Occupation and skin cancer: the results of the HELIOS-I multicenter case-control study

BACKGROUND Non-melanoma skin cancer (NMSC) is the most frequent tumour among Caucasian populations worldwide. Among the risk factors associated with this tumour, there are host-related factors and several environmental agents. A greater likelihood of high exposure to physical agents (with the exception of solar radiation) and chemical agents depends on the work setting. Our objective is to evaluate the role of occupational exposures in NMSC, with special emphasis on risk factors other than solar radiation and skin type. METHODS We analysed 1585 cases (1333 basal cell carcinoma (BCC) and 183 squamous cell carcinoma (SCC)) and 1507 controls drawn from the Helios-I multicenter study. Odds ratios (OR) and 95% confidence intervals (CI) were estimated using logistic regression mixed models. RESULTS For NMSC as a whole (both histological types), miners and quarrymen, secondary education teachers, and masons registered excess risk, regardless of exposure to solar radiation and skin type (OR 7.04, 95% CI 2.44-20.31; OR 1.75, 95% CI 1.05-2.89 and OR 1.54, 95% CI 1.04-2.27, respectively). Frequency of BCC proved higher among railway engine drivers and firemen (OR 4.55; 95% CI 0.96-21.57), specialised farmers (OR 1.65; 95% CI 1.05-2.59) and salesmen (OR 3.02; 95% CI 1.05-2.86), in addition to miners and quarrymen and secondary education teachers (OR 7.96; 95% CI 2.72-23.23 and OR 1.76; 95% CI 1.05-2.94 respectively). The occupations that registered a higher risk of SCC (though not of BCC) were those involving direct contact with livestock, construction workers not elsewhere classified (OR 2.95, 95% CI 1.12-7.74), stationary engine and related equipment operators not elsewhere classified (OR 5.31, 95% CI 1.13-21.04) and masons (OR 2.55, 95% CI 1.36-4.78). CONCLUSION Exposure to hazardous air pollutants, arsenic, ionizing radiations and burns may explain a good part of the associations observed in this study. The Helios study affords an excellent opportunity for further in-depth study of physical and chemical agents and NMSC based on matrices of occupational exposure.