Of all the medical conditions, cancer is probably the
most dreaded and feared. But early diagnosis and
ever-improving modern treatments can often lead to a
One in three of us in the UK will
suffer from cancer at some time in our life, and one in five
of us will die from it. The most common cancers are lung,
breast, bowel, ovary, kidney and melanoma -- the most
dangerous form of skin cancer.
The good news is that
almost a third of the people who develop cancer will be
cured. And many more will live for several years with the
disease, without any problems directly linked to it.
HOW CANCER DEVELOPS
Our bodies are made up of a variety of different tissues.
Each is made up of millions of cells, all arranged in an
orderly manner. The appearance and shape of cells from
different organs and tissues vary. For example, liver cells
are completely different to skin cells.
lives, cells are constantly lost and replaced by a process
of division. Normally this process is under strict control,
so that exactly the right number are produced to replace
those that are lost. If an injury occurs, the rate of cell
production speeds up until it has healed, then slows down
OUT OF CONTROL
Malignant cancer cells divide and grow uncontrollably and
will continue to do so indefinitely unless some form of
treatment is given. Eventually, they become so numerous that
they are visible as a tumour or growth.
develop from the body's own normal cells in a series of
stages that takes place over many years. The first step is a
damaged gene in an individual cell.
The faulty gene may be
inherited or it may be triggered by factors such as smoking,
over-exposure to the sun, or certain types of bacterial or
But, once it has developed, it switches
off another gene which tells the cell when to stop dividing.
Abnormal cells are produced all the time, but are destroyed
by the body's defence system. When cancer occurs, for some
unknown reason, the system breaks down and an abnormal cell
LACK OF RESPONSE
The cell becomes progressively more abnormal and responds
less and less to the body's normal control mechanisms.
Eventually, there are enough cancerous cells to form a
tumour. Cells from the edge of the tumour then invade and
damage the surrounding tissues.
Though cancer usually develops unseen, the cells can
often be recognized before they become cancerous. For
example, a cervical smear test is designed to pick up
abnormal cells in the cervix at a pre-cancerous stage when
they can be easily treated.
most of us, the word 'tumour' automatically signifies
cancer. But, in fact, most tumours are found to be benign,
or harmless. Unlike malignant tumour cells, benign tumours
go on dividing, and may even push aside normal tissue, but
they do not invade it. they are also unlikely to spread.
It's the ability of cancer cells to spread, or
metastasize, that makes the disease so serious. Cancers
which metastasize early on are called aggressive tumours,
while others don't start to spread until a later stage.
Tumours are often graded depending on how aggressive they
The cells spread via the blood and they lymph --
fluid produced by the lymphatic system, which is part of the
immune system. At first, they pass into blood vessels in the
primary, or original, tumour. They may also pass into the
lymphatic system of surrounding tissues, from where they
drain back into the bloodstream. As the blood travels round
the body, some of the cells become stuck at the end of fine
blood vessels called capillaries in various organs
In a second stage of metastatis, the cancer
cells pass through the walls of the blood capillaries and
enter a nearby organ, such as the lungs, liver, bone or
brain. This organ is often far away from the original tumour.
Most of these cells die but some may survive to form
secondary tumours, which may also begin to metastasize.
WHAT CAUSES CANCER ?
Cancer is not just one disease. There are hundreds of
different types, but they all occur when cells multiply in
an uncontrolled way. Cancer has many different causes. The
biggest known risk factor is smoking, which causes over a
third of cancers and is responsible for a similar number of
Other factors can also play a part:
over-exposure to sunlight, which is linked to skin cancer;
high levels of radiation, which is associated with many
different types of cancer; certain infections, such as
hepatitis B which is linked to liver cancer, or infection
with HPV, the human wart virus which is linked to cervical
cancer; heavy alcohol consumption, which is linked to an
increased risk of cancer of the oesophagus, or gullet, and
also to a higher risk of breast cancer in women.
