Cancer starts when cells in the body begin to grow out of control. Cells in nearly any part of the body can become cancer, and can spread to other areas of the body. To learn more about how cancers start and spread, see What Is Cancer?

Acute lymphocytic leukemia (ALL), also called acute lymphoblastic leukemia, is a cancer that starts from the early version of white blood cells called lymphocytes in the bone marrow (the soft inner part of the bones, where new blood cells are made).

Leukemia cells usually invade the blood fairly quickly. They can then spread to other parts of the body, including the lymph nodes, liver, spleen, central nervous system (brain and spinal cord), and testicles (in males). Other types of cancer also can start in these organs and then spread to the bone marrow, but these cancers are not leukemia.

The term “acute” means that the leukemia can progress quickly, and if not treated, would probably be fatal within a few months. Lymphocytic means it develops from early (immature) forms of lymphocytes, a type of white blood cell. This is different from acute myeloid leukemia (AML), which develops in other blood cell types found in the bone marrow. For more information on AML, see Acute Myeloid Leukemia. 

Other types of cancer that start in lymphocytes are known as lymphomas (non-Hodgkin lymphoma or Hodgkin disease). The main difference between these types of cancers is that leukemias like ALL mainly affects the bone marrow and the blood, and may spread to other places, while lymphomas mainly affect the lymph nodes or other organs but may involve the bone marrow. Sometimes cancerous lymphocytes are found in both the bone marrow and lymph nodes when the cancer is first diagnosed, which can make it hard to tell if the cancer is leukemia or lymphoma. If more than 25% of the bone marrow is replaced by cancerous lymphocytes, the disease is usually considered leukemia. The size of lymph nodes is also important. The bigger they are, the more likely the disease will be considered a lymphoma. For more information on lymphomas, see Non-Hodgkin Lymphoma and Hodgkin Disease.

There are actually many types of leukemia. They differ based on what types of cells they start in, how quickly they grow, which people they affect, and how they are treated. To understand leukemia, it helps to know about the blood and lymph systems.

Normal bone marrow, blood, and lymphoid tissue

Bone marrow

Bone marrow is the soft inner part of some bones, such as the skull, shoulder blades, ribs, pelvis, and bones in the spine. The bone marrow is made up of a small number of blood stem cells, more mature blood-forming cells, fat cells, and supporting tissues that help cells grow.

Blood stem cells go through a series of changes to make new blood cells. During this process, the cells develop into 1 of the 3 main types of blood cell components:

• Red blood cells
• Platelets
• White blood cells (which include lymphocytes, granulocytes, and monocytes)

Red blood cells

Red blood cells carry oxygen from the lungs to all other tissues in the body, and take carbon dioxide back to the lungs to be removed.

Platelets

Platelets are actually cell fragments made by a type of bone marrow cell called a megakaryocyte. Platelets are important in plugging up holes in blood vessels caused by cuts or bruises.

White blood cells

White blood cells help the body fight infections.

Lymphocytes

These are the main cells that make up lymphoid tissue, a major part of the immune system. Lymphoid tissue is found in lymph nodes, the thymus, the spleen, the tonsils and adenoids, and is scattered throughout the digestive and respiratory systems and the bone marrow.

Lymphocytes develop from cells called lymphoblasts to become mature, infection-fighting cells. The 2 main types of lymphocytes are B lymphocytes (B cells) and T lymphocytes (T cells).

• B lymphocytes: B lymphocytes protect the body from invading germs by maturing into plasma cells, which make proteins called antibodies. The antibodies attach to the germs (bacteria, viruses, and fungi), which helps the immune system destroy them.
• T lymphocytes: There are several types of T cells, each with a special job. Some T cells can destroy germs directly, while others play a role in either boosting or slowing the activity of other immune system cells.

Acute lymphocytic leukemia develops from early forms of lymphocytes. It can start in either early B cells or T cells at different stages of maturity. This is discussed in How is acute lymphocytic leukemia classified?

