Chemotherapy

Chemotherapy is the use of medication
(chemicals) to treat disease. More specifically,
chemotherapy typically refers to the destruction
of cancer cells. However, chemotherapy may also
include the use of antibiotics or other
medications to treat any illness or infection.
This article concentrates on chemotherapy for
cancer treatment. Cytotoxic medication prevents
cancer cells from dividing and growing. When
health care professionals talk about chemotherapy
today, they generally tend to refer more to
cytotoxic medication than others.
How did chemotherapy start ?
After a military operation in World War II some
sailors were accidentally exposed to mustard gas.
They were later found to have very low white
blood cell counts. White blood cells usually grow
very quickly - cancer cells also divide and grow
very quickly.
The doctors wondered whether the effect of
mustard gas - slowing down the rapid growth of
white blood cells - may have the same effect on
cancer cell growth.
Doctors tried testing patients with advanced
lymphomas by injecting a chemical in mustard
gas. Even though the effect was temporary, the
patients did experience a remarkable
improvement.
This led to research into other substances that
might slow down or stop the division and growth
of cancer cells. Over the decades several new
improved drugs were created.
There are more than 100 different types of
chemotherapy drugs today which can treat most
cancers.
Genetic testing is helping doctors target
chemotherapy more accurately. Testing for
genetic mutations can help identify breast cancer
patients who will not benefit from a specific type
of chemotherapy, scientists from the USA and
Norway reported.
By studying the patterns in which light bounces
off the surfaces of cells, researchers may be able
to assess chemotherapy's success in triggering
cancer cell death , according to a study led by
investigators in the Duke Comprehensive Cancer
Center and Duke's Pratt School of Engineering.
Chemotherapy is often used alongside other
treatments. Doctors and patients should take
physical exercise seriously, because of the
benefits for many cancer patients. Patients who
regularly exercise after chemotherapy treatment
have a much lower risk of cancer recurrence ,
compared to people who are physically inactive,
researchers from the University of Nebraska
reported at The Integrative Biology of Exercise VI
meeting in October 2012. They say their findings
may help investigators understand why exercise
may greatly reduce the risk of secondary cancer in
survivors. They added that physical activity can
also lower the chances of ever developing cancer
among those who have never had the disease.
Chemotherapy has five possible goals
Total remission - to cure the patient completely.
In some cases chemotherapy alone can get rid of
the cancer completely.
Combination therapy - chemotherapy can help
other therapies, such as radiotherapy or surgery
have more effective results.
Delay/Prevent recurrence - chemotherapy, when
used to prevent the return of a cancer, is most
often used after a tumor is removed surgically.
Scientists at the Charite School of Medicine,
Germany, found that the use of the drug
gemcitabine for chemotherapy significantly delays
the recurrence of cancer, compared to no
chemotherapy .
Slow down cancer progression - used mainly
when the cancer is in its advanced stages and a
cure is unlikely. Chemotherapy can slow down
the advancement of the cancer.
To relieve symptoms - also more frequently used
for patients with advanced cancer.
How does chemotherapy work ?
When our body cells are damaged or die we
produce new ones to replace them. This is done
in an orderly way, in a balanced way. Cancer cells
do not have that orderly capacity - their
reproduction (division and growth) is out of
control - more and more of them are produced
and they start to occupy more and more space,
until eventually they push out space occupied by
useful cells.
Chemotherapy (chemo) drugs interfere with a
cancer cell's ability to divide and reproduce.
Chemo drugs may be applied into the
bloodstream to attack cancer cells throughout the
body, or they can be delivered directly to specific
cancer sites.
Chemotherapy drugs work in various ways:
Impairing mitosis (prevent cell division) - these
are known as cytotoxic drugs.
Targeting cancer cell's food source, enzymes and
hormones they require in order to grow.
Stopping the growth of new blood vessels that
supply a tumor. In a study, researchers at the
Johns Hopkins University School of Medicine
discovered how a whole class of commonly used
chemotherapy drugs can destroy cancer by
blocking blood vessel growth .
