Risk factors of cancer: a review

Abstract

Cancer has been known since BC., with rare incidence. At that time, some scientists tried to treat cancer, and some tried to find out the reason(s) behind the occurrence of cancer, and they put up many hypotheses. Nowadays, with all progression in medical technology and diagnostic methods, the causes of cancer remain unclear. But the causes of cancer can be an interaction between a person’s genetic factors and external carcinogens factors that can be divided into physical, chemical, and biological carcinogens. In this review, the risk factors of cancer were discussed.