Some cancers are very common and others are very rare. The most recent statistics for the UK (from 2003) show that for men the most common cancer is prostate cancer (23%), followed by lung cancer (16%), large bowel cancer (14%) and bladder cancer (5%).

For women the figures are breast cancer (31%), large bowel cancer (11%), lung cancer (11%) and cancer of the ovary (5%).

Many people with cancer can be cured. Even if a cancer cannot be cured, it can often be controlled with treatment for months or years.

Cancer may come back after treatment which is known as a recurrence or secondary cancer depending on whether it is in the same part of the body or not.

There are six main types of treatment for cancer and these are described below. It is fairly common for a combination of treatments to be used.

Active surveillance (or watchful waiting)

Some types of cancer grow very slowly and may cause no problems for many years. In this situation you may not need to have any treatment for some time, but your doctor will monitor you closely so that if the cancer does start to grow you can be given treatment at that time.

Surgery

An operation is done to remove the tumour. Surgery is often used if the cancer is only in one area of the body and has not spread. It may be used to remove lymph nodes if these are also affected by the cancer. It can sometimes be used to remove a cancer that has spread to another area of the body, but this is less common. The type of operation will depend on the area of the body affected by the cancer, and on the size and position of the tumour.

Radiotherapy

This is the use of high energy x-rays to destroy cancer cells, but cause as little harm as possible to normal cells. The radiotherapy is aimed at the affected area of the body and is very carefully planned. It can cause side effects and the most common is tiredness. The side effects will depend on the part of the body that is being treated.

Chemotherapy

Chemotherapy is the use of anti-cancer (cytotoxic) drugs to destroy cancer cells. There are more than 50 different chemotherapy drugs. Some are given as tablets or capsules but most are given by drip (infusion) into a vein. The drugs go into the bloodstream and travel throughout the body to treat the cancer cells wherever they are. Sometimes just one chemotherapy drug is used, but often a combination of two, three or more drugs is given.

Chemotherapy can cause side effects. The side effects will depend on which drug (or combination of drugs) is used. There are now very good ways of preventing or reducing the side effects of chemotherapy.

Hormonal therapy

Hormonal therapies work by altering the levels of particular hormones in the body. Some cancers depend on certain hormones in order to divide and grow. By altering the level of hormones in the body, or blocking the hormones from attaching to the cancer cells the cancer can be controlled.

Biological therapy

Biological therapies use substances that occur naturally in the body to destroy cancer cells. There are several types of biological therapy, including: monoclonal antibodies, cancer growth inhibitors, vaccines and gene therapy.

Monoclonal antibodies are drugs that can 'recognise' and find specific cells in the body. They can be designed to find a particular type of cancer cell, attach itself to them and destroy them. They can also carry a radioactive molecule, which then delivers radiation directly to the cancer cells.

Cancer growth inhibitors interfere with the way cancer cells use 'chemical messengers' to help the cell to develop and divide.

Research is trying to see whether vaccines and gene therapy can be given to treat a cancer that has come back or has spread. Vaccines may also be able to reduce the chance of a cancer coming back, but this type of research is in the very early stages.

We have further information on all the cancer treatments mentioned above and also onclinical trials.