Chemotherapy
Chemotherapy is the use of special anti-cancer
(cytotoxic) drugs to destroy cancer cells.
Adjuvant
therapy
Doctors may prescribe `adjuvant therapy' after
surgery for cancer of the colon or rectum. Adjuvant therapy is
given when all the tumour has been removed but the appearance
of the tumour under the microscope suggests that there is a
strong chance that the cancer might recur. This is more likely
if the lymph nodes have been affected.
The reasons why cancer
may spread to other parts of the body are not known. The
original cancer may have released cells into the bloodstream
or the lymphatic system, and these can sometimes set up tiny
cancers (called metastases or 'secondaries') in
other parts of the body. These may be so minute that they
remain undetected for several years.
Adjuvant
chemotherapy
A chemotherapy
drug called 5-fluorouracil
(5FU) is usually prescribed as adjuvant therapy for cancers of
the colon and rectum.
5FU is usually given in
combination with a vitamin called folinic acid. It may
sometimes be given with a drug called levamisole. It is not
yet known how levamisole works, but it is thought that it may
have some effect on the immune system.
There are several
different ways of giving this treatment. Your doctor will
discuss your particular type of treatment with you.
Newer adjuvant
treatments
There is some evidence to show that an
antibody treatment (which is not chemotherapy)
called 17-1A (more commonly known as Panorex) may also be
helpful as adjuvant therapy in preventing the disease coming
back.
This treatment is given
as a drip into a vein in the arm, lasting a few hours. Usually
it is done as an out-patient.
This treatment is still
experimental and is not yet licensed.
Chemotherapy for
secondary cancer or cancer that is advanced (has spread beyond
the bowel) at diagnosis
Many people have no
further problems after their original treatment for cancer of
the large bowel but, unfortunately, in some people the cancer
does come back or spread to other parts of the body. This is
called secondary (or metastatic) cancer of the large
bowel. Sometimes, too, when the cancer is first diagnosed it
may already have spread beyond the bowel.
The most important fact
to remember is that secondary cancer of the large bowel can
often be treated. A number of factors will be considered by
your doctor before deciding on which treatment you will be
given. These include: which part of your body is affected by
secondary cancer cells; what kind of adjuvant treatment you
had in the past; and your general health.
As with adjuvant chemotherapy,
a chemotherapy drug called 5-fluorouracil
(5FU) may be used. It works more effectively if it is given
with a vitamin called folinic acid. 5FU can be given either as
an injection directly into a vein in the arm or through a
continuous intravenous infusion. When the 5FU is given as a
continuous infusion, it is necessary to put in a `central
line', such as a Hickman line or Portacath. This line is a
length of narrow flexible plastic tubing which is inserted
into a main vein and then comes out onto the chest. It is left
in place for the length of your treatment. This makes it
easier for the doctors to give you the drugs and saves you the
pain and discomfort of repeated injections. You will be given
either a local or a general anaesthetic before the line is
inserted.
This chemotherapy
treatment may continue for months at a time as the side
effects are usually very mild.
Research is continuing to
try to determine the most effective way of giving 5FU.
Chemotherapy can be given
in several ways. It can be given as a course of treatment,
usually lasting several days. You will need to stay in
hospital for this treatment. This is followed by a rest period
of a few weeks, which allows your body to recover from any
side effects of the treatment. The number of courses you have
will depend on the type of cancer you have and how well it is
responding to the drugs.
Chemotherapy can also be
given as a weekly injection in the out-patient
department.
Side
effects
While the drugs are acting on the cancer cells
in your body they may also reduce temporarily the number of
normal cells in your blood. When these cells are reduced you
are more likely to get an infection and you may tire easily.
During chemotherapy
your blood will be tested regularly and, if necessary, you
will be given a blood transfusion or antibiotics to treat the
infection.
Other side effects may
include nausea and diarrhoea. Hair
loss is another side effect of chemotherapy but this is
uncommon with the drugs that are used for cancer of the bowel.
Some drugs also make your mouth sore and cause small mouth
ulcers. Regular mouthwashes are important and the nurse will
show you how to do these properly. If you don't feel like
eating you can replace your meals with nutritious drinks.
There are also medicines (anti-emetics) available from your
doctor which reduce the feeling of sickness and often stop you
feeling sick altogether.
Although they may be hard
to bear at the time, these side effects do disappear once your
treatment is over. If you lose your hair it will grow back
surprisingly quickly. Many people wear wigs, hats or scarves
until this happens. Most patients are entitled to a free wig
from the National Health Service and your doctor or the nurse
looking after you will be able to arrange this for you.
CancerBACUP has a booklet called Coping
with hair loss which we would be happy to send
you.
Your doctor will tell you
what problems, if any, to expect from your treatment. Tell
your doctor if you have any side effects, as most can be eased
with medicine.
Chemotherapy affects
people in different ways. Many are able to lead a normal life
during their treatment while others find that they become very
tired and have to take things more slowly. Just do as much as
you feel like and try not to overdo it.
New chemotherapy
drugs
Irinotecan: This drug has been shown to
cause shrinkage of the cancer in a proportion of people whose
cancers are resistant to 5-fluorouracil (5FU) and folinic
acid.
Research is going on to
determine the exact role of irinotecan in treating cancer of
the colon.
Tomudex:
This is a new drug for treating cancer of the colon and rectum
and is being used in some patients. It is used when 5FU and
folinic acid are either not tolerated or inappropriate. It is
given as a drip over 15 minutes every 3 weeks and is usually
well tolerated.
CancerBACUP's booklet Understanding
chemotherapy discusses the treatment and its side
effects in more detail. We would be pleased to send you a
copy. Factsheets
about individual drugs and their particular side effects are
also available.
