Primary and secondary brain tumours

Tumours that start in the brain and are called primary brain tumours. Cancer that has spread to the brain from somewhere else in the body is called secondary brain cancer or brain metastases.

It is important to know the difference between primary and secondary brain tumours. This is because the treatment you have depends on where your cancer started.

Primary brain tumours

Primary brain tumours start in the brain. Tumours can start in any part of the brain or the spinal cord. Primary brain tumours can be cancerous (malignant) or non cancerous (benign).

Most malignant brain tumours in adults start in a part of the brain called the cerebrum (forebrain). They can also start in other parts such as the:

• layers of tissue that protect the brain (meninges)
• spinal cord
• pituitary or pineal glands

Most benign brain tumours in adults start in the meninges. They are called meningiomas. 

Secondary brain tumours

Cancers that have spread to the brain from somewhere else in the body are called secondary brain tumours or brain metastases.

Secondary brain cancers are made of the same type of cells as the primary cancer. So, if your cancer started in the lungs, the areas of cancer in the brain are made up of lung cancer cells.

Any type of cancer can spread to the brain. But the most common types are:

• lung cancer
• breast cancer
• kidney cancer
• melanoma skin cancer
• bowel (colorectal) cancer

This happens because cancer cells can break away from the primary cancer and travel through the bloodstream to the brain. There they can grow into new tumours.