Granulocytes

These are white blood cells that have granules in them, which are spots that can be seen under the microscope. These granules contain enzymes and other substances that can destroy germs, such as bacteria. The 3 types of granulocytes – neutrophils, basophils, and eosinophils – are distinguished by the size and color of their granules.

Monocytes

These white blood cells, which are related to granulocytes, also help protect the body against bacteria. After circulating in the bloodstream for about a day, monocytes enter body tissues to become macrophages, which can destroy some germs by surrounding and digesting them.

Development of leukemia

Any type of early blood-forming cell of the bone marrow can turn into a leukemia cell. Once this change happens, the leukemia cells will not mature normally. The leukemia cells could reproduce quickly, and might not die when they should. Instead they survive and build up in the bone marrow. Over time, these cells spill into the bloodstream and spread to other organs, where they can keep other cells from functioning normally.

Types of leukemia

There are 4 main types of leukemia:

• Acute myeloid (or myelogenous) leukemia (AML)
• Chronic myeloid (or myelogenous) leukemia (CML)
• Acute lymphocytic (or lymphoblastic) leukemia (ALL)
• Chronic lymphocytic leukemia (CLL)

Acute leukemia versus chronic leukemia

The first factor in classifying leukemia is whether most of the abnormal cells are mature (look like normal white blood cells) or immature (look more like stem cells).

Acute leukemia: In acute leukemia, the bone marrow cells cannot mature properly. Immature leukemia cells continue to reproduce and build up. Without treatment, most people with acute leukemia would live only a few months. Some types of acute leukemia respond well to treatment, and many patients can be cured. Other types of acute leukemia have a less favorable outlook.

Chronic leukemia: In chronic leukemia, the cells can mature partly but not completely. These cells may look fairly normal, but they generally do not fight infection as well as normal white blood cells do. They also live longer, build up, and crowd out normal cells. Chronic leukemias tend to progress over a longer period of time, and most people can live for many years. But chronic leukemias are generally harder to cure than acute leukemias.

Myeloid leukemia versus lymphocytic leukemia

The second factor in classifying leukemia is the type of bone marrow cells that are affected.

Myeloid leukemia: Leukemias that start in early forms of myeloid cells – the cells that make white blood cells (other than lymphocytes), red blood cells, or platelet-making cells (megakaryocytes) – are myeloid leukemias (also known as myelocytic, myelogenous, or non-lymphocytic leukemias).

Lymphocytic leukemia: Leukemias that start in immature forms of lymphocytes are called lymphocytic leukemias (also known as lymphoid or lymphoblastic leukemias).

The rest of this document focuses on acute lymphocytic leukemia (ALL) in adults. For information on ALL in children, see Childhood Leukemia. Chronic leukemias and acute myeloid leukemia of adults are discussed in other American Cancer Society documents.

Researchers are now studying the causes, diagnosis, supportive care, and treatment of acute lymphocytic leukemia (ALL) at many medical centers, university hospitals, and other institutions.

Genetics of leukemia

Scientists are making great progress in understanding how changes in a person’s DNA can cause normal bone marrow cells to develop into leukemia cells. A greater understanding of the genes (regions of the DNA) involved in certain translocations that often occur in ALL is providing insight into why these cells become abnormal. Doctors are now looking to learn how to use these changes to help them determine a person’s outlook and whether they should receive more or less intensive treatment.

As this information unfolds, it may also be used to develop newer targeted therapies against ALL. Drugs such as imatinib (Gleevec) and dasatinib (Sprycel) are examples of such treatments. They are now used in treating ALL patients whose leukemia cells have the Philadelphia chromosome.

Gene expression profiling

This new lab technique is being studied to help identify and classify different cancers. Instead of looking at single genes, this test uses a special technology to look at the patterns of many different genes in the cancer cells at the same time. This may add to the information that comes from the current lab tests.

This information may eventually allow more personalized treatment by predicting which chemo drugs are likely to be most effective for each patient. These tests are also being used to find previously unknown changes inside ALL cells to help guide researchers in developing new drugs.