THE AGE CONNECTION
However, cancer is mainly a disease of old age. Though the
overall risk of death from cancer has actually gone up by
six per cent over the past 30 years, this is largely
because, thanks to modern medicine, better diet, sanitation
and hygiene, we are living long enough to reach an age when
we are at a high risk of cancer.
This risk varies and
depends on certain factors such as age, inherited
characteristics such as a fair skin, which increases the
risk of skin cancer, and inherited faulty genes, which will
increase the background risk of certain types of cancer.
For most of us, a diagnosis of cancer is devastating news,
but it is no longer an inevitable death sentence. There has
been a vast improvement in diagnosis and treatment in recent
years. Far fewer children now die of cancer than they did 20
years ago; there has been a significant decrease in stomach
and bowel cancer in adults, and lung cancer among men has
also gone down.
the same time, improved treatments have led to people with
other sorts of cancer surviving longer. For example, the
discovery of hormonal or cell-killing drugs, plus a new
awareness of the best time to perform surgery, has led to
more women living longer with breast cancer.
In the race
for a cancer cure, early diagnosis is vital - a small cancer
tumour is usually easier to treat than a well-developed one.
The first step in the diagnostic process is for you to be
alert to any suspicious symptoms, particularly bleeding, and
report them to your doctor as soon as possible. Of course,
these symptoms will probably turn out not to be cancer, but
it's better to be safe than sorry.
should never ignore suspicious symptoms such as :
* Bleeding from the anus, which can be a sign of bowel
from the vagina, either between periods or after the
menopause, can be a symptom of both cervical or uterine
cancer, especially in older women.
* Blood in the urine could be a clue to kidney or bowel
* Blood in
vomit should never be ignored, unless you have had a recent
nosebleed, as it can be a sign of stomach cancer.
* A persistent cough or hoarseness that isn't associated
with a cold or chest infection and goes on for longer than
two weeks can be a sign of cancer of the larynx or cancer of
change in bowel habits, for example going to the toilet more
or less frequently than usual, having alternate constipation
or diarrhoea, dark streaks in the stools or having black,
tarry stools, are signs of bleeding in the intestine.
* See the doctor, too, if you are losing weight without
dieting - the loss could be around 22kg (10lbs) over 10
weeks or less - especially if this is combined with
abdominal pain or a change in bowel habits.
the doctor suspects you may have cancer, he will refer you
to your local hospital for tests and diagnosis. Initial
tests may involve investigations such as X-rays and
ultrasound, which can reveal the presence of a lump.
part of the suspicious tissue will then be examined under
the microscope. This can be done either by biopsy - snipping
off a small piece of the tissue for examination - or by
cytology, which is studying cells from body fluids such as
sputum or cervical mucus for cancer cells.
The doctor will
then perform a thorough clinical examination, taking
particular care to check the lymph nodes adjacent to the
tumour to see whether the cancer has spread. Simple blood
tests are then run to check liver and bone function and a
chest X-ray looks for evidence of spread to these sites.
If the doctor suspects cancer has spread elsewhere in the
body, this area may also be scanned.
HOW SCANS WORK
scanning technique used is usually isotope scanning, where a
small amount of a radioactive substance is injected into the
body and the blood carries it to the suspected organ or area
of tissue. Here, it is scanned using a special instrument
which detects radiation. Cancerous cells are clearly visible
because they take up a different amount of radioactivity
than healthy tissue. Once the doctor has detailed knowledge
of the type of cancer, its stage of development and its
likely progress, he can then plan a treatment regime with
The aim of cancer treatment is to kill or
remove every cancer cell from the patient. There are several
different forms of treatment, which may be used alone or may
be combined, depending on the nature of the cancer.
REMOVING THE TUMOUR
Surgery is most often used to treat cancer of the skin,
stomach, bowel, uterus, breast and testicle. It may also be
used to cut out cancers in the face and neck, including the
thyroid gland and larynx, or voice box, as well as cancers
of the ovary and the prostate gland.
As it is vital to remove all the cancerous tissue, the
surgeon will cut out the tumour together with some
surrounding normal tissue. Since cancer usually spreads
first to lymph glands in the area near the tumour, the
surgeon may need to remove these too.
