Chemotherapy generally has a cycle, the need for individualized medication, according to the patient’s different tolerance, the use of different programs, the interval may also make a difference, as follows: 1, commonly used intravenous chemotherapy, the use of 21-day program, that is, the interval between the second chemotherapy for three weeks, through the interval of the time can be used to strengthen the nutrition, improve the body’s resistance, to help reduce the side-effects of chemotherapy, as well as the four-week There is also a four-week program, that is, an interval of 28 days, for elderly patients with poorer resistance and poorer nutritional status, there may be a longer interval; 2, there are some oral drugs may be a short interval, such as the commonly used oral Tegretol or capecitabine, usually two weeks of medication and one week’s rest, that is, one week’s interval.