Detecting minimal residual disease

Progress in understanding DNA changes in ALL has already provided a highly sensitive test for detecting minimal residual disease after treatment – when so few leukemia cells are present that they cannot be found by routine bone marrow tests.

The polymerase chain reaction (PCR) test can identify ALL cells based on their gene translocations or rearrangements. This test can find one leukemia cell among many thousands of normal cells. A PCR test can be used in determining how completely chemotherapy has destroyed the ALL cells.

Doctors are now trying to determine if patients with minimal residual disease will benefit from further or more intensive treatment.

Improving chemotherapy

Studies are in progress to find the most effective combination of chemotherapy (chemo) drugs while limiting unwanted side effects. This is especially important in older patients, who often have a harder time tolerating current treatments.

New chemo drugs are also being developed and tested. For example, clofarabine (Clolar^®) is approved to treat childhood ALL and shows promise in early studies of adults with this disease. Many other new drugs are also being studied.

Studies are also under way to determine whether patients with certain unfavorable prognostic features benefit from more intensive chemo, and whether some ALL patients with favorable prognostic factors might not need as much treatment.

The effectiveness of chemotherapy may be limited in some cases because the leukemia cells become resistant to it. Researchers are now looking at ways to prevent or reverse this resistance by using other drugs along with chemotherapy.

Stem cell transplants

Researchers continue to refine stem cell transplants to try to increase their effectiveness, reduce complications and determine which patients are likely to be helped by this treatment. Many studies are being done to try to help determine exactly when allogeneic, autologous, and mini-transplants might best be used.

Doctors are also studying donor leukocyte infusion in people who have already received an allogeneic transplant and who relapse. In this technique, the patient gets an infusion of white blood cells (leukocytes) from the same donor who contributed stem cells for the original transplant. The hope is that the cells will boost the new immune system and add to the graft-versus-leukemia effect. Early study results have been promising, but more research on this approach is needed.

Monoclonal antibodies

These drugs are man-made versions of immune system proteins (antibodies). They can be targeted to attach only to certain molecules, such as proteins on the surface of certain lymphocytes.

Some monoclonal antibodies, such as rituximab (Rituxan) and alemtuzumab (Campath), are already used to treat other blood disorders and are now being studied for use against ALL. Early results have been favorable, but it is still too early to know for sure.

Epratuzumab, a newer antibody, has also shown promise against ALL in early studies. Further studies are planned.

Another approach is to attach a chemo drug to a monoclonal antibody. The antibody serves as a homing device to bring the chemo drug to the cancer cell. One such drug, inotuzumab ozogamicin, has shown promise in treating ALL.

Studies of several other monoclonal antibodies to treat ALL are now under way as well.

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.

Problems caused by low blood cell counts

Most signs and symptoms of ALL result from 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:

• Feeling tired
• Feeling weak
• Feeling dizzy or lightheaded
• Shortness of breath
• Fever
• Infections that don’t go away or keep coming back
• Bruising easily
• Bleeding, such as frequent or severe nosebleeds and bleeding gums

General symptoms

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

• Weight loss
• Fever
• Night sweats
• Fatigue
• 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, causing them to enlarge. 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 they 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 and cause bone or joint pain.

Spread to other organs

Less often, ALL spreads to other organs:

• If ALL spreads to the brain and spinal cord it can cause headaches, weakness, seizures, vomiting, trouble with balance, facial numbness, or blurred vision.
• ALL may spread to the chest cavity, where it can cause fluid buildup and trouble breathing.
• Rarely, ALL may spread to the skin, eyes, testicles, 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, causing coughing or trouble breathing.

The American Cancer Society’s estimates for acute lymphocytic leukemia (ALL) in the United States for 2018 (including both children and adults) are:

• About 5,960 new cases of ALL (3,290 in males and 2,670 in females)
• About 1,470 deaths from ALL (830 in males and 640 in females)

The risk for developing ALL is highest in children younger than 5 years of age. The risk then declines slowly until the mid-20s, and begins to rise again slowly after age 50. Overall, about 4 of every 10 cases of ALL are in adults.

