Breast cancer

Abstract

Breast cancer is the most common neoplasm in women, and it is a rare cancer in men. A handful of occupational exposures, including ethylene oxide and shift work that involve circadian disruption, have been linked, with limited human evidence, to an increased risk of breast cancer in women. Evidence is still being gathered regarding other occupational and environmental exposures, such as several hydrocarbons and certain components of air pollution, that are suspected to play an etiologic role. Therapeutic exposure to several medications and to X-radiation and γ-radiation has been linked with sufficient evidence to female breast cancer; however, the weight of occupational evidence for these same carcinogens is still deemed limited or insufficient. Between 2 and 5% of the breast cancers diagnosed now are estimated to be attributable to occupational exposures; as the most common cancer among women, breast cancer thus represents an important burden on our societies. Although no occupational exposures have yet been linked specifically to male breast cancer, similarities between male and female breast cancers suggest potential common causal factors. As only about 30% of new cases of breast cancer can be explained by known risk factors, continued research on the relationship between environmental and occupational exposures and breast cancer is warranted.