Early symptoms of non-invasive breast cancer, also known as carcinoma in situ, may be the discovery of a breast lump. Also some patients may have nipple overflow or nipple invagination, which are the main symptoms. Because breast tissue is superficial and can be felt in person, it is recommended that people with a high risk family history or a history of other benign breast diseases should detect it early by touching the breast every month after 3-7 days of menstrual cleansing. Breast self-examination or touching the breast by another person is recommended for early detection if a breast lump appears. After consultation, the doctor will usually give the appropriate examination, for example, for young women, the doctor may ask to go for breast ultrasound examination. If the ultrasound finds that there is a problem that requires puncture, a coarse or fine needle biopsy can be done and sent to the pathology for cytological examination to see if there are cancer cells. If there are cancer cells, it can be diagnosed as cancer. For whether it is in situ cancer or whether it is non-invasive breast cancer, you may need to do major pathology after surgery to confirm the diagnosis.