Triggering suicide of cancer cells - cell suicide is
known medically as apoptosis .
Patients may receive monotherapy or
combination therapy:
Monotherapy - the patient is given just one drug.
Combination therapy - the patient receives more
than one drug.
Which type the patient receives will depend on the
kind of cancer the patient has, as well as some
other health considerations.
Chemotherapy may be given at different stages
Neo-adjuvant therapy - if the tumor is large the
surgeon may want to shrink it before surgery.
This may involve some pre-operative
chemotherapy and/or radiotherapy.
Chemoradiation therapy - the chemotherapy is
given in combination with radiotherapy. Patients
with localized Hodgkin's lymphoma where the
tumor is situated above the diaphragm should be
given chemotherapy combined with radiotherapy,
European scientists reported after carrying out a
clinical trial. Another study reported that the
solid tumor cells that survive chemoradiation
therapy often end up stronger than they were
before .
Adjuvant therapy - chemotherapy given after
surgery. The use of chemotherapy following
surgery reduces the risk of death from operable
pancreatic cancer by around 30% , a UK study
found.
Often age will determine whether chemotherapy
should be used at all for patients with certain
cancers. Researchers at The Mayo Clinic, USA,
found that the combination of chemotherapies
5FU and oxaliplatin compared to 5FU alone after
surgery for colon cancer decreases colon cancer
recurrence and promotes longer survival for
patients under 70 - but not for those who are
older.
How long is a course of chemotherapy ?
In the majority of cases for best results the
patient will need regular chemotherapy over a
specific period. A protocol plan is drawn up which
specifies when treatment sessions will occur and
for how long.
A course of chemotherapy may be just a one-day
treatment, or can last for a few weeks - it will
depend on the type and stage of the cancer (how
advanced it is). If the patient requires more than
one course of treatment there will be a rest period
for his/her body to recover. This could be a one-
day treatment followed by a week's rest period,
followed by another one-day treatment followed
by a three-week rest period, etc. This may be
repeated many times.
How many health care professionals are involved
in chemotherapy treatment ?
This will depend on working practices of your
hospital, or even the country you live in. In most
countries there will be a multi-disciplinary team
who treat the patient's cancer. These may
include:
A clinical oncologist - a doctor who specializes
in cancer but does not do surgery. He/she is
specialized in chemotherapy.
A cancer nurse - probably the first person the
patient will meet when coming in for
chemotherapy.
A hematologist - this is a doctor who is
specialized in the study of blood and bone
marrow.
A pathologist - this is a doctor who specializes
in the identification of diseases by examining
cells and tissues under a microscope.
A psychologist - he/she will help the patient deal
with the mental and emotional ordeal of
chemotherapy.
Blood tests before and during chemotherapy
treatment
Blood tests are needed to assess the health of
the patient as well as ensuring that he/she will
be able to cope with possible side-effects. For
example, blood tests can detect liver problems,
which could mean that chemotherapy is
unsuitable for the patient unless the liver
recovers. Chemotherapy chemicals are
metabolized (broken down) in the liver which
could be harmed if it is not working properly.
Before chemotherapy it is important to test the
patient's blood count because the treatment will
reduce the number of red and white blood cells,
as well as platelets. If a blood test reveals a low
blood count the doctors may decide to delay
treatment.
Researchers at the Paul Papin Cancer Center in
Angers, France, reported that measuring drug
levels in patients' blood and adjusting them for
optimal dosing can substantially reduce severe
toxicity and improve efficacy in colorectal cancer.
Regular blood tests will continue during the
treatment period so that the medical team can
keep an eye on blood count and the state of the
patient's liver. As you may read under side-
effects further down this page, there is a risk that
chemotherapy may lower white, red, and platelet
blood level counts.
Monitoring the patient's blood can also provide
doctors with important data on how well the
chemotherapy is working.
Two ways of giving chemotherapy
Depending on the type of cancer, chemotherapy
may be administered orally or intravenously
(directly into the vein).
