The duration of chemotherapy for lung cancer varies depending on the drug used and the patient’s hospital stay. Because different chemotherapy drugs are given in different ways, some of them may take 1 day while others may take about 2 weeks, so the time varies according to the drugs and the way they are administered. The chemotherapy cycle is the time from the first dose to the next dose, which is usually about 3-4 weeks, but the actual duration of dosing needs to depend on the method of dosing, which may be 1-3 days or about 7-8 days.