What is cancer?

Cancer is a disease of the cells in our body and is generally named after the organ or cell where the disease starts. For example, lung cancer begins in the cells in the lung.

All the cells in our body are constantly growing, dividing, dying and being replaced in a controlled way. Cancer occurs when normal cells grow and change in an abnormal and uncontrolled way.

When groups of these cancer cells continue to grow, they can form a lump called a tumour. Doctors can take a biopsy, which involves removing some cells from the tumour and looking at them under a microscope to see if they're cancerous or not.

Tumours can be benign or malignant. Benign means that the tumour is not cancer. These tumours can cause problems where they occur, but it is unlikely that they will spread to other parts of the body.

Malignant means that the tumour is cancerous. Malignant tumours can spread to other parts of the body.

They can spread by growing into surrounding tissue and organs, they can spread through our blood, or through our lymphatic system.

Cancer may be described as being primary or secondary. Primary is where the cancer started.

Secondary cancer, also called metastasis, is cancer that has spread to another part of the body.

The most common types of cancer for people in Ireland are: skin cancer, prostate cancer, breast cancer, lung cancer, and bowel cancer.

Abnormal cells may also occur in our bone marrow, where our blood cells are made. These types of cancers are called blood cancers. For example, leukaemia.

Children's cancers are very rare. The most common cancer types for children are brain tumours, blood cancers, and lymphomas, which are cancers of the lymphatic system.

The main treatments for cancer are: Surgery to remove the tumour. Chemotherapy, which are drugs used to cure and control cancer. Radiotherapy, which uses high-energy rays to kill cancer cells. Targeted and immunotherapies, which are drugs that target certain parts of the cancer cells. Some people may have a combination of these treatments.

Cancer may come back, months or even years after treatment. It can recur in the same place as the original cancer or it may spread to other areas of the body.

Cancer affects 1 in 3 people in Ireland. However, more people are surviving cancer than ever before.

Often, we don't know why cancer develops. Some of the risk factors are things we can't control, such as our age or having a family history of cancer.

There are other risk factors we can control, such as exposure to harmful substances or chemicals, also called carcinogens.

Many cancers can be cured or controlled, and fortunately, research and science are improving outcomes for cancer all the time. We now know that 4 out of 10 cancers can be prevented.

There are simple steps that we can all take to reduce our risk of developing cancer, such as: not smoking, eating healthily, exercising, watching our weight, and limiting our alcohol intake.

Spotting cancer early is important. Learn what to look for and check your body for changes. Talk to your doctor if you notice anything unusual for you.

For more information about cancer, go to our website: cancer.ie/about-cancer

You can also call our Support Line free of charge and talk to one of our cancer nurses on 1800 200 700

Or you can email our cancer nurses at: supportline@irishcancer.ie