The causative factors of cancer include physical, chemical, biological and genetic factors. 1. Physical factors, physical rays such as ionizing radiation and asbestos fibers, which are common in daily life, can lead to the occurrence of cancer. 2. Chemical factors, a variety of chemical substances are also important causes of cancer, including ethylaniline, aflatoxin, nitrite, etc., which have a clear risk of causing cancer. 3. Biological factors, including bacteria and viruses, such as Hepatitis B virus and human papillomavirus, which cause infections that can lead to the development of disease, and some of them can develop into cancer. 4. Genetic factors, which are important cancer-causing factors, especially those with a family history of related tumors, have a significantly higher probability of developing cancer than normal people.