Acute Lymphoblastic Leukemia Treatment

Acute lymphocytic leukemia (ALL) is a type of cancer of the blood and bone marrow — the spongy tissue inside bones where blood cells are made.

The word “acute" in acute lymphocytic leukemia comes from the fact that the disease progresses rapidly and creates immature blood cells, rather than mature ones. The word “lymphocytic" in acute lymphocytic leukemia refers to the white blood cells called lymphocytes, which ALL affects. Acute lymphocytic leukemia is also known as acute lymphoblastic leukemia.

Acute lymphocytic leukemia is the most common type of cancer in children, and treatments result in a good chance for a cure. Acute lymphocytic leukemia can also occur in adults, though the chance of a cure is greatly reduced.

Doctors classify acute lymphoblastic leukemia (ALL) into subtypes by using various tests. It's important to get an accurate diagnosis since your subtype plays a large part in deciding the type of treatment you'll receive.

Common testing used to classify ALL subtypes include immunophenotyping and cytogenetic analysis. Some of these tests may be repeated during and after therapy to measure the effects of treatment. Your doctor must identify the immunophenotype and any abnormalities in your chromosomes to determine:

1. The intensity of the drug combination needed for your treatment.
2. The length of time you'll need to be in treatment.

The two main ALL subtypes, B-cell ALL and T-cell ALL, are determined by immunophenotyping. Most people with ALL have the B-cell type. Most cases of B-cell ALL begin in a cell called a precursor B-cell.

Doctors use the following terms to further describe ALL sub types:

Pre-B-cell ALL

In between 75-80% of adult cases, ALL arises in B-lymphocytes in the early stages of development in the bone marrow. The disease is therefore called precursor B-cell ALL or Pre-B-cell ALL.

B-cell ALL

B-cell ALL arises in more mature developing lymphocytes. This type of ALL is less common accounting for around 3-5% of all adult cases. B-cell ALL is sometimes called Burkitt-like or Burkitt type ALL. People diagnosed with B-cell ALL are commonly treated with similar drugs to those used to treat Burkitt lymphoma.

T-cell ALL

In around 20-25% of cases, ALL arises in developing T-cells. This type of ALL can be further classified as early, mid or late, depending on the maturity of the affected cell. T-cell ALL commonly presents with a high white blood cell count and involvement of the central nervous system at diagnosis.

Acute lymphocytic leukemia (ALL) can cause many different signs and symptoms. Most of these occur in all kinds of ALL, but some are more common with certain subtypes of ALL.

Symptoms caused by low numbers of blood cells

Most signs and symptoms of ALL are the result of shortages of normal blood cells, which happen when the leukemia cells crowd out the normal blood-making cells in the bone marrow. These shortages show up on blood tests, but they can also cause symptoms, including:

1. Feeling tired
2. Feeling weak
3. Feeling dizzy or lightheaded
4. Shortness of breath
5. Pale skin
6. Infections that don’t go away or keep coming back
7. Bruises (or small red or purple spots) on the skin
8. Bleeding, such as frequent or severe nosebleeds, bleeding gums, or heavy menstrual bleeding in women

General symptoms

Patients with ALL also often have several non-specific symptoms. These can include:

1. Weight loss
2. Fever
3. Night sweats
4. Loss of appetite

Of course, these are not just symptoms of ALL and are more often caused by something other than leukemia.

Swelling in the abdomen

Leukemia cells may build up in the liver and spleen, making them larger. This might be noticed as a fullness or swelling of the belly, or feeling full after eating only a small amount. The lower ribs usually cover these organs, but when the organs are enlarged the doctor can feel them.

Enlarged lymph nodes

ALL that has spread to lymph nodes close to the surface of the body (such as on the sides of the neck, in the groin, or in underarm areas), might be noticed as lumps under the skin. Lymph nodes inside the chest or abdomen may also swell, but these can be detected only by imaging tests such as CT or MRI scans.

Bone or joint pain

Sometimes leukemia cells build up near the surface of the bone or inside the joint, which can lead to bone or joint pain.

Spread to other organs

Less often, ALL spreads to other organs:

1. If ALL spreads to the brain and spinal cord it can cause headaches, weakness, seizures, vomiting, trouble with balance, facial muscle weakness or numbness, or blurred vision.
2. ALL may spread inside the chest, where it can cause fluid buildup and trouble breathing.
3. Rarely, ALL may spread to the skin, eyes, testicles, ovaries, kidneys, or other organs.

Symptoms from an enlarged thymus

The T-cell subtype of ALL often affects the thymus, which is a small organ in the middle of the chest behind the sternum (breastbone) and in front of the trachea (windpipe). An enlarged thymus can press on the trachea, which can lead to coughing or trouble breathing.

The superior vena cava (SVC), a large vein that carries blood from the head and arms back to the heart, passes next to the thymus. If the thymus is enlarged, it may press on the SVC, causing the blood to “back up” in the veins. This is known as SVC syndrome. It can cause:

1. Swelling in the face, neck, arms, and upper chest (sometimes with a bluish-red color)
2. Headaches
3. Dizziness
4. Change in consciousness if it affects the brain

The SVC syndrome can be life-threatening, and needs to be treated right away.

