Induction treatments for acute lymphocytic leukemia
Induction treatment is also called remission induction therapy. The goal of induction treatment for acute lymphocytic leukemia (ALL) is to clear the blood and bone marrow of immature white blood cells (blast cells, blasts) and bring about a complete remission, or complete response. The induction phase of treatment usually lasts about a month.
Some people with ALL have a high number of blasts in the body (called the leukemia cell burden). People with a high leukemia cell burden have a high white blood cell count or very enlarged liver or spleen. They may be given preinduction, or prephase, therapy to lower the leukemia cell burden. This therapy usually includes a mild course of chemotherapy and may also include leukapheresisleukapheresisA procedure that uses a special machine (pheresis machine) to separate and collect specific white blood cells from withdrawn blood. The remaining blood is then returned to the body..
Chemotherapy is the primary induction treatment for ALL. The chemotherapy drugs used can vary depending on the subtype of ALL and prognostic factors. The most common induction regimen includes:
- vincristine (Oncovin)
- daunorubicin (Cerubidine, daunomycin), doxorubicin (Adriamycin) or a similar anthracycline drug
- steroids such as prednisone or dexamethasone (Decadron, Dexasone)
Based on your prognostic factors, you may be offered other drugs as part of the induction phase. These drugs include:
- cyclophosphamide (Cytoxan, Procytox)
- asparaginase (Kidrolase)
- etoposide (Vepesid, VP-16)
- high-dose methotrexate
- high-dose cytarabine (Cytosar, Ara-C)
Targeted therapy is treatment that uses drugs or other substances to target specific molecules (usually proteins) involved in cancer cell growth while limiting harm to normal cells.
A targeted therapy drug called a tyrosine kinase inhibitor may be added to the chemotherapy regimen for people with leukemia cells that have the Philadelphia chromosome (called Ph+ ALL). The most common targeted therapy used to treat Ph+ ALL is imatinib (Gleevec).
Central nervous system prophylaxis or treatment
The central nervous system (CNS) is the brain and spinal cord. Treatment given to prevent the leukemia cells from spreading to the CNS is called CNS prophylaxis. Treatments to prevent leukemia cells from spreading to the CNS or to kill leukemia cells that have spread to the CNS are often given at the same time as or after induction treatment.
CNS prophylaxis or treatment may include one or more of the following:
- chemotherapy given directly into the spinal fluid (called intrathecal chemotherapy) with methotrexate, cytarabine or a steroid such as prednisone
- high-dose methotrexate given intravenously
- radiation therapy to the brain and spinal cord
Intrathecal chemotherapy may be given during a lumbar puncturelumbar punctureA procedure in which a needle is inserted into the lower part (lumbar region) of the spinal column. or through an Ommaya reservoirOmmaya reservoirA device surgically implanted beneath the scalp that is used to deliver chemotherapy drugs directly into the cerebrospinal fluid (CSF) around the brain and spinal cord..
Radiation therapy may be given to treat ALL that has spread to the central nervous system (CNS).
Supportive therapy is important during every phase of treatment for ALL. It is used to treat the complications that usually happen with treatments for ALL and the disease itself.
Supportive therapies given during induction treatment may include:
- antibiotics, antivirals or antifungals to prevent or fight infections
- growth factors to help the bone marrow recover from chemotherapy (chemotherapy can affect the bone marrow so it doesn’t make enough healthy blood cells, which can increase the risk for infection)
- transfusions of red blood cells, platelets, fresh frozen plasma and cryoprecipitate (a product that replaces clotting factors) as needed
- drugs to bring down high levels of some chemicals in the blood that increase when many cancer cells die at the beginning of treatment (called tumour lysis syndrome)
- leukapheresis to remove large numbers of white blood cells from the blood
You may be asked if you want to join a clinical trial for ALL. Find out more about clinical trials.
I’m extremely grateful to the Canadian Cancer Society for funding my research with an Innovation Grant.
Funding lifesaving clinical trials
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