Mammary gland hyperplasia may become cancerous, but the chances of cancer are small. There is no clear clinical evidence that mammary hyperplasia is necessarily cancerous, but there is a link between hyperplasia and cancer. Some patients with mammary hyperplasia may indeed become cancerous and develop malignant tumors, but it is not certain that mammary hyperplasia will transform into breast cancer. Mammary hyperplasia is mainly due to the imbalance of estrogen and progesterone in the body, which leads to the formation of mammary gland rejuvenation, which is related to female endocrine disorders in the body, while the occurrence of breast cancer is mostly related to genetic factors, acquired dietary habits, and special manifestations of patients. It has been found that some special breast enlargement can develop into cancer, especially those with adenoma-like changes and nodules, and the effect of medication is relatively poor. However, there is no definite time for cancer to develop, so regular auxiliary examinations such as ultrasound, mammogram and cytology aspiration can be performed to confirm the diagnosis if necessary, so as to prevent the transformation of mammary hyperplasia into cancerous nodules as early as possible.