About Cancer

What is cancer?

Cancer is a term used for diseases in which abnormal cells divide without control. Cancers begin growing locally in the body and can spread through the blood and lymph systems and destroy healthy cells.

Some tumours are benign (meaning they are not cancererous) and these are usually not dangerous.  A tumour is malignant when it is able to spread to other parts of the body. A doctor can tell if a tumour is benign or malignant by taking a piece of it (a biopsy) and looking at it under a microscope.

Where the cancer cells first start is called a primary tumour.  Some cells can break from the primary tumour and move to another part of the body.  When this happens, a new tumour can form in a different part of the body which is called a secondary tumour.  When a tumour spreads in this way it has ‘metastasised’.

How common is cancer?

Cancer is a common condition. Around 33,000 new cases are diagnosed in Ireland each year. More than one in three people will get some form of cancer during their lifetime.However, survival for some common cancers is getting better because of more awareness, screening, finding cancer early and better treatments.

What types of cancer are there?

There are more than 100 different types of cancer. Cancers are usually named after the part of the body where the cancer first began. For example, cancer that begins in the breast is called breast cancer; cancer that begins in the prostate is called prostate cancer. The name does not change even if the cancer spreads to another part of the body.

Different types of cancer will have different signs and symptoms. They also are different in how quickly they grow, how they spread, and how they respond to treatment. So it is important to get a correct diagnosis, so that the best treatment can be given.

What causes cancer?

All cancers begin in cells. A cell is the basic unit of life of the body. The body is made up of many different types of cells. These cells grow and multiply in a controlled way to keep the body healthy. Normally, when cells become old or damaged, they die and are replaced with new cells.

tumour cells

(Picture from Macmillan website)

This normal cell renewal process can go wrong sometimes. A cell may become damaged, which results in changes that affect normal cell renewal. When this happens cells do not die when they should. This may lead to cells forming a lump called a tumour, or blood cells can become damaged and lead to leukaemia.

You can get cancer at any age, but the risk of cancer increases as you get older. One of the main risks for causing cancer is tobacco smoke. Other risks include lifestyle choices, radiation, chemical exposure, hormones, or other factors within the body and environment.

How can I spot cancer?

Some changes to your body can be a sign of cancer and it is important to get them checked out by a doctor. You need to become familiar with your own body so that you are aware of any changes that might be a concern.  Finding cancer early can save your life.  You should contact your GP if you have any concerns.

Read more information on cancer prevention available here.