The average person’s lifetime risk of getting ALL is less than 1 in 1000. The risk is slightly higher in males than in females, and higher in whites than in African Americans.

Most cases of ALL occur in children, but most deaths from ALL occur in adults. Children may do better because of differences in childhood and adult ALL in the disease itself, differences in treatment (children’s bodies can often handle aggressive treatment better than adult’s), or some combination of these.

Visit the American Cancer Society’s Cancer Statistics Center for more key statistics.

A risk factor is something that affects 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 risk factors don’t tell us everything. 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. Even if a person has one or more risk factors and develops cancer, it is often very hard to know how much they might have contributed to the cancer.

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

Radiation exposure

Being exposed to high levels of radiation is a risk factor for both ALL and acute myeloid leukemia (AML). Japanese atomic bomb survivors had a greatly increased risk of developing acute leukemia, usually within 6 to 8 years after exposure.

Treating cancer with radiation therapy also increases the risk of leukemia, although AML is more often seen than ALL. The risk seems to be higher if chemotherapy and radiation are both used in treatment.

The possible risks of leukemia from being exposed to lower levels of radiation, such as from medical imaging tests (such as x-rays) are not well-known. Exposure of a fetus to radiation within the first months of development may carry an increased risk of leukemia, but the extent of the risk is not clear.

If there is an increased risk from lower levels of radiation it is likely to be small, but to be safe, most doctors try to limit a person’s exposure to radiation as much as possible.

Certain chemical exposures

The risk of ALL may be increased by exposure to certain chemotherapy drugs and certain chemicals, including benzene. Benzene is a solvent used in the rubber industry, oil refineries, chemical plants, shoe manufacturing, and gasoline-related industries, and is also present in cigarette smoke, as well as some glues, cleaning products, detergents, art supplies, and paint strippers. Chemical exposure is more strongly linked to an increased risk of AML than to ALL.

Certain viral infections

Infection with the human T-cell lymphoma/leukemia virus-1 (HTLV-1) can cause a rare type of T-cell acute lymphocytic leukemia. Most cases occur in Japan and the Caribbean area. This disease is not common in the United States.

In Africa, the Epstein-Barr virus (EBV) has been linked to Burkitt lymphoma, as well as to a form of acute lymphocytic leukemia. In the United States, EBV most often causes infectious mononucleosis (“mono”).

Inherited syndromes

Acute lymphocytic leukemia does not appear to be an inherited disease. It does not seem to run in families, so a person’s risk is not increased if a family member has the disease. But there are some inherited syndromes with genetic changes that seem to raise the risk of ALL. These include:

• Down syndrome
• Klinefelter syndrome
• Fanconi anemia
• Bloom syndrome
• Ataxia-telangiectasia
• Neurofibromatosis

Race/ethnicity

Acute lymphocytic leukemia is more common in whites than in African Americans, but the reasons for this are not clear.

Gender

Acute lymphocytic leukemia is slightly more common in males than in females. The reason for this is unknown.

Having an identical twin with ALL

Someone who has an identical twin who develops ALL in the first year of life has an increased risk of getting ALL.

Uncertain, unproven or controversial risk factors

Other factors that have been studied for a possible link to ALL include:

• Exposure to electromagnetic fields (such as living near power lines or using cell phones)
• Workplace exposure to diesel, gasoline, pesticides, and certain other chemicals
• Smoking
• Exposure to hair dyes

So far, none of these factors has been linked conclusively to ALL. Research in these areas continues.

Some people with acute lymphocytic leukemia (ALL) have one or more of the known risk factors (see What are the risk factors for acute lymphocytic leukemia?), but most do not. The cause of their cancer remains unknown at this time. Even when a person has one or more risk factors, there is no way to tell whether it actually caused the cancer.

During the past few years, scientists have made great progress in understanding how certain changes in DNA can cause normal bone marrow cells to become leukemia cells. Normal human cells grow and function based mainly on the information contained in each cell’s chromosomes. Chromosomes are like bundles of long molecules of DNA in each cell. DNA is the chemical that makes up our genes – the instructions for how our cells function. We look like our parents because they are the source of our DNA. But our genes affect more than the way we look.

