x
Cancer Awareness
Cancer is the development of abnormal cells that the body cannot control. It is a disease caused by normal cells changing so that they grow in an uncontrolled way. The uncontrolled growth causes a lump called a tumour to form. If not treated, the tumour can cause problems in one or more of the following ways:
It can affect all parts of the body, which means some types are exclusive to women and others affect only men. Early diagnosis is the key to getting the right treatment.
Our body is made up of billions of tiny cells that can only be seen under a microscope. These cells are grouped together to make up the tissues and organs of our bodies. They are a bit like building blocks. Different types of body tissues are made up of different types of body cells. For example, there are bone cells in bone and breast cells in the breast. Normal body cells have several important characteristics. They can:
This happens very fast between conception and adulthood. But once we are grown up, most cells only reproduce to replace others that have died, for example through injury or illness. Some cells carry on reproducing. These include sperm cells, hair cells, cells in the gut and cells that make blood in the bone marrow.
When more cells are needed by the body, some cells double up to increase their numbers. They do this very precisely so that the new cells are the same as the old ones. Each cell makes copies of all its genes. Then it splits into two with one set of genes in each new cell. If even more cells are needed, these new cells will rest for a while and then reproduce again. The cells will carry on doing this until enough cells have been made.
Cancer cells are cells that grow and divide at an unregulated, quickened pace. Although cancer cells can be quite common in a person they are only malignant when the other cells (particularly natural killer cells) fail to recognize and/or destroy them.
Cancer cells are different to normal cells in several ways. They don't die if they move to another part of the body and:
The cancer cells may be able to stop themselves self-destructing. Or they may self-destruct more slowly than they reproduce, so that their numbers continue to increase. Eventually a tumour is formed that is made up of billions of copies of the original cancerous cell. Scientists describe cancer cells as being 'immortal'.
Something in the cancer cells overrides the normal signalling system. This may be because the genes that tell the cell to reproduce keep on and on sending signals. Or because the genes that normally tell the cell to stop reproducing have been damaged or lost. So, the cancer cell keeps on doubling, regardless of the damage the extra cells cause to the part of the body where the cancer is growing.
Cancer cells can lose the molecules on their surface that keep normal cells in the right place. So, they can become detached from their neighbours.
Different types of cells in the body do different jobs, but they are basically similar. They all have a centre called a nucleus. Inside the nucleus are the genes. Genes are bits of code. The information they carry can be switched on or off. The genes control the cell. They decide when it will reproduce, what it does and even when it will die.
Normally the genes make sure that cells grow and reproduce in an orderly and controlled way. If the system goes wrong for any reason, the usual result is that the cell dies. Rarely, the system goes wrong in a way that allows a cell to keep on dividing until a lump called a 'tumour' is formed.
Genes are coded messages that tell cells how to make proteins. Proteins are the molecules that control the way cells behave. In this way, our genes decide what we look like and how our body works. We have many thousands of separate genes.
Genes are made of DNA and they are in the nucleus of the cell. The nucleus is the cell's control centre. Genes are grouped together to make chromosomes. We inherit half our chromosomes from our mother and half from our father.
Genes tell cells how to behave. They control how our bodies grow and develop. We each have about 25,000 genes. So far scientists have found around 300 that play some part in the development of cancer.
Cancer cells are different from normal cells. They have changes (called faults or mutations) in several of their genes which make them divide too often and form a tumour. The genes that are damaged may be:
All cancers develop because something has gone wrong with one or more of the genes in a cell. But most of these gene changes happen during our lives.
The main reason cancer can be difficult to cure is that it can spread to a different part of the body from where it started. The cancer that grows where it first started in the body is called the 'primary cancer'. The place a cancer spreads to and then starts growing are called the 'secondary cancer' or 'metastasis'.
To spread, some cells from the primary cancer must break away, travel to another part of the body and start growing there. Cancer cells do not stick together as well as normal cells do. They also may produce substances that stimulate them to move.
There are three main ways a cancer spreads:
Blood carries nutrients (food) and oxygen to all the cells of the body, and carries away waste products so that they can be removed from the body. Without a blood supply, cells and body tissues die.
To spread, the cancer cell must first become detached from the primary cancer. It must then move through the wall of a blood vessel to get into the bloodstream. When it is in the bloodstream, it is swept along by the circulating blood until it gets stuck somewhere, usually in a very small blood vessel called a capillary. Then it must move back through the wall of the capillary and into the tissue of the organ close by. There it must start to multiply to grow a new tumour.
This is a complicated journey. Most cancer cells do not survive it. Probably, out of many thousands of cancer cells that reach the blood circulation only one will survive to form a secondary cancer or metastasis.
The way a cancer spreads through the lymphatic system is very like the way it spreads through the bloodstream. The cancer cell must become detached from the primary tumour. Then it travels in the circulating lymph fluid until it gets stuck in the small channels inside a lymph node. There it begins to grow into a secondary cancer.
The lymphatic system is a system of thin tubes that runs throughout the body. These tubes are called lymph vessels or lymphatic vessels.
The immune system is important to cancer patients in many ways because:
Cancer can weaken the immune system by spreading into the bone marrow where the cells that help fight infection are made. This happens most often in leukaemia or lymphoma. But it can happen with other cancers too. Chemotherapy and radiotherapy can weaken immunity by causing a drop in the number of white blood cells made in the bone marrow.
There are two main parts of the immune system:
If you are having cancer treatment, it is important for you to know that
When your blood counts are low, your cancer specialist may want you to take antibiotics to help prevent severe infection.
Your immune system is very unlikely to be able to fight off an established cancer completely without help from conventional cancer treatment, although there are very rare documented cases of cancers just disappearing (spontaneous regression). Some treatments use elements of the immune system to help treat cancer.
Most people feel shocked and upset when they first find out that they have cancer. You may also feel:
You may have some of these feelings. Or you may feel totally different. Everyone reacts in their own way. Sometimes it is hard to take in the fact that you have cancer at all.
Upsetting feelings are a natural part of coming to terms with cancer. All sorts of feelings are likely to come and go. Your family and friends will probably have strong feelings too.
Many people with cancer believe that they should strengthen their immune systems to help beat the disease. There is a commonly held belief that reducing stress can help to strengthen our immune systems. There is some scientific evidence that stress weakens our immunity. While many life stresses cannot be avoided altogether, there are ways of trying not to let things get to you. Many complementary therapies such as meditation, massage and reflexology, can be very relaxing.
We can avoid getting run down and look after our self by:
