The causes of breast cancer are not yet fully understood, but they are related to genetic factors, radiation, endocrine factors, diet, and other factors. 1. Genetic factors: Daughters or sisters of breast cancer patients have a higher risk of developing breast cancer than normal people. 2. Radiation: radioactive exposure can also increase the incidence of breast cancer. 3. Endocrine factors: estrogen is obviously related to the occurrence of breast cancer, and prolactin can promote the occurrence of breast cancer. 4. Diet: diet and obesity can affect the concentration of estrogen, and fat intake is related to the incidence of breast cancer. 5. Other factors: the incidence rate of breast cancer in married and childbearing people is lower than that in unmarried and childless people. Breast cancer patients should go to the hospital in time and receive standardized treatment under the guidance of doctors.