Pleomorphic adenoma of the lacrimal gland.

Abstract

<h3>Background:</h3> This study examines whether insufficient ultraviolet B (UVB) irradiance, a marker of vitamin D inadequacy, might contribute to lung cancer incidence. <h3>Methods:</h3> The association of latitude and UVB irradiance with age-adjusted incidence rates of lung cancer in 111 countries was investigated. Independent associations with UVB irradiance, cloud cover, anthropogenic aerosols, and cigarette smoking, were assessed using multiple regression. <h3>Results:</h3> Latitude was positively related to incidence rates in men (<i>R</i>² = 0.55, p&lt;0.01) and women (<i>R</i>² = 0.36, p&lt;0.01). In men, cigarette consumption (p&lt;0.001) was positively related to risk, whereas UVB irradiance was inversely associated (p = 0.003). There were positive associations with UVB absorbers, in particular cloud cover (p = 0.05) and aerosol optical depth (p = 0.005). The <i>R</i>² for the model was 0.78 (p&lt;0.001). UVB irradiance was also inversely associated with incidence rates in women (p = 0.0002), whereas cigarette consumption (p&lt;0.001), total cloud cover (p = 0.02) and aerosol optical depth (p = 0.005) were positively associated. The <i>R</i>² for the model was 0.77 (p&lt;0.001). <h3>Conclusions:</h3> Lower levels of UVB irradiance were independently associated with higher incidence rates of lung cancer in 111 countries.