Oral chemotherapy (swallowing tablets)
These will be in the form of tablets. If the
patient's health allows it he/she will be able to
take them at home. However, regular hospital
visits will still be needed to check on the
patient's health and response to treatment.
It is vital that the tablets be taken exactly when
specified. If the patient forgets to take one at a
specific time he/she should call the medical team
immediately.
Intravenous chemotherapy (straight into the
vein)
Intravenous chemotherapy may be given as:
An injection straight into a vein.
Through a drip (intravenous infusion).
Through a drip or pump.
Through a pump that the patient wears for
several weeks or months. This is called
continuous infusion, protracted venous
infusion, or ambulant infusion (meaning the
patient can walk about while receiving the
medication).
There are different ways of getting the
medication into the patient. These include:
A cannula - a thin tube is inserted through
the skin into the vein - usually it enters the
body via the back of the hand or the lower
arm.
A drip (intravenous infusion) - in order to
dilute the medication it may be injected into
a bag. The solution in the bag will pass
through a tube into the patients arm and
into a vein (intravenous infusion). A cannula
will be used. The solution will enter the vein
slowly.
Chemotherapy through a drip generally is
pushed through with a pump. The pump
does not hurry the process up, rather it
makes sure the solution enters the vein at a
constant rate over a specific period - the
slower the rate, the longer the whole thing
will take.
A central line - this is a long, flexible,
plastic line (thin tube) which ends up in a
central blood vessel in the chest, close to
the heart. The central line usually enters the
body through the center of the chest and
goes up under the skin into a large vein by
the collarbone (clavicle). The only visible
part is the length of line that hangs out of
the small entry hole in the chest.
A peripherally inserted central catheter
(PICC) line - a long, thin, flexible tube that
is inserted into a peripheral vein, usually in
the upper arm and makes its way into a
large vein in the chest near the heart. It is
similar to a central line but has a different
point of entry.
A portacath (implantable port) - a thin, soft,
flexible plastic tube goes into a vein. It has
a port (opening) just under the skin of the
chest or arm. The port has a thin rubber
disc which special needles can pass
medicines into, or take blood from.
Pregnancy and contraception
Many chemotherapy drugs may cause birth
defects. It is important that a woman undergoing
chemotherapy avoids becoming pregnant. As
most chemotherapy medications interfere with
oral contraceptives it is important to use a barrier
method of contraception , such as condoms,
during the whole chemotherapy treatment period
and for a year after treatment is completed. If you
are pregnant you need to tell the medical team
straight away beforehand. If you become
pregnant during treatment tell the medical team
straight away.
What are the side effects of chemotherapy?
Most people immediately link chemotherapy with
uncomfortable side effects. However, side-effect
management has improved considerably over the
last twenty years. Many side effects that were
once inevitable can be either prevented or well
controlled today.
There is no reliable way to predict how patients
may react to chemotherapy. Some experience
very mild side-effect, others will have none at all,
while some people will report various symptoms.
Depending on the type of cancer and treatment,
chemotherapy may have a bigger impact on the
patient's work status than radiotherapy. Women
with breast cancer who receive chemotherapy
appear more likely than those treated with
radiation therapy to experience a major change in
work status, according to researchers at the
Dana-Farber Cancer Institute.
Below is a list of the most commonly reported
side effects:
Nausea and vomiting
Over half of all patients receiving chemotherapy
will experience nausea and vomiting. Doctors will
usually prescribe anti-emetics for this. These
need to be taken even when symptoms have gone
as they will prevent them from coming back. If
the anti-emetics do not work the patient should
contact his/her doctor who may switch to
another anti-emetic.
Ginger - scientists at the Rochester University
Medical Center found that taking ginger
supplements with standard anti-vomiting drugs
beforehand can reduce the nausea that often
accompanies chemotherapy treatment by 40% .
Alopecia (Hair loss)
Some chemotherapy medications cause hair loss
while others don't. If hair does start to fall out
this will usually happen a few weeks after
treatment starts. On some occasions the hair will
just become thinner and more brittle (without
falling out). Hair loss can occur in any part of the
body.
