Depends on type.... There are many types of leukemia (all, aml, cml, cll) and each have different treatment regimens. Age also plays a factor (adult vs. Pediatric treatment protocols). For example, AML is intensive, but relatively short (~9 months). All can be 3-4 years. CML treatment can be lifelong, though is can be treated with oral pills taken daily.
Cvariable. Depends on thetype.
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.
It depends. There are many different types of leukemia and the treatment varies by type of leukemia. Some involve a few months of chemotherapy which may be followed by a bone marrow transplant. Others may involve chemo for a year or more. Some types are treated by oral medications that have to be taken for a lifetime.