What You Need To Know About Leukemia

What You Need To Know About Leukemia
Source: NIH Publication No. 95-3775

Each year, nearly 27,000 adults and more than 2,000 children in the United States learn that they have leukemia. This National Cancer Institute (NCI) booklet describes the symptoms of leukemia and explains how this disease is diagnosed and treated. It also has information to help you deal with leukemia if it affects you or someone you know.

Words that may be new to readers appear in italics. Definitions of these words and other terms related to leukemia can be found in the Dictionary. For some words, a “sounds-like” spelling is also given.

Other NCI booklets are listed in the Other Booklets section. Our materials cannot answer every question you may have about leukemia. They cannot take the place of talks with doctors, nurses, and other members of the health care team. We hope our information will help with those talks.

Our knowledge about leukemia and how to treat it keeps increasing. For up-to-date information or to order this publication, call the NCI-supported Cancer Information Service (CIS) toll free at 1-800-4-CANCER (1-800-422-6237).

What Is Leukemia?
Leukemia is a type of cancer. Cancer is a group of more than 100 diseases that have two important things in common. One is that certain cells in the body become abnormal. Another is that the body keeps producing large numbers of these abnormal cells.

Leukemia is cancer of the blood cells. To understand leukemia, it is helpful to know about normal blood cells and what happens to them when leukemia develops.

Normal Blood Cells
The blood is made up of fluid called plasma and three types of cells. Each type has special functions.

White blood cells (also called WBCs or leukocytes) help the body fight infections and other diseases.

Red blood cells (also called RBCs or erythrocytes) carry oxygen from the lungs to the body’s tissues and take carbon dioxide from the tissues back to the lungs. The red blood cells give blood its color.

Platelets (also called thrombocytes) help form blood clots that control bleeding.

Blood cells are formed in the bone marrow, the soft, spongy center of bones. New(immature) blood cells are called blasts. Some blasts stay in the marrow to mature. Some travel to other parts of the body to mature.

Normally, blood cells are produced in an orderly, controlled way, as the body needs them. This process helps keep us healthy.

Leukemia Cells
When leukemia develops, the body produces large numbers of abnormal blood cells. In most types of leukemia, the abnormal cells are white blood cells. The leukemia cells usually look different from normal blood cells, and they do not function properly.

Types of Leukemia
There are several types of leukemia. They are grouped in two ways. One way is by how quickly the disease develops and gets worse. The other way is by the type of blood cell that is affected.

Leukemia is either acute or chronic. In acute leukemia, the abnormal blood cells are blasts that remain very immature and cannot carry out their normal functions. The number of blasts increases rapidly, and the disease gets worse quickly. In chronic leukemia, some blast cells are present, but in general, these cells are more mature and can carry out some of their normal functions. Also, the number of blasts increases less rapidly than in acute leukemia. As a result, chronic leukemia gets worse gradually.

Leukemia can arise in either of the two main types of white blood cells — lymphoid cells or myeloid cells. When leukemia affects lymphoid cells, it is called lymphocytic leukemia. When myeloid cells are affected, the disease is called myeloid or myelogenous leukemia.

These are the most common types of leukemia:

Acute lymphocytic leukemia (ALL) is the most common type of leukemia in young children. This disease also affects adults, especially those age 65 and older.

Acute myeloid leukemia (AML) occurs in both adults and children. This type of leukemia is sometimes called acute nonlymphocytic leukemia (ANLL).

Chronic lymphocytic leukemia (CLL) most often affects adults over the age of 55. It sometimes occurs in younger adults, but it almost never affects children.

Chronic myeloid leukemia (CML) occurs mainly in adults. A very small number of children also develop this disease.

Hairy cell leukemia is an uncommon type of chronic leukemia. This and other uncommon types of leukemia are not discussed in this booklet. The Cancer Information Service can supply information about them.

Leukemia cells are abnormal cells that cannot do what normal blood cells do. They cannot help the body fight infections. For this reason, people with leukemia often get infections and have fevers.

Also, people with leukemia often have less than the normal amount of healthy red blood cells and platelets. As a result, there are not enough red blood cells to carry oxygen through the body. With this condition, called anemia, patients may look pale and feel weak and tired. When there are not enough platelets, patients bleed and bruise easily.

