It is unscientific and wrong to say that the bigger the breasts are, the easier it is to get breast cancer. The pathogenesis of breast cancer has nothing to do with the size of breasts, it is caused by the long-term joint action of many factors, mainly related to hormones, heredity, mental and other factors. The causes of breast cancer are not yet fully understood, but it is not true that the larger the breasts are, the more likely they are to get breast cancer. Breast cancer is caused by the long-term joint action of many factors, such as: 1. Hormones: the mammary gland is the target organ of many kinds of endocrine hormones, such as estrogen, progesterone and prolactin, etc., and estrone and estradiol among them are directly related to the development of breast cancer. 2. Heredity: patients whose parents, siblings and children have a history of breast cancer have a risk of developing the disease two to three times higher than that of the general population. 3. Mental: Being in unstable mood for a long time, such as mental depression and excessive tension, is one of the main factors leading to various diseases. Combined with other factors can jointly cause breast cancer. In addition to the above factors, breast hyperplasia, over-nutrition, obesity and other factors may cause breast cancer. Once diagnosed with breast cancer, patients are advised to undergo treatment as early as possible.