Treating Acute Lymphoblastic Leukemia

Once a diagnosis of leukemia is confirmed, a treatment plan is outlined. The treatment used is based upon certain factors related to the patient and leukemia type. These factors include:
  • Age of the patient at diagnosis. Children less than one year of age or 10 years of age and older at diagnosis require more aggressive treatment for cure.
  • White blood count at diagnosis. Children with a white blood count greater than 50,000 require more aggressive treatment.
  • Subtype of leukemia. There are several different types of ALL. “B cell precursor” is the most common; “T cell” is less common.
  • Central nervous system leukemia. Children withleukemia cells (blasts)in the spinal fluid at diagnosis require more aggressive treatment.
  • Testicular leukemia. One to two percent of boys have leukemia cells in the testicles at the time of diagnosis. This is determined by examining the testicles; in some cases a biopsy could be required. Stronger treatment is usually given to boys that have leukemia in the testicles, and some will need to get radiation therapy.
  • Chromosomal alterations in the leukemia cell: Cancer cells often display genetic mistakes that have been acquired, meaning that they were not passed down from the parents to the child. At least 90% of ALL cases include such abnormalities and can affect the type of treatment.
  • Response to therapy: Children whose leukemia responds more slowly to initial treatment require more aggressive treatment. Response to treatment used to be measured mainly by counting the percentage of leukemia cells present in the bone marrow at various times in the first month of therapy. Currently, minimal residual disease (MRD) tests are done on bone marrow (and sometimes blood) specimens from most patients during the first month of treatment. These MRD tests can detect as few as 1 leukemia cell among 10,000-100,000 normal cells. The results of MRD tests may change the type of treatment.

Types of Treatment

ALL is a cancer of the blood, so treatment is systemic, meaning it affects the entire body. At the time of diagnosis, the healthcare team will insert a central line to provide treatment.

Chemotherapy is the mainstay of treatment.
  • Induction: The first phase of treatment usually lasts four weeks. Children receive three or four drugs by mouth, intravenously (into a vein), or into the spinal fluid (intrathecal delivery). The combination of drugs depends upon the leukemia factors as above. The goal of this phase is to kill the leukemia cells and allow normal blood cells to return.
A bone marrow aspirate is performed at the end of this phase. The bone marrow is examined under a microscope, andis expected to show only normal cells. This is called remission. This does not mean that the child is cured, because without further treatment the disease will return. However, it is a very important first step on the road towards being cured. Nearly 98 of every 100 children with ALL enter remission at the end of the first month of treatment. Other tests (such as minimal residual disease) may be performed on the bone marrow and may be more sensitive at finding leukemia cells than looking under a microscope.
  • Consolidation: The second phase of treatment lasts from 12-16 weeks. Different drugs from those used during Induction are given by mouth and intravenously.
The purpose of the consolidation phase is to kill leukemia cells that may remain after the drugs used in induction. Another main focus is on treating and preventing the growth of leukemia cells within the central nervous system (CNS prophylaxis). To accomplish this, spinal taps with intrathecal chemotherapy (directly into the spinal fluid) are performed weekly. For certain types of leukemia, or if leukemia cells were present in the spinal fluid at the time of diagnosis, radiation therapy may be given to the brain and the spinal column during this phase. In most cases, part of the Consolidation phase will include treatment with the chemotherapy drug methotrexate. Methotrexate is given intravenously, either at lower doses in the clinic or at higher doses that require a 2-3 day stay in the hospital.
  • Delayed intensification: This 8-week phase of treatment includes medicines similar to those given in Induction and Consolidation. This has been shown to be helpful in preventing leukemia from returning. The exact timing of the doses and the specific drugs used depend upon the individual characteristics of a particular child’s disease.
  • Maintenance: The final phase of treatment lasts two or three years. Maintenance is much less intensive than the previous treatment and consists mostly of oral medications given at home. There are also intermittent intravenous and intrathecal medications given throughout this phase.

Radiation to the brain: Most of the chemotherapy drugs used to treat ALL don’t get into the brain and spinal fluid very well. Because of this, special approaches have to be used to kill ALL cells in these areas. All children with ALL receive intrathecal chemotherapy given into the spinal fluid during a lumbar puncture. In some cases, radiation therapy is also delivered to the brain. Radiation treatments are usually given 5 days a week for about 2 weeks.

Radiation to the testicles: In most cases, ALL that is present in the testicles at diagnosis goes away quickly during the first month of treatment. If this does not happen and leukemia cells are present in the testicles at the end of Induction therapy, then radiation therapy to the testicles may be needed. These treatments are usually given 5 days/week for about 2 weeks.

Surgery: In general, ALL is not treated with surgery, although operations may need to be done to put in a central line or to perform biopsies.

Targeted therapy: For some types of ALL, new “targeted” therapies have been developed that are added to chemotherapy. Right now, this mainly applies to a rare type of ALL called “Philadelphia chromosome positive ALL.” In the future, such therapies may be available for more types of ALL.

Bone marrow (stem cell) transplant: Only a small percentage of children’s ALL cases are treated with bone marrow transplant at the time of initial diagnosis. This type of treatment is used more frequently to treat ALL that has relapsed one or more times.

Research Studies

The majority of children with cancer participate in research studies. This high rate of participation has been essential to improving the cure rates for children’s cancer.

Researchers design various studies to improve treatment and advance the understanding of cancer and its causes. Clinical trials are carefully reviewed and must be approved through a formal scientific process before anyone can be enrolled. If there is a research study “open” that your child is “eligible for,” you may be asked to allow your child to participate. It is also possible that your child will be asked to participate in more than one study.

Whether an individual is eligible for a particular study may depend on age, location of the cancer, the extent of the disease and other information. Researchers usually must limit their study to some of these characteristics to have a scientifically valid study. Further, researchers must follow exactly the same restrictions throughout the study.

If your child is eligible to participate in one or more study, your doctor will discuss these with you during an initial treatment conference (also called informed consent conference). The doctor will describe the study, potential risks of participation, and other information you need to decide whether or not you would like your child to participate in the study. You always have the choice to participate or not in research studies.

If you do choose to have your child participate in a study, you doctor will explain what type of information you will receive about the results of the study. The overall results of the research study will be published to inform the public and other researchers. No study will publish any information that identifies an individual.

Visit the Clinical Trials section of this website to learn more about the various kinds of research studies.

Last updated July, 2011

About Acute Lymphoblastic Leukemia
Just Diagnosed with Acute Lymphoblastic Leukemia
After Treatment of Acute Lymphoblastic Leukemia