Treatment of ALL
In most patients, intense chemotherapy is needed to achieve a remission in ALL. Unlike treatment for other types of acute leukemia, the regimens used to treat ALL are specifically toxic to lymphoblasts, while being relatively sparing of other types of blood producing stem cells.
As a result, ALL patients experience a greater cancer cell kill with a less severe drop in cell counts over a shorter duration of time. This means that the marrow can recover more quickly, and complications of low blood counts are less likely. Initial treatment of ALL is usually provided on a hospital inpatient basis, but once a remission is achieved, the remaining therapy is often given on an outpatient basis.
Also unlike other forms of leukemia, it is common for ALL cells to infiltrate other organs and remain hidden there, even after remission is achieved. Early in the disease process, ALL cells can travel to the CSF and central nervous system (CNS). Because chemotherapy drugs are usually not capable of passing from the bloodstream into the CSF, the cancer cells are sheltered there and will eventually multiply and lead to relapse unless treated properly.
The goal of treatment for ALL is to eliminate the leukemia cells from the bone marrow and lymph tissue, as well as from the sanctuary organs and CNS.
Chemotherapy for ALL is given intravenously. Since you might require treatment over many months or even years, your doctor may choose to insert a catheter called a central venous catheter, which provides longterm access to your veins without having to be poked repeatedly. Otherwise, you will receive your chemotherapy through a vein, usually in your arm.
While the initiation of the intravenous site (IV) can feel like a pinch, the infusion of your chemotherapy should not cause you any discomfort. If it does, you need to let your nurse or healthcare provider know immediately.
You will also need CNS prophylaxis to eliminate any cancer cells that have entered your CSF. CNS prophylaxis chemotherapy is called intrathecal chemotherapy. Your doctor will inject chemotherapy directly into the fluid surrounding your spine. If you had a lumbar puncture, or spinal tap as part of the diagnosis of your leukemia, this process is very similar.
You may also receive radiation treatments to kill leukemia cells in your CNS. Radiation treatments of this type are painless, and may remind you of an X-ray.
About a quarter of ALL cases are a subtype called “Philadelphia-positive ALL,” in which the cancer cells show a genetic abnormality referred to as the Philadelphia chromosome. This type of ALL is treated with a group of drugs called tyrosine kinase inhibitors (TKIs) in addition to regular chemotherapy. Examples of TKIs are imatinib mesylate (Gleevec), dasatinib (Sprycel) or nilotinib (Tasigna).
Some patients with high risk ALL may be candidates for stem cell transplantation. Your doctor will evaluate the characteristics of your leukemia cells, how they respond to therapy, and donor availability to help determine if stem cell transplant is right for you.
Even after a remission is achieved, treatment to maintain the remission may continue for many months. This “maintenance therapy” uses different combinations of chemotherapy drugs to eliminate any remaining cancer cells in your body. This ongoing therapy often continues for two to three years.