Chemotherapy is a very common form of postoperative adjuvant therapy. There are also some preoperative neoadjuvant chemotherapy or palliative chemotherapy for advanced tumors that are inoperable. The duration of chemotherapy may generally depend on the chemotherapy drug and the stage of the tumor or pre- and post-operative. For example, some chemotherapy regimens may be completed in one day, such as postoperative adjuvant chemotherapy for breast cancer, which can be completed in one day with cyclophosphamide plus adriamycin and fluorouracil. If oral capecitabine is needed, it usually takes two weeks. For other cancers like cervical cancer that require platinum-based regimens, if cisplatin is used you can choose to give a high dose in one day, which will be more responsive. It can also be given over 3-5 days. So the duration of chemotherapy is uncertain and needs to be decided according to the specific regimen.