lukemia, luekemia
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 cancer is 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 Symptoms
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.
Diagnosis of Leukemia
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.
Leukemia Treatment
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 Leukemia 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?
Leukemia 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.
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 Leukemia 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.
Leukemia Treatment with Chemotherapy
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.
Leukemia Treatment with 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.
Leukemia Treatment with Bone Marrow Transplants
Patients who have bone marrow transplants 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 bone marrow transplant (even
years later). Drugs may be given to reduce the risk of GVHD and to treat
the problem if it occurs.
Nutrition for Leukemia 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.
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 Leukemia 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.
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 of Leukemia
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.
Keeping on Top of Your Condition
Keeping in tune with your disease or condition not only makes treatment less intimidating but also increases its chance of success, and has been shown to lower a patients risk of complications. As well, as an informed patient, you are better able to discuss your condition and treatment options with your physician.
A new service available to patients provides a convenient means of staying informed, and ensures that the information is both reliable and accurate. If you wish to find out more about HealthNewsflash's innovative service, take the tour.
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