With the continuous improvement of medical oncology treatment level, its indications are also being broadened. It can be broadly summarized as follows: 1. Internal medicine treatment for hematologic tumors and chemotherapy-sensitive tumors Hematologic tumors such as leukemia and multiple myeloma are systemic diseases, and chemotherapy is their main treatment modality. Testicular tumors, malignant staphyloma, choriocarcinoma, small cell lung cancer, malignant lymphoma, etc. are sensitive to chemotherapy and some patients can be cured, and their treatment is a comprehensive treatment mainly based on internal medicine. 2.Palliative treatment for advanced tumors For solid tumors that have undergone systemic dissemination and have no possibility of cure, internal medicine treatment can prolong the survival or improve the quality of life, such as advanced breast cancer, lung cancer, colorectal cancer, pancreatic cancer, kidney cancer, malignant melanoma, gastrointestinal mesenchymal tumor, etc. 3.Rescuing treatment for recurrent tumors When tumors recur after surgery or radiotherapy (also including adjuvant chemotherapy), there are often distant metastases, and chemotherapy is a common rescuing treatment for such patients. Such treatment is often palliative, such as recurrent lung cancer, breast cancer, colorectal cancer, etc. However, a few tumors may still achieve long-term survival through rescue treatment, such as testicular tumor, malignant lymphoma, etc. 4.Adjuvant therapy after surgery or radiotherapy Chemotherapy after surgery or radiotherapy for certain types of tumors can reduce recurrence and improve the cure rate. The status of adjuvant chemotherapy has been clearly defined for tumors including breast cancer, colorectal cancer, non-small cell lung cancer, ovarian cancer, osteosarcoma, etc. The status of adjuvant endocrine therapy for breast cancer and other tumors has also been established. For osteosarcoma, head and neck tumor, non-small cell lung cancer, breast cancer, gastric cancer, etc., preoperative neoadjuvant therapy can be used to remove small metastatic lesions in the body, reduce tumor load, lower preoperative staging, clarify the sensitivity of tumor to drugs, improve surgical resection rate, and preserve organs and their functions. 6.Synchronous radiotherapy and chemotherapy Chemotherapy at the same time of radiotherapy can improve the local control effect of radiotherapy on tumor through the sensitizing effect of chemotherapy drugs, and sometimes can also reduce distant metastasis to increase the cure rate and improve the quality of life, such as small cell lung cancer, head and neck tumor, etc. 7.Rescuing chemotherapy for tumor emergencies In case of emergencies caused by chemotherapy-sensitive tumors, chemotherapy can be used to relieve the symptoms and save the life of patients, so as to gain time for further treatment. For example, spinal cord compression, superior vena cava compression, intracranial hypertension caused by brain metastases, etc. 8.Special route of drug delivery In some cases, special route of drug delivery is needed to achieve therapeutic effect, such as local drug delivery to treat skin damage of certain types of malignant lymphoma, intrathecal drug delivery to treat malignant effusion, intrathecal injection to prevent or treat central nervous system invasion of leukemia or malignant lymphoma, arterial drug delivery to treat primary liver cancer, etc. 9. Adjuvant drugs for anti-tumor therapy, symptomatic treatment such as analgesia, nutritional support therapy and psychotherapy The prevention and treatment of various toxic side effects caused by chemotherapy have received more and more attention in recent years, including the prevention and treatment of malignant vomiting and diarrhea caused by chemotherapy drugs, and the application of various hematopoietic growth factors for bone marrow suppression after chemotherapy. In addition, bisphosphonates may reduce bone-related events in malignancy. From the perspective of focusing on the patient rather than only on the tumor itself, treatment of pain relief and other tumor-induced adverse syndromes (e.g., chronic fatigue, chest tightness, dizziness, depression, etc.) are also part of medical oncology treatment.