1. Herceptin: A recombinant DNA-derived humanized monoclonal antibody that acts selectively on the extracellular site of human epidermal growth factor receptor-2 (HER2). Herceptin alone has similar efficacy to chemotherapeutic drugs, but without the common adverse effects of chemotherapeutic drugs such as alopecia, mucositis, and hematological toxicity, and is well tolerated. It is rapidly absorbed in the gastrointestinal tract in the form of prodrug and metabolized to 5-Fu with antitumor activity in the liver and tumor tissues. thymidine phosphorylase (TP) is the last enzyme in the activation process of Xiloda, and the concentration of TP is high in tumor tissues, especially in breast cancer, gastric cancer and colorectal cancer. The concentration of TP is significantly higher in tumor tissues, especially in breast cancer, gastric cancer, and colorectal cancer than in normal tissues. Therefore, the cancer tissues can make more Hironda to transform 5-Fu, while the chance in normal tissues is small, thus avoiding the damage of 5-Fu to normal tissues, so the anti-tumor activity of Hironda is high, but the systemic toxicity is light, at present, it has been approved in many countries for advanced breast cancer patients who failed paclitaxel and anthracycline treatment. 3.Fury: Letrozole is a new generation of aromatase inhibitor, and aromatase inhibitors are generally well tolerated. Common adverse effects are gastrointestinal disturbances, weakness, headache, hot flashes, and musculoskeletal pain. It is a synthetic benzotriazole derivative. Letrozole eliminates the stimulating effect of estrogen on tumor growth by inhibiting aromatase and causing estrogen levels to decrease. 4.Speedle: The growth of breast cancer cells depends on the presence of estrogen. The estrogens (estrone and estradiol) in women’s postmenopausal circulation are converted from androgens (androstenedione and testosterone) in the adrenal glands, liver, muscle and fat mainly through aromatase in peripheral tissues. Blocking estrogen production by inhibiting aromatase is therefore an effective and selective treatment for postmenopausal hormone-dependent breast cancer. Exemestane is an irreversible steroidal aromatase inactivator, structurally similar to the natural substrate of the enzyme androstenedione, a pseudo-substrate of the aromatase, which can inactivate the enzyme by irreversibly binding to its active site, thus significantly reducing the level of estrogen in the blood circulation of menopausal women, but has no significant effect on the biosynthesis of corticosteroids in the adrenal glands. 5.Paclitaxel injection: Paclitaxel has been approved by FDA for the adjuvant treatment of progressive breast cancer, and can also be used for the treatment of patients who have failed combination chemotherapy or relapsed within 6 months of adjuvant treatment. Common adverse effects of paclitaxel are myelosuppression, myalgia, arthralgia, mucositis, nausea and vomiting, as well as hair loss and peripheral nerve damage. Fever and neutropenia are also common. The incidence of severe allergic reactions such as allergy and respiratory distress, hypotension, angioneurotic edema, and common urticaria is 30%. Exposure to paclitaxel accumulates a large number of microtubules in the cells, and the accumulation of these microtubules interferes with various cell functions, especially stopping cell division at mitotic phase and blocking normal cell division. Doxorubicin is a semi-synthetic paclitaxel antitumor drug that inhibits the number of free tubules by binding to microtubule proteins to synthesize stable microtubules and inhibit their depolymerization, thus inhibiting cell mitosis and leading to cell necrosis and apoptosis. Doxorubicin is effective against colon cancer, breast cancer and lung cancer in mice. Cross-resistance does not occur in cell lines resistant to fluorouracil or paclitaxel. The efficiency of doxorubicin monotherapy for metastatic breast cancer treated for the first time with chemotherapy is 68%, for previously treated metastatic breast cancer the efficiency is 32%-58%, and for anthracycline-resistant metastatic breast cancer the efficiency is 32%-57%.