Environmental and chemical risk factors for breast cancer: A review of the current understanding of environmental toxic metal-induced breast malignancies, Nigeria perspective

Breast cancer is the most commonly diagnosed cancer in women worldwide, with an increasing number of new cases each year. The incidence of breast cancer is sadly increasing at the same time as environmental toxicants, particularly in Africa nations like Nigeria. Toxic metals are significant environmental pollutants and their toxicity results in harmful health effects. Numerous studies have described environmental exposure of humans to toxic metals in African populations, and the most commonly implicated toxic metals include arsenic, cadmium, chromium, copper, lead and nickel, all of which impact negatively on human health and the environment. Recently some of these toxic metals have been linked to the development of different types of cancers including breast cancer. Given the large burden of the morbidity and mortality associated with breast cancer, it is of the upmost importance to identify predisposing risk factors so that appropriate preventive strategies that could reduce cancer incidence can be developed and implemented. Therefore, this review aims at elucidating the role of environmental toxic metals in the development of breast cancer.