Acute lymphocytic leukemia occurs when a bone marrow cell develops errors in its DNA. The errors tell the cell to continue growing and dividing, when a healthy cell would normally stop dividing and eventually die. When this happens, blood cell production becomes abnormal. The bone marrow produces immature cells that develop into leukemic white blood cells called lymphoblasts. These abnormal cells are unable to function properly, and they can build up and crowd out healthy cells.

It's not clear what causes the DNA mutations that can lead to acute lymphocytic leukemia. But doctors have found that most cases of acute lymphocytic leukemia aren't inherited.

A risk factor is something that increases your chance of getting a disease such as cancer. Some risk factors, like smoking, can be controlled. Others, like a person’s age or family history, can’t be changed.

But having a risk factor, or even several risk factors, does not mean that you will definitely get the disease. And many people who get the disease may have few or no known risk factors.

There are only a handful of known risk factors for acute lymphocytic leukemia (ALL).

Previous cancer treatment: Children and adults who've had certain types of chemotherapy and radiation therapy for other kinds of cancer may have an increased risk of developing acute lymphocytic leukemia.

Exposure to radiation: People exposed to very high levels of radiation, such as survivors of a nuclear reactor accident, have an increased risk of developing acute lymphocytic leukemia.

Genetic disorders: Certain genetic disorders, such as Down syndrome, are associated with an increased risk of acute lymphocytic leukemia.

Having a brother or sister with ALL: People who have a sibling, including a twin, with acute lymphocytic leukemia have an increased risk of ALL.

Certain signs and symptoms can suggest that a person might have acute lymphocytic leukemia (ALL), but tests are needed to confirm the diagnosis.

Blood tests: Blood tests may reveal too many white blood cells, not enough red blood cells and not enough platelets. A blood test may also show the presence of blast cells — immature cells normally found in the bone marrow.

Bone marrow test: During bone marrow aspiration, a needle is used to remove a sample of bone marrow from the hip bone or breastbone. The sample is sent to a lab for testing to look for leukemia cells.

Doctors in the lab will classify blood cells into specific types based on their size, shape and other genetic or molecular features. They also look for certain changes in the cancer cells and determine whether the leukemia cells began from the B lymphocytes or T lymphocytes. This information helps your doctor develop a treatment plan.

Imaging tests: Imaging tests such as an X-ray, computerized tomography (CT) scan or ultrasound scan may help determine whether cancer has spread to the brain and spinal cord or other parts of the body.

Spinal fluid test: A lumbar puncture test, also called a spinal tap, may be used to collect a sample of spinal fluid — the fluid that surrounds the brain and spinal cord. The sample is tested to see whether cancer cells have spread to the spinal fluid.

Because it progresses quickly, treatment needs to begin soon after ALL is diagnosed. The type of treatment used will depend on a number of factors including the sub-type of ALL, the genetic make-up of the leukaemic cells, your age and your general health.

In general, treatment for acute lymphocytic leukemia falls into separate phases:

Induction therapy: The purpose of the first phase of treatment is to kill most of the leukemia cells in the blood and bone marrow and to restore normal blood cell production.

Consolidation therapy: Also called post-remission therapy, this phase of treatment is aimed at destroying any remaining leukemia in the body, such as in the brain or spinal cord.

Maintenance therapy: The third phase of treatment prevents leukemia cells from regrowing. The treatments used in this stage are often given at much lower doses over a long period of time, often years.

Preventive treatment to the spinal cord: During each phase of therapy, people with acute lymphocytic leukemia may receive additional treatment to kill leukemia cells located in the central nervous system. In this type of treatment, chemotherapy drugs are often injected directly into the fluid that covers the spinal cord.

Depending on your situation, the phases of treatment for acute lymphocytic leukemia can span two to three years.

Treatments may include:

Chemotherapy: Chemotherapy, which uses drugs to kill cancer cells, is typically used as an induction therapy for children and adults with acute lymphocytic leukemia. Chemotherapy drugs can also be used in the consolidation and maintenance phases.

Targeted therapy: Targeted drugs attack specific abnormalities present in cancer cells that help them grow and thrive.

A certain abnormality called the Philadelphia chromosome is found in some people with acute lymphocytic leukemia. For these people, targeted drugs may be used to attack cells that contain that abnormality. Targeted therapy may be used during or after chemotherapy.

Radiation therapy: Radiation therapy uses high-powered beams, such as X-rays or protons, to kill cancer cells. If the cancer cells have spread to the central nervous system, your doctor may recommend radiation therapy.

Bone marrow transplant: A bone marrow transplant, also known as a stem cell transplant, may be used as consolidation therapy in people at high risk of relapse or for treating relapse when it occurs. This procedure allows someone with leukemia to re-establish healthy bone marrow by replacing leukemic bone marrow with leukemia-free marrow from a healthy person.

A bone marrow transplant begins with high doses of chemotherapy or radiation to destroy any leukemia-producing bone marrow. The marrow is then replaced by bone marrow from a compatible donor (allogeneic transplant).