In my clinic, I often get questions from patients about whether breast enlargement will definitely turn into breast cancer. The following is the result of an authoritative foreign study, which I hope will clear up the confusion for our patients. The rate of developing invasive breast cancer at 10-20 years of follow-up was used as the risk level when comparing women with different pathomorphological lesions defined by biopsy with women of the same age who did not have breast biopsy. Cystic hyperplasia of the breast was classified by histologic type as cyst, sweat gland hyperplasia, adenopathy, sclerosing adenopathy, inflammation, calcification, intraductal papilloma, and/or epithelial hyperplasia. The risk of breast cancer was not increased for nonproliferative lesions such as cysts, sweat gland hyperplasia, adenopathy, sclerosing adenopathy or inflammation; those with ductal epithelial hyperplasia without atypical hyperplasia, including general, moderate or exuberant hyperplasia, had a mildly increased risk compared to the general population (1.5 to 2 times the risk of breast cancer in the control group); those with epithelial atypical hyperplasia, including ductal atypia and lobular atypia The risk was moderately increased (4-5 times) in those with epithelial atypical hyperplasia, including lobular atypical hyperplasia and lobular atypical hyperplasia; and the risk of invasive carcinoma was highly increased (8-10 times) in those with carcinoma in situ, including lobular carcinoma in situ and ductal carcinoma in situ. The results further clarify the significance of atypical hyperplasia in the carcinogenesis of benign breast diseases: the development process is normal breast epithelial cells → general proliferating epithelial cells → atypical proliferating epithelial cells → carcinoma in situ → invasive carcinoma.