Background: The metals, including Chromium (Cr), Nickel (Ni), Cadmium (Cd), Arsenic (As), Zinc (Zn) and Selenium (Se) are considered trace elements and due to their limited quantities are essential to the human body. These elements are required as the essential components of biological enzyme systems or structural proteins. Deficiency in any of these elements leads to undesirable pathological conditions. Considering that cancer is a leading cause of mortality worldwide, our purpose of this study was to review the effect the trace elements on carcinogenicity or health maintenance.

Materials and Methods: Scopus, Pubmed, Google scholar and ScienceDirect databases were searched. Different criteria were applied to select the related articles.

Results: Results showed that the carcinogenicity of compounds of Chromium, Nickel, Cadmium and Arsenic are well-known. DNA repair systems are very sensitive targets for these elements that can cause a diminished removal of endogenous DNA lesions and increase the risk of tumor formation. Epidemiologic studies showed that Chromium and Nickel are associated with nasal and lung cancer in humans. Also, Arsenic and Cadmium exposures are associated with the increased lung cancer risk. On the other hand, many studies revealed that there was an inverse relationship between selenium exposure and risk of prostate cancer as well as between Zinc and breast cancer.

Conclusion: Although the environmental exposure is a precondition for aggregation of toxic elements, but the individual characteristics and genetic factors are also involved. The effects of trace elements are dependent to many factors.