Like all blood cells, leukemia cells travel through the body. Depending on the number of abnormal cells and where these cells collect, patients with leukemia may have a number of symptoms.

In acute leukemia, symptoms appear and get worse quickly. People with this disease go to their doctor because they feel sick. In chronic leukemia, symptoms may not appear for a long time; when symptoms do appear, they generally are mild at first and get worse gradually. Doctors often find chronic leukemia during a routine checkup — before there are any symptoms.

These are some of the common symptoms of leukemia:

Fever, chills, and other flu-like symptoms;

Weakness and fatigue;

Frequent infections;

Loss of appetite and/or weight;

Swollen or tender lymph nodes, liver, or spleen;

Easy bleeding or bruising;

Tiny red spots (called petechiae) under the skin;

Swollen or bleeding gums;

Sweating, especially at night; and/or

Bone or joint pain.

In acute leukemia, the abnormal cells may collect in the brain or spinal cord (also called the central nervous system or CNS). The result may be headaches, vomiting, confusion, loss of muscle control, and seizures. Leukemia cells also can collect in the testicles and cause swelling. Also, some patients develop sores in the eyes or on the skin. Leukemia also can affect the digestive tract, kidneys, lungs, or other parts of the body.

In chronic leukemia, the abnormal blood cells may gradually collect in various parts of the body. Chronic leukemia may affect the skin, central nervous system, digestive tract, kidneys, and testicles.

To find the cause of a person’s symptoms, the doctor asks about the patient’s medical history and does a physical exam. In addition to checking general signs of health, the doctor feels for swelling in the liver; the spleen; and the lymph nodes under the arms, in the groin, and in the neck.

Blood tests also help in the diagnosis. A sample of blood is examined under a microscope to see what the cells look like and to determine the number of mature cells and blasts. Although blood tests may reveal that a patient has leukemia, they may not show what type of leukemia it is.

To check further for leukemia cells or to tell what type of leukemia a patient has, a hematologist, oncologist, or pathologist examines a sample of bone marrow under a microscope. The doctor withdraws the sample by inserting a needle into a large bone (usually the hip) and removing a small amount of liquid bone marrow. This procedure is called bone marrow aspiration. A bone marrow biopsy is performed with a larger needle and removes a small piece of bone and bone marrow.

If leukemia cells are found in the bone marrow sample, the patient’s doctor orders other tests to find out the extent of the disease. A spinal tap (lumbar puncture) checks for leukemia cells in the fluid that fills the spaces in and around the brain and spinal cord (cerebrospinal fluid). Chest x-rays can reveal signs of disease in the chest.

Treatment for leukemia is complex. It varies with the type of leukemia and is not the same for all patients. The doctor plans the treatment to fit each patient’s needs. The treatment depends not only on the type of leukemia, but also on certain features of the leukemia cells, the extent of the disease, and whether the leukemia has been treated before. It also depends on the patient’s age, symptoms, and general health.

Whenever possible, patients should be treated at a medical center that has doctors who have experience in treating leukemia. If this is not possible, the patient’s doctor should discuss the treatment plan with a specialist at such a center. Also, patients and their doctors can call the Cancer Information Service to request up-to-date treatment information from the National Cancer Institute’s PDQ® database.

Acute leukemia needs to be treated right away. The goal of treatment is to bring about a remission. Then, when there is no evidence of the disease, more therapy may be given to prevent a relapse. Many people with acute leukemia can be cured.

Chronic leukemia patients who do not have symptoms may not require immediate treatment. However, they should have frequent checkups so the doctor can see whether the disease is progressing. When treatment is needed, it can often control the disease and its symptoms. However, chronic leukemia can seldom be cured.

Many patients and their families want to learn all they can about leukemia and the treatment choices so they can take an active part in decisions about medical care. The doctor is the best person to answer these questions. When discussing treatment, the patient (or, in the case of a child, the patient’s family) may want to talk with the doctor about research studies of new treatment methods. Such studies, called clinical trials, are designed to improve cancer treatment. More information about clinical trials is in the Clinical Trials section.

