Carcinoma in situ of the breast can correspond to the category of “breast rock (similar to breast cancer)” in TCM surgery. It can be treated with traditional Chinese medicines, such as Shenxiao Gua Puzu San combined with Kaiyu San plus and minus for liver depression and phlegm coagulation; Erxian Tang combined with Kaiyu San plus and minus for Chongren Dysregulation (which refers to the dysfunction of the Chong and Ren veins, resulting in the blockage of qi and blood). It is recommended to follow the doctor’s instructions. 1. Liver depression and phlegm coagulation: breast lumps with unchanged skin color, hardness and unclear boundary, depression, or with premenstrual breast distension, thin moss, and stringy pulse. You can take ShenXingGuaBuShan combined with KaiYuSan plus reduction. 2. Chong Ren Derangement: hard breast lumps, menstrual disorders, premenstrual breast distension and pain, or never having children after marriage, pale tongue, thin moss, thin pulse. You can take Erxian Tang with Kaiyu San plus reduction. 3. Evidence of deficiency of qi and blood: mostly found in advanced stage of cancer or surgery, patients with emaciation, yellowish or white face, dizziness, pale tongue, thin white moss and fine pulse. Ginseng Nourishing Rong Tang with added flavor can be taken. 4. Weak spleen and weak stomach: loss of appetite after surgery or radiotherapy, nausea and vomiting, swollen and tired limbs, pale tongue, thin moss, weak pulse. You can take Ginseng Ling Bai Zhu San with additional subtractions. It is difficult to achieve complete cure by pure traditional Chinese medicine treatment, but traditional Chinese medicine theories can be applied in different stages of cancer to identify and apply treatments, which can improve clinical efficacy, quality of life and prolong the survival period of patients, and the combination of Chinese and western medicines is often chosen in the treatment of cancer.