Where possible, the surgeon will also reconstruct the area
in which the cancerous tissue has been surgically removed.
For example, if you have had a mastectomy, or breast
removal, there are various techniques for giving you a new
breast. These include using muscle from other parts of the
body, such as the shoulder, and inserting a breast implant.
In many cases, surgery alone is all that is required.
However, additional forms of treatment may be given before
or after surgery to make it easier and more effective.
Doctors call this way of giving treatment adjuvant therapy.
High energy rays are used to damage the genetic material of
cancer cells so they are unable to divide. These might be
X-rays, or beta or gamma rays from a radioactive source. The
rays are beamed carefully at the area to be treated. Cancer
cells are more sensitive to radiotherapy than normal cells,
and so are killed at a greater rate.
Inevitably, radiotherapy also damages normal cells close to
the tumour. But, thanks to the body's ability to repair
itself, quite large doses of radiation can usually safely be
given, provided the treatment is given slowly. Treatment
only lasts a few minutes, is painless and is usually given
daily on an out-patient basis for five to six weeks.
Radiotherapy treatment may also be given externally, using
special X-ray machines which direct the rays to the body.
In some cases radioactive implants, such as special wires,
are inserted into the cancer, allowing large doses of
radioactivity to be delivered to the tumour itself with only
a small amount directed to the surrounding normal tissue. In
cancer of the thyroid gland, a radioactive drink of iodine
is sometimes used to destroy cancerous cells painlessly.
Some people experience few side-effects from radiotherapy
apart from tiredness. However, radiotherapy can make you
feel unwell, particularly if you have been feeling ill
beforehand as a result of the cancer.
Other side-effects may include nausea, vomiting, headaches,
diarrhoea and, where radiation is aimed at the stomach or
head, a sore mouth. Hair loss may also occur if the head is
treated but hair usually regrows within six months.
Radiotherapy may also be used to relieve symptoms of cancer,
particularly pain, in cases where a cure is not possible.
Chemotherapy involves treating cancer with cytotoxic, or
cell-poisoning, drugs. These destroy cancer cells by
combining with and damaging the genetic material of the
cells so that they cannot divide. Unfortunately, these drugs
poison all rapidly dividing cells, causing side-effects such
as hair loss, nausea and a lowered blood count.
Damage to normal cells can be minimized by giving large
doses of drugs all at once, then leaving a gap of a few
weeks before the next treatment to allow normal cells to
recover. Chemotherapy may be given intravenously, injected
into a muscle, or by mouth.
Where there is a risk of relapse after surgery and/or
radiotherapy, chemotherapy is given even when there is no
sign of cancer present. This treatment technique is known as
Some cancers are affected by hormonal levels in the body.
Hormone therapy involves either blocking, reducing or
increasing hormone levels to act on the cancer. The main
types of cancer treated in this way include certain types of
breast cancer as well as prostate, thyroid and uterine
cancers. Leukaemia, lymphomas and cancers of the lymphatic
system, such as Hodgkin's disease, can also be treated.
Biological therapies are a group of treatments which use
natural substances made by the body's immune system, such as
cytokines, in order to control cell growth, to increase the
body's defences against cancer cells or to boost the
production of antibodies to fight cancer cells.
Substances known as colony-stimulating factors are also used
to help the body recover from the effects of treatment. The
therapies are given by injection. At present, most of them
are still being tested in clinical trials.
Though all types of cancer therapy create side-effects, with
modern methods of management these need not be too
troublesome. Common side-effects, such as nausea and
vomiting, can be managed with anti-sickness drugs. Mouth
ulcers can be prevented by the use of mouth washes and a
pain-killing gel. Unfortunately, the embarrassment of hair
loss is usually only avoided by wearing a wig, thought he
hair will grow back.
therapies, such as homeopathy, herbalism, healing and
acupuncture, are often used in conjunction with conventional
medical treatments for cancer. and, today, some cancer units
actually offer these treatments to patients. They can help
you to relax and to cope with the strain of treatment. at
the same time, they may give you back a feeling of being in
control of your own body.