When a person is diagnosed with leukemia, shock and stress are natural reactions. These feelings may make it difficult to think of every question to ask the doctor. Also, patients may find it hard to remember everything the doctor says.

Often, it helps to make a list of questions to ask the doctor. Taking notes or, if the doctor agrees, using a tape recorder can make it easier to remember the answers. Some people find that it also helps to have a family member or friend with them — to take part in the discussion, to take notes, or just to listen. Patients do not need to ask all their questions or remember all the answers at one time. They will have other chances for the doctor to explain things that are not clear and to ask for more information.

Here are some questions patients and their families may want to ask the doctor before treatment begins:

What type of leukemia is it?

What are the treatment choices? Which do you recommend? Why?

Would a clinical trial be appropriate?

What are the expected benefits of each kind of treatment?

What are the risks and possible side effects of each treatment?

If I have pain, how will you help me?

Will I have to change my normal activities?

How long will treatment last?

What is the treatment likely to cost? How can I find out what my insurance will cover?

Getting a Second Opinion
Sometimes it is helpful to have a second opinion about the diagnosis and treatment plan. (Many insurance companies provide coverage for a second opinion.) There are a number of ways to find a doctor who can give a second opinion:

The patient’s doctor may be able to suggest a doctor who specializes in adult or childhood leukemia. Doctors who treat adult leukemia are oncologists and hematologists. Pediatric oncologists and hematologists treat childhood leukemia.

The Cancer Information Service, at 1-800-4-CANCER, can tell callers about cancer centers and other treatment facilities in their area, including programs that are supported by the National Cancer Institute.

Patients can get the names of specialists from their local medical society, a nearby hospital, or a medical school.

Methods of Treatment
Most patients with leukemia are treated with chemotherapy. Some also may have radiation therapy and/or bone marrow transplantation (BMT) or biological therapy. In some cases, surgery to remove the spleen (an operation called a splenectomy) may be part of the treatment plan.

Chemotherapy is the use of drugs to kill cancer cells. Depending on the type of leukemia, patients may receive a single drug or a combination of two or more drugs.

Some anticancer drugs can be taken by mouth. Most are given by IV injection (injected into a vein). Often, patients who need to have many IV treatments receive the drugs through a catheter.

One end of this thin, flexible tube is placed in a large vein, often in the upper chest. Drugs are injected into the catheter, rather than directly into a vein, to avoid the discomfort of repeated injections and injury to the skin.

Anticancer drugs given by IV injection or taken by mouth enter the bloodstream and affect leukemia cells in most parts of the body. However, the drugs often do not reach cells in the central nervous system because they are stopped by the blood-brain barrier. This protective barrier is formed by a network of blood vessels that filter blood going to the brain and spinal cord. To reach leukemia cells in the central nervous system, doctors use intrathecal chemotherapy. In this type of treatment, anticancer drugs are injected directly into the cerebrospinal fluid.

Intrathecal chemotherapy can be given in two ways. Some patients receive the drugs by injection into the lower part of the spinal column. Others, especially children, receive intrathecal chemotherapy through a special type of catheter called an Ommaya reservoir. This device is placed under the scalp, where it provides a pathway to the cerebrospinal fluid. Injecting anticancer drugs into the reservoir instead of into the spinal column can make intrathecal chemotherapy easier and more comfortable for the patient.

Chemotherapy is given in cycles: a treatment period followed by a recovery period, then another treatment period, and so on. In some cases, the patient has chemotherapy as an outpatient at the hospital, at the doctor’s office, or at home. However, depending on which drugs are given and the patient’s general health, a hospital stay may be necessary.

Here are some questions patients and their families may want to ask the doctor before starting chemotherapy:

What drugs will be used?

When will the treatments begin? How often will they be given? When will they end?

Will I have to stay in the hospital?

How will we know whether the drugs are working?

What side effects occur during treatment? How long do the side effects last? What can be done to manage them?

Can these drugs cause side effects later on?

Radiation therapy is used along with chemotherapy for some kinds of leukemia. Radiation therapy (also called Radiotherapy) uses high-energy rays to damage cancer cells and stop them from growing. The radiation comes from a large machine.