Although hair loss has no physical health
consequences, it may cause distress and
embarrassment for some people. The
psychological impact tends to be greater among
women than men. If you experience hair loss and
find it is causing distress and embarrassment,
there are several steps you can take:
Tell your doctor, who may refer you to a
counselor who can provide effective help and
support.
Many people find that if they purchase a wig their
quality of life improves significantly.
If there is a cancer support group in your area,
go to their meetings. Meeting people who share
similar experiences to yourself may help give you
a boost, as well as providing you with some
useful tips, and possibly an opportunity to make
new friends.
Cold cap - this looks a bit like a bicycle helmet
and keeps the scalp cool while the chemotherapy
dose is being administered. If the scalp can be
kept cool less chemotherapy medication reaches
the scalp, thus preventing the occurrence or
reducing the severity of hair loss. Some people
cannot wear a cold cap - leukemia (blood
cancer) patients need the medication to reach
their scalp.
The hair loss is NOT permanent - it will grow
back soon after treatment if finished.
Fatigue
Most patients receiving chemotherapy will
experience some degree of fatigue . This may be a
general feeling which exists most of the day, or
may only appear after certain activities. Doctors
say patients need to make sure they get plenty of
rest and not to perform tasks which are
overtiring.
While light exercise has been shown to help, it is
important to remember to keep the activities
'light'.
If the tiredness becomes severe it is important to
tell the doctor, as this could be caused by a
significant drop in red blood cells ( anemia ).
Hearing impairment (deafness, ototoxicity)
Scientists from Oregon Health & Science
University reported that deafness as a side effect
of chemotherapy has long been underreported by
the medical community, because a well-known
classification system doctors use for reporting
toxicities in patients does not consider high-
frequency hearing loss , allowing the magnitude of
ototoxicity (hearing damage) in children treated
with platinum agents to be miscalculated.
Children with cancer who suffer hearing loss due
to the toxic effects of chemotherapy might one
day be able to get their hearing back through
pharmacological and gene therapy, said
researchers from St. Jude Children's Research
Hospital after carrying out a study on mice.
Neutropenia (low white blood cells) -
Susceptibility to infections
When receiving chemotherapy the immune system
will be weakened because the white blood cell
count will go down. White blood cells form part of
our immune system - they fight infection.
Consequently, patients become more susceptible
to infections.
Some patients will be prescribed antibiotics which
may reduce their risk of developing infections. The
following precautions will help reduce the risk of
infections:
Personal hygiene - the cleaner you are, the fewer
bacteria there will be around which can infect
you. Regularly wash your hands with warm water
and soap, have a bath/shower at least once a
day, change your clothes and bathroom towels
and flannels daily. Change your bed linen
regularly.
Preparing food - make sure your food is free of
food borne pathogens (organisms, such as
bacteria that can make you ill). If you handle raw
meat make sure you wash your hands before
touching plates and cutlery or work surfaces.
Thoroughly cook animal sourced proteins before
eating them. Wash your dishes thoroughly and
always use a clean plate and cutlery - keep the
kitchen clean.
Infected people - stay away from people who are
ill. This may include those who just have a
temperature.
Skin wounds - bacteria find it hard to get in
through your skin, unless there is a cut. If you
graze or cut your skin, clean the area well with
warm water, dry it, and cover it with a sterile
dressing.
Patients receiving chemotherapy who develop an
infection need immediate treatment. This may
mean being hospitalized and receiving antibiotics
via an intravenous drip.
Thrombocytopenia (low blood platelet count) -
Blood clotting problems
Chemotherapy may lower the patient's blood
platelet count. A platelet is a type of blood cell
that helps the blood to clot (coagulate).
Coagulation is essential, otherwise bleeding does
not stop. Lower blood platelet counts linked to
chemotherapy is a risk, but less so than lower red
or white blood cell counts. If you are affected you
will bruise more easily, you will be more likely to
have nosebleeds and bleeding gums, and if you
cut yourself it may be harder to stop the
bleeding.