Some genes contain instructions for controlling when our cells grow and divide. Certain genes that help cells grow and divide are called oncogenes. Others that slow down cell growth and division or cause them to die at the right time are called tumor suppressor genes.

Each time a cell prepares to divide into 2 new cells, it must make a new copy of the DNA in its chromosomes. This process is not perfect, and errors can occur that may affect genes within the DNA. Cancers can be caused by DNA mutations (changes) that turn on oncogenes or turn off tumor suppressor genes.

Translocations are the most common type of DNA change that can lead to leukemia. Human DNA is packaged in 23 pairs of chromosomes. A translocation means that DNA from one chromosome breaks off and becomes attached to a different chromosome. The point on the chromosome where the break occurs can affect genes – for example, it can turn on oncogenes or turn off genes that would normally help a cell mature.

The most common translocation in ALL in adults is known as the Philadelphia chromosome, which is a swap of DNA between chromosomes 9 and 22, abbreviated as t(9;22). It occurs in about 1 out of 4 adult ALL cases. Other, less common translocations are those between chromosomes 4 and 11, t(4;11), or 8 and 14, t(8;14).

Other chromosome changes such as deletions (the loss of part of a chromosome) and inversions (the rearrangement of the DNA within part of a chromosome) can also affect the development of ALL, although they are less common. In many cases of ALL, the gene changes that lead to the leukemia are not known.

Doctors are trying to figure out why these changes occur and how each of them might lead to leukemia. Not all cases of ALL have the same chromosome changes. Some changes are more common than others, and some seem to have more of an effect on a person’s prognosis (outlook) than others.

Some people with certain types of cancer have inherited DNA mutations from a parent. These changes increase their risk for the disease. But ALL is very rarely caused by one of these inherited mutations.

Usually DNA mutations related to ALL occur during the person’s lifetime rather than having been inherited before birth. They may result from exposure to radiation or cancer-causing chemicals, but in most cases the reason they occur is not known.

For many types of cancers, diagnosis at the earliest possible stage makes treatment much more effective. The American Cancer Society recommends screening tests for early detection of certain cancers in people without any symptoms.

But at this time there are no special tests recommended to detect acute lymphocytic leukemia (ALL) early. The best way to find leukemia early is to report any possible signs or symptoms of leukemia (see Signs and symptoms of acute lymphoblastic leukemia) to the doctor right away.

Some people are known to have a higher risk of ALL (or other leukemias) because of an inherited disorder such as Down syndrome. Most doctors recommend that these people have careful, regular medical checkups. The risk of leukemia, although greater than in the general population, is still very low for most of these syndromes.

If the leukemia keeps growing or comes back after one kind of treatment, it is possible that another treatment plan might still cure it, or at least treat it enough to help you live longer and feel better. But when a person has tried many different treatments and the leukemia doesn’t go away, it tends to become resistant to all treatment. If this happens, it’s important to weigh the possible limited benefits of a new treatment against the possible downsides. Everyone has their own way of looking at this.

This is likely to be the hardest part of your battle with cancer – when you have been through many medical treatments and nothing’s working anymore. Your doctor may offer you new options, but at some point you may need to consider that treatment is not likely to improve your health or change your outcome or survival.

If you want to continue to get treatment for as long as you can, you need to think about the odds of treatment having any benefit and how this compares to the possible risks and side effects. In many cases, your doctor can estimate how likely it is the leukemia will respond to treatment you are considering. For instance, the doctor may say that more chemo or radiation might have about a 1% chance of working. Some people are still tempted to try this. But it is important to think about and understand your reasons for choosing this plan.

No matter what you decide to do, you need to feel as good as you can. Make sure you are asking for and getting treatment for any symptoms you might have, such as nausea or pain. This type of treatment is called palliative care.

