In medicine, cancer refers to malignant tumors originating from epithelial tissues, and is the most common type of malignant tumors. Correspondingly, malignant tumors originating from mesenchymal tissues are collectively called sarcomas. There are a few malignant tumors that are not named according to the above principles, such as Wilms tumor, malignant teratoma and so on. Generally speaking, "cancer" generally refers to all malignant tumors. Cancer has biological characteristics such as abnormal cell differentiation and proliferation, loss of control of growth, invasiveness and metastasis. Its occurrence is a multi-factor and multi-step complex process, which is divided into three processes: carcinogenesis, cancer promotion, and evolution. Infection, occupational exposure, environmental pollution, unreasonable diet, and genetic factors are closely related.
This article was last edited at 2020-11-05 01:50:34