What is Cancer?
What is Cancer?
Cancer is a generic name given to a group of diseases that involve uncontrolled multiplication of abnormal cells. This usually results in the area growing in size, affecting the original and adjacent organs and often results in the spread of the cancer to other sites of the body.
Some growths (tumours) are benign, while others are malignant. Cancers are malignant growths.
Benign tumours do not spread but they may cause a lump or put pressure on parts of the body near the tumour. They are often cured by surgical removal. Occasionally, radiation treatment may be given to stop the growth or reduce the risk of the tumour coming back after surgery.
Primary and Secondary Tumours
Malignant tumours (cancer) are usually more active then benign tumours and tend to spread and invade other tissues. The original cancer site is called the primary tumour. If the cancer spreads (metastasises) to other organs or tissues, the cancerous areas are known as secondary tumours (metastases).
Under the microscope, secondary cancers usually appear the same as the cells at the primary site, even though they are located elsewhere in the body.
Malignant tumours may be 'solid' or 'liquid'. 'Liquid' cancers are those involving the blood, such as leukaemia. Solid tumours may arise from any organ. In Australia, the most common cancers are breast cancer, bowel cancer, and melanoma (skin cancer) in females. In males, prostate cancer is the most common, followed by bowel cancer then melanoma (skin cancer).
Different cancers have different tendencies in behaviour, in terms of growth rates, organs where they tend to spread as secondary cancers and response to treatment.
Treatment depends on a number of factors, such as:
- The type of cancer and the organ in which the tumour is located
- The rate of growth
- The staging (a process in which doctors classify the size, site and spread of a tumour)
- The patient's own characteristics, such as age, general health, medical conditions and their personal preference.
Treatment often involves a combination of therapies, such as surgery, radiation therapy, chemotherapy, hormonal therapy and other supportive measures.