How long could chemo last for someone with leukemia?

Need some detail: Here. Chronic leukemias may be on continuous, or interrupted, therapy for years. Acute leukemias are on intensive therapies for 6-8 months, and sometimes maintenance for 2 years.

Hard to say...: It depends a lot on multiple factors including type of leukemia, age of patient, stage of disease, coexisting illnesses, etc. Initially, it is usually at least several weeks but it may last for months function of how fast or how slow the patient responds to therapy.