ABSTRACT
We critically evaluated the etiologic role of inorganic arsenic in human prostate cancer. We assessed data from relevant epidemiologic studies concerning environmental inorganic arsenic exposure. Whole animal studies were evaluated as were in vitro model systems of inorganic arsenic carcinogenesis in the prostate. Multiple studies in humans reveal an association between environmental inorganic arsenic exposure and prostate cancer mortality or incidence. Many of these human studies provide clear evidence of a dose-response relationship. Relevant whole animal models showing a relationship between inorganic arsenic and prostate cancer are not available. However, cellular model systems indicate arsenic can induce malignant transformation of human prostate epithelial cells in vitro. Arsenic also appears to impact prostate cancer cell progression by precipitating events leading to androgen independence in vitro. Available evidence in human populations and human cells in vitro indicates that the prostate is a target for inorganic arsenic carcinogenesis. A role for this common environmental contaminant in human prostate cancer initiation and/or progression would be very important.
Realizamos uma avaliação crítica do papel etiológico do arsênico inorgânico no câncer de próstata humano. Avaliamos dados de estudos epidemiológicos relevantes referentes à exposição ao arsênico inorgânico ambiental. Foram avaliados estudos com animais completos, bem como sistemas de modelo in vitro de carcinogênese decorrente de arsênico inorgânico na próstata. Estudos múltiplos em seres humanos revelaram uma associação entre exposição ao arsênico inorgânico ambiental e mortalidade por ou incidência de câncer de próstata. Muitos desses estudos em seres humanos oferecem indícios claros de uma relação dose-resposta. Não se encontram disponíveis modelos animais completos relevantes que mostrem uma relação entre arsênico inorgânico e câncer de próstata. Contudo, os sistemas de modelos celulares indicam que o arsênico é capaz de levar a transformações malignas de células epiteliais da próstata humana in vitro. Aparentemente, o arsênico também tem um impacto na progressão do câncer de próstata ao precipitar eventos que levam à independência de andrógeno in vitro. Os indícios disponíveis em populações humanas e células humanas in vitro indicam que a próstata é alvo da carcinogênese de arsênico inorgânico. Um papel para esse contaminante ambiental comum na iniciação e/ou progressão do câncer de próstata humano seria de suma importância.
ABSTRACT
Arsenic exposure from burning coal with high arsenic contents occurs in southwest Guizhou, China. Coal in this region contains extremely high concentrations of inorganic arsenic. Arsenic exposure from coal-burning is much higher than exposure from arsenic-contaminated water in other areas of China. The current status and prevention strategies for arsenic poisoning from burning high-arsenic coal in southwest Guizhou, China, is reported here. Over 3,000 arsenic-intoxicated patients were diagnosed based on skin lesions and urinary arsenic excretion. Non-cancerous toxicities and malignancies were much more common and severe in these patients than in other arsenic-affected populations around the world. The high incidence of cancer and arsenic-related mortality in this cohort is alarming. Chelation therapy was performed but the long-term therapeutic effects are not satisfactory. The best prevention strategy is to eliminate arsenic exposure. Funds from the Chinese Government are currently available to solve this arsenic exposure problem. Strategies include the installation of vented stoves, the use of marsh gas to replace coal, health education, the improvement of nutritional status, and the use of various therapies to treat arsenic-induced skin and liver diseases.