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Bioinformatics
Research Laboratory
IBI Biosolutions Pvt. Ltd.
Panchkula - 134109, INDIA. |
| An
Approach to Define Molecular Biology of Leukemia Virus |
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| Frequently
Asked Questions About Leukemia |
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Q.
What is leukemia?
A. 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 with 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.
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.
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Q.
What are the symptoms of leukemia?
A. 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
- 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
- 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, 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.
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Q.
How is leukemia diagnosed?
A. 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 in the lymph nodes under 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 a 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 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.
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Q.
What is the treatment for leukemia?
A. Treatment for leukemia is complex.
It varies with the type of leukemia, and it is not the same
for all patients. 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. The doctor plans the treatment
to fit each patient's needs. Whenever possible, patients should
be treated at a medical center that has doctors who have experience
in treating leukemia.
Acute leukemia needs to be treated right away. The goal of
treatment is to bring about 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.
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.
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?
- If
I have pain, how will you help me?
- Will
I have to change my normal activities?
- How
long will the treatment last?
- What
is the treatment likely to cost? How can I find out what
my insurance will cover?
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Q.
What about a second opinion?
A. Sometimes it is helpful to have a
second opinion about the diagnosis and treatment plan. (Many
insurance companies provide coverage for a second opinion.)
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Q.
Can you tell me something about the methods of treatment?
A. 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
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?
Antibody
therapy is a leukemia treatment using molecularly targeted
drugs, called monoclonal antibodies, that can directly kill
specific tumor cells or stimulate the immune system to kill
cancer cells. It is generally less toxic than chemotherapy
and radiation.
Blood
and 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 health 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 if the treatment is working?
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.
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 trials involve various forms of biological therapy. Interleukins
and colony stimulating factors are forms of biological therapy
being studied to treat leukemia. Doctors are also studying
ways to use monoclonal antibodies in the treatment of leukemia.
Often biological therapy is combined with chemotherapy or
bone marrow transplantation.
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Q.
What about problems that can arise as a result of treatment?
A. 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 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.
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Q.
What are the side effects of treatment?
A. It is hard to limit the effects of
therapy so that only leukemia cells are destroyed. Treatment
also damages healthy cells and tissues; this 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.
Chemotherapy:
The side effects of chemotherapy depend mainly on the drugs
the patient receives. 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. Some healthy cells
may also 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. They 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
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 very 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 skin in the treated
area to become red, dry, tender and itchy. Patients will be
shown how to keep their 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. 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:
Some cancer patients find it hard to eat well. They may lose
their appetite. 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.
Follow-Up Care:
Regular follow-up 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. Check-ups
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
check-ups and should also report health changes or problems
to their doctor as soon as they appear.
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Q.
What are some of the causes for leukemia?
A. 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:
- Exposure
to large amounts of high-energy radiation
- Exposure
to electromagnetic fields (more studies needed to link
this)
- Certain
genetic conditions
- Workplace
chemicals
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©
2007 IBI Biosolutions Pvt. Ltd.
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