Patient's whose blood platelet counts fall too low
will need a blood transfusion.
Below are some steps you may wish to take to
reduce your risk of bleeding:
Shave with an electric razor (or don't shave)
Avoid hard toothbrushes
Use kitchen utensils and gardening equipment
carefully
If you are gardening, wear gloves.
Anemia (low red blood-cell count)
As well as lowering you white blood cell count,
chemotherapy will also lower your red blood cell
count. Tissues and organs inside your body get
their oxygen from the red blood cells. If your red
blood cell count goes down too many parts of
your body will not get enough oxygen and you will
develop anemia.
People with anemia feel very tired. A patient on
chemotherapy who has anemia will feel extra tired
- much more tired than straightforward fatigue
caused by the treatment. Dyspnea (shortness of
breath) is also another symptom of anemia, as
are palpitations (when the heart beat is irregular).
Anemia linked to chemotherapy requires
immediate treatment. A blood transfusion will
bring the red blood cell count back up
immediately. Erythropoietin (EPO) is a drug that
makes the body produce more red blood cells.
The following foods are rich in iron, which helps
red blood cells carry more oxygen. Dark green
leafy vegetables, beans, meat, nuts, prunes,
raisins, and apricots.
Scientists from The Medical University of Vienna,
Austria found that patients with breast cancer
who developed anemia during chemotherapy had
nearly three times the risk of local recurrence as
those who did not .
Mucositis (inflammation of the mucous
membrane)
Chemotherapy attacks rapidly dividing cells, such
as blood cells, bone marrow cells, and cells of the
mucous membranes that line the digestive system
- this includes the mouth, esophagus, stomach,
intestines, and the rectum to the anus.
Chemotherapy may damage and even destroy
some of those mucous membrane cells.
Oral Mucositis (in the mouth) - patients more
commonly experience symptoms in their mouth.
If symptoms do appear, they will usually do so
about 7 to 10 days after treatment starts. The
inside of the mouth may feel like sunburn; some
people say it feels as if the area had been
scalded. Ulcers often appear on the lining of the
mouth, the tongue, and sometimes around the
lips. The severity of symptoms is closely linked to
the strength of the chemotherapy dose.
Some may find it painful when they eat, drink, or
even talk. If the ulcers bleed there is a risk of
infection.
Caphosol is often prescribed for mucositis.
A clinical trial showed that out of 100 cancer
patients that were treated with DAVANAT® and
chemotherapy that included 5-FU, none developed
mucositis.
As better drugs are appearing, mucositis is
becoming less common. Symptoms clear up a few
weeks after treatment is completed.
Loss of appetite
Loss of appetite is a common side effect of
chemotherapy. It is possible that the
chemotherapy, or the cancer itself, affects the
body's metabolism. If the loss of appetite is just
due to the chemotherapy it will come back when
the treatment is finished - although this may
sometimes take a few weeks.
The severity of appetite and consequent weight
loss depends on the type of cancer and
chemotherapy treatment.
Although this is sometimes easier said than done,
it is important to keep trying to eat well and take
in plenty of fluids. Many patients find that smaller
and more frequent meals are easier to get down
than the typical three meal-a-day regime. Also,
drinking liquids through a straw may result in a
better fluid intake.
Patients who become seriously affected by lack of
food and liquid intake may need to be
hospitalized and fed through a nasogastric tube.
The tube goes into the patient's nose and down
to his/her stomach.
Nails and skin
Chemotherapy can sometimes cause dry and sore
skin. Nails may also become flaky and brittle.
The skin may become more sensitive to sunlight.
It is important to protect yourself from too much
sunlight exposure. This includes staying out of
the sun during peak times of the day, using sun
blocks, and wearing clothes that provide
maximum protection. Surprisingly, scientists at
Michigan University, USA, reported that the
chemotherapy drug fluorouracil appeared to
reduce the appearance of sun-damaged and aging
skin as well as the number of potentially pre-
cancerous skin patches.
