癌症是一大类疾病的总称，随着人们生活习惯的改变、生存环境的变化及人类的

Cancer is the general term for a large group of diseases. With the change of people's living habits, the change of living environment and the extension of the average life span of human beings, the prevalence of malignant tumors is getting higher and higher, and the incidence is getting younger and younger. Most cancers are the result of long-term accumulation of genetic damage and changes in human cells under the long-term action of external factors. It is a multi-factor, multi-stage, complex and gradual process. It usually takes more than ten to dozens of years to develop from normal cells to cancer cells. Time of year. Carcinogenic factors are very complex, including external factors such as chemical, physical and chronic infections, as well as self factors such as genetics, immunity, age, and lifestyle.

Cancer is the general name of a large class of diseases. With the change of people's living habits, the change of living environment and the extension of human life expectancy, the prevalence of malignant tumors is higher and higher, and the incidence is younger and younger. Most cancers are the result of long-term accumulation of gene damage and changes in human cells under the long-term action of external factors. It is a multi factor, multi-stage, complex and gradual process. It usually takes more than ten to dozens of years to develop from normal cells to cancer cells. Carcinogenic factors are very complex, including external factors such as chemical, physical and chronic infection, as well as self factors such as heredity, immunity, age and lifestyle.

Cancer is a general term for a large class of diseases. With the change of people's living habits, living environment and the extension of average life span of human beings, the prevalence of malignant tumors is getting higher and higher, and the incidence is becoming younger and younger. Most cancers are the result of long-term accumulation of gene damage and changes in human cells under the long-term influence of external factors. It is a multi-factor, multi-stage and complex gradual process. It usually takes more than ten years to several decades for normal cells to develop into cancer cells. Carcinogenic factors are very complicated, including external factors such as chemical, physical and chronic infection, and self factors such as heredity, immunity, age and lifestyle.