Human bodies are made up of millions of cells, grouped together to form organs or tissues such as the lungs, liver, muscles and bones. Genes inside each cell order it to grow, work, reproduce and die. Normally these orders are clear, our cells obey and we remain healthy. Sometimes a cell’s instructions get mixed up and it behaves abnormally.
It is important to realise, cancer is not a single disease with a single cause and a single type of treatment. Cancer is a group of diseases that involve the uncontrolled division of cells within the body. This rapid cell growth produces a cluster of cells called a tumour, which interferes with normal tissue structure and function. Tumours can be either benign (non-cancerous) or malignant (cancerous). However, some cancers, like leukaemia, do not form tumours, instead, these cancer cells involve the blood and blood-forming organs and circulate through other tissues where they grow. There are more than 200 different kinds of cancer, each with its own name and treatment. Different types of cancer can behave very differently. For example, lung cancer and breast cancer are very different diseases. They tend to grow at different rates and respond to the various forms of treatment differently. It is for this reason that people with cancer need treatment that is tailored to their particular kind of cancer.
Although a number of cancers share risk factors, most cancers have a unique set of risk factors that are responsible for their onset. Some cancers occur as a direct result of smoking, dietary influences, infectious agents or exposure to radiation, while others may be a result of inherited genetic faults. For many cancers, the causes are unknown. While some of the causes are modifiable through lifestyle changes, some others are inherited and cannot be avoided.
The sooner a cancer is found and treatment begins, the better the chances are for living for many years and minimising the toxicities, dislocation and therapy.