Radiation therapy for leukemia may be given in two ways. For some patients, the doctor may direct the radiation to one specific area of the body where there is a collection of leukemia cells, such as the spleen or testicles. Other patients may receive radiation that is directed to the whole body. This type of radiation therapy, called total-body irradiation, usually is given before a bone marrow transplant.

Here are some questions patients and their families may want to ask the doctor before having radiation therapy:

When will the treatments begin? How often are they given? When will they end?

Can normal activities be continued?

How will we know if the treatment is working?

What side effects can be expected? How long will they last? What can be done about them?

Can radiation therapy cause side effects later on?

Bone marrow transplantation also may be used for some patients. The patient’s leukemia-producing bone marrow is destroyed by high doses of drugs and radiation and is then replaced by healthy bone marrow. The healthy bone marrow may come from a donor, or it may be marrow that has been removed from the patient and stored before the high-dose treatment. If the patient’s own bone marrow is used, it may first be treated outside the body to remove leukemia cells. Patients who have a bone marrow transplant usually stay in the hospital for several weeks. Until the transplanted bone marrow begins to produce enough white blood cells, patients have to be carefully protected from infection.

Here are some questions patients and their families may want to ask the doctor about bone marrow transplantation:

What are the benefits of this treatment?

What are the risks and side effects? What can be done about them?

How long will I be in the hospital? What care will be needed after I leave the hospital?

What changes in normal activities will be necessary?

How will we know if the treatment is working?

Biological therapy involves treatment with substances that affect the immune system’s response to cancer. Interferon is a form of biological therapy that is used against some types of leukemia.

Here are some questions patients and their families may want to ask the doctor before starting biological therapy:

What kind of treatment will be used?

What side effects can be expected? How long do the side effects last? What can be done to manage them?

How will we know whether the treatment is working?

Clinical Trials
Many patients with leukemia take part in clinical trials (treatment studies). Clinical trials help doctors find out whether a new treatment is both safe and effective. They also help doctors answer questions about how the treatment works and what side effects it causes.

Patients who take part in studies may be among the first to receive treatments that have shown promise in research. In many studies, some of the patients receive the new treatment, while others receive standard treatment so that doctors can compare different treatments. Patients who take part in a trial make an important contribution to medical science. Although these patients take certain risks, they may have the first chance to benefit from improved treatment methods.

Doctors are studying new treatments for all types of leukemia. They are working on new drugs, new drug combinations, and new schedules of chemotherapy. They also are studying ways to improve bone marrow transplantation.

Many clinical trials involve various forms of biological therapy. Interleukins and colony-stimulating factors are forms of biological therapy being studied to treat leukemia. Doctors also are studying ways to use monoclonal antibodies in the treatment of leukemia. Often biological therapy is combined with chemotherapy or bone marrow transplantation.

Patients with leukemia (or their families) should talk with the doctor if they are interested in taking part in a clinical trial. They may want to read Taking Part in Clinical Trials: What Cancer Patients Need To Know, which explains some of the possible benefits and risks of treatment studies.

One way to learn about clinical trials is through PDQ, a computerized resource developed by the National Cancer Institute. PDQ contains information about cancer treatment and about clinical trials in progress throughout the country. The Cancer Information Service can provide PDQ information to doctors, patients, and the public.

Supportive Care
Leukemia and its treatment can cause a number of complications and side effects. Patients receive supportive care to prevent or control these problems and to improve their comfort and quality of life during treatment.

Because leukemia patients get infections very easily, they may receive antibiotics and other drugs to help protect them from infections. They are often advised to stay out of crowds and away from people with colds and other infectious diseases. If an infection develops, it can be serious and should be treated promptly. Patients may need to stay in the hospital to treat the infection.

Anemia and bleeding are other problems that often require supportive care. Transfusions of red blood cells may be given to help reduce the shortness of breath and fatigue that anemia can cause. Platelet transfusions can help reduce the risk of serious bleeding.

Dental care also is very important. Leukemia and chemotherapy can make the mouth sensitive, easily infected, and likely to bleed. Doctors often advise patients to have a complete dental exam before treatment begins. Dentists can show patients how to keep their mouth clean and healthy during treatment.

