with three distinct occupational UVR exposure episodes is calculated. CONCLUSION: The presented algorithm has proven to facilitate the anamnestic procedure to estimate the lifetime UVR dose of exposed outdoor workers. With a recently developed computer-based tool, standardized interviews of suspected workers with NMSC become simple. UVR dose as well as matching of requirements for recognition as an occupational disease in an individual worker are calculated automatically. Furthermore, with ongoing on-the-job measurements, a database is created to continuously adjust the algorithm's reference values for the various UVR-exposed occupations. In addition, a job exposure matrix UVA/UVB is created as a pivotal tool for improved health and safety of outdoor workplaces and prevention of occupational actinic damage to the skin.

Basal cell carcinoma risk and solar UV exposure in occupationally relevant anatomic sites: do histological subtype, tumor localization and Fitzpatrick phototype play a role? A population-based case-control study.

BACKGROUND: A two-fold risk increase to develop basal cell carcinoma was seen in outdoor workers exposed to high solar UV radiation compared to controls. However, there is an ongoing discussion whether histopathological subtype, tumor localization and Fitzpatrick phototype may influence the risk estimates. OBJECTIVES: To evaluate the influence of histological subtype, tumor localization and Fitzpatrick phototype on the risk to develop basal cell carcinoma in highly UV-exposed cases and controls compared to those with moderate or low solar UV exposure. METHODS: Six hundred forty-three participants suffering from incident basal cell carcinoma in commonly sun-exposed anatomic sites (capillitium, face, lip, neck, dorsum of the hands, forearms outside, décolleté) of a population-based, case-control, multicenter study performed from 2013 to 2015 in Germany were matched to controls without skin cancer. Multivariate logistic regression analysis was conducted stratified for histological subtype, phototype 1/2 and 3/4. Dose-response curves adjusted for age, age2, sex, phototype and non-occupational UV exposure were calculated. RESULTS: Participants with high versus no (OR 2.08; 95% CI 1.24-3.50; p = 0.006) or versus moderate (OR 2.05; 95% CI 1.15-3.65; p = 0.015) occupational UV exposure showed a more than two-fold significantly increased risk to develop BCC in commonly UV-exposed body sites. Multivariate regression analysis did not show an influence of phototype or histological subtype on risk estimates. The restriction of the analysis to BCC cases in commonly sun-exposed body sites did not influence the risk estimates. The occupational UV dosage leading to a 2-fold increased basal cell carcinoma risk was 6126 standard erythema doses. CONCLUSION: The risk to develop basal cell carcinoma in highly occupationally UV-exposed skin was doubled consistently, independent of histological subtype, tumor localization and Fitzpatrick phototype.