Cognitive problems
About one fifth of patients undergoing
chemotherapy report some kind of cognitive
problem, including attention, thinking and
memory. This can sometimes have an impact on
daily tasks. Patients who do experience these
symptoms should talk to their doctor, and social
worker.
Symptoms may include:
Shorter attention span; concentration, focus and
attention problems
Memory problems; especially the short-term
memory
Comprehension and understand problems
Judgment and reasoning problems
Organizational skills may be affected
Multitasking problems (performing/thinking about
several things at the same time)
Mood swings.
Experts are unsure how much is due to the
chemotherapy, and how much is due to fatigue,
stress and anxiety that comes with having cancer.
Libido (sex drive) and fertility
For a significant proportion of patients,
chemotherapy may result in a lower sex drive
(less interest in sex). This is temporary and
usually returns after treatment is completed.
Depending on the type of medication
administered, chemotherapy may also damage
men's sperm. Some women may become infertile .
In most cases - though not all - fertility returns
after treatment is over.
Men who wish to father children and women who
plan to become pregnant one day should discuss
possible options with their doctors before starting
treatment. It is possible to freeze sperm and
embryos.
Bowel movement problems (diarrhea or
constipation)
Sometimes when damaged cells in the intestinal
tract are rapidly expelled from the body there is a
risk of diarrhea . Constipation is also a possible
risk for chemotherapy patients. You should talk to
your doctor if you experience any unpleasant
change in your bowel movements. Symptoms, if
they do occur, will do so a few days after
chemotherapy begins.
Depression
The risk of developing depression is already
higher for patients with cancer. It is normal to
feel distressed, anxious, sad and stressed -
especially if you are concerned about what the
future holds and whether treatment is going to be
effective.
It is important that you talk to a member of the
medical team if you feel it is all getting to be too
much, or if you no longer get pleasure out of the
things that you used to like. Joining a support
group and talking to people who are going
through the same as you and understand how
you feel has helped many people with cancer.
Protecting the gut from chemotherapy in cases of
metastatic cancer
When cancer has spread beyond the primary
tumor to other parts of the body, i.e. when it has
metastasized, treatments tend to involve intensive
chemoradiotherapy. These high doses of
raditation therapy and chemotherapy damage
good tissue and often push the patient to an early
death.
Researchers from the University of Michigan
School of Dentistry reported in the journal Nature
that they found a way to preserve the health of
the gut in laboratory mice that had been given
very high doses of chemoradiotherapy.
Team leader, Jian-Guo Geng, said "All tumors
from different tissues and organs can be killed by
high doses of chemotherapy and radiation, but
the current challenge for treating the later-staged
metastasized cancer is that you actually kill the
patient before you kill the tumor."
Healthy digestive tract improves survival - the
scientists found that if the gut of mice with
metastatic cancer stayed healthy after intensive
chemoradiotherapy, their chances of survival
increased exponentially.
There are stem cells in the gut of the laboratory
mice that help preserve tissue after undergoing
lethal doses of chemoradiotherapy. Geng and
colleagues found a way of getting the gut stem
cells to launch a massive healing campaign.
Gene Print Predicts Who Will Survive
Chemotherapy
An 8-gene "print" or "signature" can predict how
long people remain cancer-free, without any
relapse after undergoing chemotherapy,
researchers from Academia Sinica and the
National Taiwan University College of Medicine
explained in the journal BMC Medicine .
Prof Ker-Chau Li and team located genes that are
involved in cellular invasion - something several
cancer cells do. They gathered and examined data
from the National Cancer Institute's 60 human
cancer cell line panel.
Prof. Li said "Our study found eight genes which
were involved in invasion, and the relative
activation of these genes correlated to
chemotherapy outcome, including the receptor for
growth factor EGF. We also found that some
invasion genes had unique patterns of expression
that reflect the differential cell responses to each
of the chemotherapy agents - five drugs
(paclitaxel, docetaxel, erlotinib, everolimus and
dasatinib) had the greatest effect."
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