Palliative care helps relieve symptoms, but is not expected to cure the disease. It can be given along with cancer treatment, or can even be cancer treatment. The difference is its purpose – the main purpose of palliative care is to improve the quality of your life, or help you feel as good as you can for as long as you can. Sometimes this means using drugs to help with symptoms like pain or nausea. Often, in leukemia, palliative care includes transfusions of red blood cells to help you feel stronger. Sometimes, though, the treatments used to control symptoms are the same as those used to treat cancer. For instance, radiation might be used to help relieve bone pain caused by cancer that has spread to the bones. Or chemo might be used to help shrink a tumor and keep it from blocking the bowels. But this is not the same as treatment to try to cure the cancer.

At some point, you may benefit from hospice care. This is special care that treats the person rather than the disease; it focuses on quality rather than length of life. Most of the time, it is given at home. Your cancer may be causing problems that need to be managed, and hospice focuses on your comfort. You should know that while getting hospice care often means the end of treatments such as chemo and radiation, it doesn’t mean you can’t have treatment for the problems caused by the cancer or other health conditions. In hospice the focus of your care is on living life as fully as possible and feeling as well as you can at this difficult time. You can learn more in Hospice Care and Nearing the End of Life.

Staying hopeful is important, too. Your hope for a cure may not be as bright, but there is still hope for good times with family and friends – times that are filled with happiness and meaning. Pausing at this time in your cancer treatment gives you a chance to refocus on the most important things in your life. Now is the time to do some things you’ve always wanted to do and to stop doing the things you no longer want to do. Though the cancer may be beyond your control, there are still choices you can make.

For some people with acute lymphocytic leukemia (ALL), treatment may get rid of the cancer. Completing treatment can be both stressful and exciting. You may be relieved to finish treatment, but find it hard not to worry about the leukemia coming back. (When cancer comes back after treatment, it is called recurrence.) This is a very common concern in people who have had cancer.

It may take a while before your fears lessen. But it may help to know that many cancer survivors have learned to live with this uncertainty and are living full lives. See Understanding Recurrence, for more detailed information on this.

For some people, the leukemia may not go away completely. These people may get regular treatments with chemotherapy, radiation therapy, or other therapies to help keep the leukemia in check for as long as possible. Learning to live with cancer that does not go away can be difficult and very stressful. It has its own type of uncertainty. See Managing Cancer as a Chronic Illness for more about this.

Follow-up care

Treatment for ALL typically lasts for years. If you have completed treatment, your doctors will still want to watch you closely. It’s very important to go to all of your follow-up appointments. During these visits, your doctors will ask questions about any problems you may have and might do exams and lab tests or imaging tests to look for signs of leukemia or treatment side effects. Almost any cancer treatment can have side effects. Some may last for a few weeks to months, but others can last the rest of your life. This is the time for you to talk to your cancer care team about any changes or problems you notice and any questions or concerns you have.

It’s also important to keep health insurance. Tests and doctor visits cost a lot, and even though no one wants to think of their cancer coming back, this could happen.

If a relapse occurs, it is usually while the patient is being treated or shortly after they have finished chemotherapy. If this happens, treatment would be as described in What If the Leukemia Doesn’t Respond or Comes Back After Treatment? It is unusual for ALL to return if there are still no signs of the disease within 5 years after treatment.

For more general information on dealing with a recurrence, see Coping With Cancer Recurrence.

Seeing a new doctor

At some point after your cancer diagnosis and treatment, you may find yourself seeing a new doctor who does not know all the details of your medical history. It is important that you be able to give your new doctor the details of your diagnosis and treatment. Gathering these details soon after treatment may be easier than trying to get them at some point in the future. Make sure you have this information handy:

• A copy of your pathology report(s) from any biopsies or surgeries
• If you had surgery, a copy of your operative report(s)
• If you stayed in the hospital, a copy of the discharge summary that doctors prepare when patients are sent home
• If you had radiation therapy, a copy of your treatment summary
• If you had chemotherapy or other medicines (like targeted therapy), a list of your drugs, drug doses, and when you took them

The doctor may want copies of this information for his records, but always keep copies for yourself.