Side Effects of Treatment
It is hard to limit the effects of therapy so that only leukemia cells are destroyed. Because treatment also damages healthy cells and tissues, it causes side effects.

The side effects of cancer treatment vary. They depend mainly on the type and extent of the treatment. Also, each person reacts differently. Side effects may even be different from one treatment to the next. Doctors try to plan the patient’s therapy to keep side effects to a minimum.

Doctors and nurses can explain the side effects of treatment and can suggest medicine, diet changes, or other ways to deal with them. The National Cancer Institute booklets Chemotherapy and You and Radiation Therapy and You also have helpful information about cancer treatment and coping with side effects.

The side effects of chemotherapy depend mainly on the drugs the patient receives. In addition, as with other types of treatment, side effects may vary from person to person. Generally, anticancer drugs affect dividing cells. Cancer cells divide more often than healthy cells and are more likely to be affected by chemotherapy. Still, some healthy cells also may be damaged. Healthy cells that divide often, including blood cells, cells in hair roots, and cells in the digestive tract, are likely to be damaged. When chemotherapy affects healthy cells, it may lower patients’ resistance to infection, and patients may have less energy and may bruise or bleed easily. They may lose their hair. The also may have nausea, vomiting, and mouth sores. Most side effects go away gradually during the recovery periods between treatments or after treatment stops.

Some anticancer drugs can affect a patient’s fertility. Women’s menstrual periods may become irregular or stop, and women may have symptoms of menopause, such as hot flashes and vaginal dryness. Men may stop producing sperm. Because these changes may be permanent, some men choose to have their sperm frozen and stored. Most children treated for leukemia appear to have normal fertility when they grow up. However, depending on the drugs and doses used and on the age of the patient, some boys and girls may not be able to have children when they mature.

Radiation Therapy
Patients receiving radiation therapy may become very tired. Resting is important, but doctors usually suggest that patients remain as active as they can.

When radiation is directed to the head, patients often lose their hair. Radiation can cause the scalp or the skin in the treated area to become red, dry, tender, and itchy. Patients will be shown how to keep the skin clean. They should not use any lotion or cream on the treated area without the doctor’s advice. Radiation therapy also may cause nausea, vomiting, and loss of appetite. These side effects are temporary, and doctors and nurses can often suggest ways to control them until the treatment is over.

However, some side effects may be lasting. Children (especially young ones) who receive radiation to the brain may develop problems with learning and coordination. For this reason, doctors use the lowest possible doses of radiation, and they give this treatment only to children who cannot be treated successfully with chemotherapy alone.

Also, radiation to the testicles is likely to affect both fertility and hormone production. Most boys who have this form of treatment are not able to have children later on. Some may need to take hormones.

Bone Marrow Transplantation
Patients who have a bone marrow transplant face an increased risk of infection, bleeding, and other side effects of the large doses of chemotherapy and radiation they receive. In addition, graft-versus-host disease (GVHD) may occur in patients who receive bone marrow from a donor. In GVHD, the donated marrow reacts against the patient’s tissues (most often the liver, the skin, and the digestive tract). GVHD can be mild or very severe. It can occur any time after the transplant (even years later). Drugs may be given to reduce the risk of GVHD and to treat the problem if it occurs.

Nutrition for Cancer Patients
Some cancer patients find it hard to eat well. They may lose their appetite. In addition, the common side effects of therapy, such as nausea, vomiting, or mouth sores, can make eating difficult. For some patients, foods taste different. Also, people may not feel like eating when they are uncomfortable or tired.

Eating well means getting enough calories and protein to help prevent weight loss and regain strength. Patients who eat well during cancer treatment often feel better and have more energy. In addition, they may be better able to handle the side effects of treatment.

Doctors, nurses, and dietitians can offer advice for healthy eating during cancer treatment. Patients and their families also may want to read the National Cancer Institute booklets Eating Hints for Cancer Patients and Young People With Cancer: A Handbook for Parents, which contain many useful suggestions.

