Tumor treatment has now entered the era of comprehensive treatment. The task of doctors is how to master and arrange various effective treatments to improve the efficacy and cure more patients. Internal medicine treatment focuses on the whole body, through drug therapy – mainly chemotherapy, to kill tumor cells and enhance the immune function of the body to the maximum extent, and the time when it can play a role in comprehensive tumor treatment is as follows: (a) Adjuvant chemotherapy Adjuvant chemotherapy refers to the chemotherapy after surgical resection or radiotherapy for the primary tumor, also called (1) Adjuvant chemotherapy refers to chemotherapy after surgical resection or radiotherapy for the primary tumor, also called postoperative or post-radiation chemotherapy. Many tumor patients may mistakenly believe that they have been “cured” by surgery or radiotherapy and do not need to do chemotherapy again. Most of them have already developed micro-metastases, which are the root cause of future recurrence or metastasis. The proliferation of micro metastases can become active after resection of the primary site or radiotherapy, plus the systemic tumor load is at a very low level at this time, which will all facilitate chemotherapy to play a killing role. The elimination of subclinical micro-metastases helps to improve the cure rate of patients after surgery or radiotherapy. Therefore, post-surgery or post-radiotherapy patients should not rest on their laurels, but should continue chemotherapy with a bang, until every cancer cell is completely destroyed. Tumors for which adjuvant chemotherapy can improve the cure rate include breast cancer, colorectal cancer, osteosarcoma, small cell lung cancer as well as Ewing tumor, pediatric rhabdomyosarcoma and testicular tumor. The need to continue chemotherapy after breast cancer surgery is well recognized in clinical practice and is a prime example of the success of adjuvant chemotherapy. Many breast cancer patients have deeply benefited from adjuvant chemotherapy. (ii) Neoadjuvant chemotherapy This modality of chemotherapy is the opposite of adjuvant chemotherapy, which is administered before the patient’s surgery or radiotherapy. This is because there are tumors that are limited but have large masses or significant local infiltration, and there are difficulties in immediate surgical treatment, or it is thought that surgery first will cause greater trauma to the patient. The purpose of applying chemotherapy at this time is twofold: firstly, it is hoped that the local tumor will shrink after chemotherapy to create conditions for surgical removal of tumor or radiotherapy and reduce the damage of local treatment; secondly, it is to remove the micro metastases that may exist so as to improve the prognosis. In addition, the results of pathological examination of surgical specimens can also provide an understanding of the effects of chemotherapy on cancerous tissues, which provides a basis for the selection of chemotherapy drugs after surgery. The tumors for which neoadjuvant chemotherapy is applicable include: anal canal cancer, bladder cancer, breast cancer, laryngeal cancer, osteosarcoma and soft tissue sarcoma, non-small cell lung cancer, esophageal cancer, nasopharyngeal cancer and other head and neck tumors. (3) Treatment of advanced patients Most of the advanced patients’ tumors have spread throughout the body and are no longer suitable for local treatment such as surgery or radiotherapy, so chemotherapy has become the main treatment method. Among the advanced patients, some of them have already reached the advanced stage when cancer is diagnosed, while some others have entered the advanced stage due to recurrence or metastasis even after inadequate or sufficient treatment. Recurrence or metastasis is certainly difficult to be treated, but patients should have firm confidence and not give up the chance of treatment. The purpose of chemotherapy is to treat patients with advanced tumors. For advanced tumors, chemotherapy is an effective treatment to achieve cure, improvement, improve the quality of survival and prolong the survival period.