Cancer cells do not exist in normal human body, but will appear when they are exposed to external chemical pollution, ionizing radiation, improper diet, heredity and other factors leading to gene mutation.
The formation of cancer cells requires the synergistic action of proto-oncogenes and oncogenes. When the proto-oncogenes are mutated or activated, and the oncogenes are inactivated, it will lead to the emergence of cancer cells, i.e. cancer.
The triggers are chemical infections (e.g., formaldehyde, benzopyrene, etc.), exposure to high doses of ionizing radiation, and improper diet (e.g., aflatoxin, nitrosamine, etc.).
In addition, such as retinoblastoma, breast cancer, ovarian cancer, etc. have a certain genetic predisposition.
The diagnosis of cancer requires a professional doctor to combine genetic and immunological tests with pathological results after a systematic check-up to make a clear diagnosis.