Cancer preventive chemotherapy, chemotherapy cycle is the drug and its subsequent withdrawal each rest period until the next chemotherapy treatment when the interval began. The length of cycle of chemotherapy drugs are generally based on the pharmacokinetics of chemotherapy characteristics and tumor cell proliferation cycle to decide. Clinically, chemotherapy for solid tumors is generally 3_4 week (21:28 days) for a cycle, and the chemotherapeutic treatment is one week (7 days) as a cycle.
Cancer patients usually need to do multiple cycles of chemotherapy should be based on tumor type, stage, comprehensive treatment of the specific decision situation. For the surgical resection of primary tumor has been clinically found to have distant metastasis not to kill and in vivo surgical residual micrometastasis may exist, the general need to do 6 cycles of adjuvant chemotherapy.
Cancer preventive chemotherapy, the current view that formal, full volume is 6 cycles of chemotherapy enough to kill sensitive to chemotherapeutic drugs in vivo tumor cells, together with the remaining resistant cells with chemotherapy or even extend the number of cycles it is difficult to work. Even for those with high or highly malignant tumor recurrence, although the number of cycles can be increased, but do not advocate an unlimited extension of the time of chemotherapy.