What is cancer?

Cancer is a word that disturbs most people. Cancer is a disease of the body's cells. It starts in our genes. Our bodies are constantly making new cells to enable us to grow, to replace worn out cells, or to heal damaged cells after injury. The process is controlled by certain genes. All cancers are caused by damage to these genes. This damage usually happens during our lifetime, although a small number of people inherit a damaged gene from a parent when they are born. Normally, cells grow and multiply in an orderly way. However, damaged genes can cause them to behave abnormally. They may grow into a lump which is called a tumour.

Tumours can be benign, not cancerous, or malignant, cancerous. Benign tumours do not spread outside their normal boundary to other parts of the body. A malignant tumour is made up of cancer cells. When it first develops, this malignant tumour may be confined to its original site, a cancer-in-situ or carcinoma-in-situ. If these cells are not treated they may spread beyond their normal boundaries and into surrounding tissues (invasive cancer).

For a cancer to grow bigger than the head of a pin, it must grow its own blood vessels. This is called angiogenesis.

Sometimes cells move away from the original, primary, cancer and invade other organs. When these cells reach a new site they may continue to grow and form another tumour at that site. This is called a secondary cancer or metastasis. In some cancers, it is the body's blood cells which multiply abnormally. These cancers are called leukaemia, myeloma and lymphoma.

How is cancer treated?

Treatment for cancer depends on the type of cancer you have, where it began and whether it has spread to other parts of the body. It may also depend on such things as your age, general health and the type of treatment you choose to have.

Most cancers are treated by surgery, chemotherapy or radiotherapy. Other treatments that can work with some cancers are immunotherapy and hormone therapy. Often more than one of these treatments are used for a particular cancer.

What is chemotherapy?

Chemotherapy is the use of special cytotoxic drugs to treat cancer by killing or slowing the growth of cancer cells. Chemotherapy mainly kills rapidly growing cells, like cancer cells. Other rapidly growing cells can also be affected, like the cells involved in causing hair to grow.

There are many different types of chemotherapy drugs and in most chemotherapy treatments a number of drugs are given at the same time. Sometimes only one drug is used. The aim of chemotherapy is to cure or control cancer, to relieve symptoms, or to help other treatments.

How is chemotherapy given?

The way you have your chemotherapy will depend on the drugs and regime used. Chemotherapy drugs are generally given intravenously. The quickest way is through a needle inserted into a vein. This will only take a few minutes. The drugs go into your body through a plastic tube called a catheter inserted into a vein in your arm or hand.

Some people have veins which are difficult to find or are scarred from previous treatments and may have a catheter surgically placed under the skin on their chest. This is called a venous access device (VAD) or central line (CL), which can stay inserted until your course of treatment is finished. Your doctors and nurses will discuss this with you if required for your treatment.

Chemotherapy can also be given, in some instances, orally as tablets or via other routes in the body. Your chemotherapy nurse will discuss the exact nature of your particular medications on your first visit and answer any questions you may have. Remember the oncology team looking after you are always available to talk to you about your treatment.

How long will I have chemotherapy for?

There are many different types of chemotherapy. Some take longer to administer than others. One of the chemotherapy nurses will sit down and discuss the details of your particular treatment on your first visit.

When you have chemotherapy there will often be a period of treatment followed by a rest. The number of treatments and their frequency will depend upon the type of cancer and the drugs used. In general chemotherapy is given over six to 12 months. However, it may be given for shorter or longer periods.

The above information includes extracts from the Cancer Council of New South Wales Information Booklets.