Followup Care
Regular followup exams are very important after treatment for leukemia. The doctor will continue to check the patient closely to be sure that the cancer has not returned. Checkups usually include exams of the blood, bone marrow, and cerebrospinal fluid. From time to time, the doctor does a complete physical exam.

Cancer treatment may cause side effects many years later. For this reason, patients should continue to have regular checkups and should also report health changes or problems to their doctor as soon as they appear.

Support for Cancer Patients
Living with a serious disease is not easy. Cancer patients and those who care about them face many problems and challenges. Coping with these problems is less difficult when people have information and support. Several useful booklets are available from the Cancer Information Service. These include Taking Time: Support for People With Cancer and the People Who Care About Them and Young People With Cancer: A Handbook for Parents. (Other booklets are listed in the Other Booklets section.)

Cancer patients may worry about holding their job, caring for their family, or keeping up with other responsibilities. Parents of children with leukemia may worry about whether their children will be able to take part in normal school or social activities, and the children themselves may be upset about not being able to join in activities with their friends. Worries about tests, treatments, hospital stays, and medical bills also are common. Doctors, nurses, and other members of the health care team can answer questions about treatment, working, or other activities. Also, meeting with a social worker, counselor, or member of the clergy can be helpful to patients who want to talk about their feelings or discuss their concerns.

Friends and relatives can be very supportive. Many patients also find it helps to discuss their concerns with others who have cancer. Cancer patients often get together in support groups, where they can share what they have learned about coping with cancer and the effects of treatment. In addition to groups for adults with cancer, special support groups for children with cancer or their parents are available in many cities. It is important to keep in mind, however, that each patient is different. Treatments and ways of dealing with cancer that work for one person may not be right for another — even if they both have the same kind of cancer. It is always a good idea to discuss the advice of friends and family members with the doctor.

Often, a social worker at the hospital or clinic can suggest groups that can help with rehabilitation, emotional support, financial aid, transportation, or home care.

What the Future Holds
Researchers are finding better ways to treat leukemia, and the chances of recovery keep improving. Still, it is natural for patients and their families to be concerned about the future.

Sometimes people use rates of survival and other statistics to try to figure out whether a patient will be cured or how long the patient will live. It is important to remember, however, that statistics are averages based on large numbers of patients. They cannot be used to predict what will happen to a certain patient because no two patients are alike; treatments and responses vary greatly. The doctor who takes care of the patient is in the best position to discuss the chance of recovery (prognosis). Patients and their families should feel free to ask the doctor about the prognosis, but they should keep in mind that not even the doctor knows exactly what will happen. Doctors often talk about surviving cancer, or they may use the term remission, rather than cure. Even though many leukemia patients are cured, doctors use these terms because the disease can recur.

Possible Causes
At this time, we do not know what causes leukemia. Researchers are trying to solve this problem. Scientists know that leukemia occurs in males more often than in females and in white people more often than in black people. However, they cannot explain why one person gets leukemia and another does not.

By studying large numbers of people all over the world, researchers have found certain risk factors that increase a person’s risk of getting leukemia. For example, exposure to large amounts of high-energy radiation increases the risk of getting leukemia. Such radiation was produced by the atomic bomb explosions in Japan during World War II. In nuclear power plants, strict safety rules protect workers and the public from exposure to harmful amounts of radiation.

Some research suggests that exposure to electromagnetic fields is a possible risk factor for leukemia. (Electromagnetic fields are a type of low-energy radiation that comes from power lines and electric appliances.) However, more studies are needed to prove this link.

Certain genetic conditions can increase the risk for leukemia. One such condition is Down’s syndrome; children born with this syndrome are more likely to get leukemia than other children.

Workers exposed to certain chemicals over a long period of time are at higher risk for leukemia. Benzene is one of these chemicals. Also, some of the drugs used to treat other types of cancer may increase a person’s risk of getting leukemia. However, this risk is very small when compared with the benefits of chemotherapy.

Scientists have identified a virus that seems to increase the risk for one very uncommon type of leukemia. However, this virus has no known association with common forms of leukemia. Scientists throughout the world continue to study viruses and other possible risk factors for leukemia. By learning what causes this disease, researchers hope to better understand how to prevent and treat it.