What is Cancer?

Pancreatic Cancer Action
Patient Information Booklets

What is Pancreatic cancer and how is it diagnosed?

This booklet for patients and carers describes pancreatic cancer, its causes and symptoms. It gives detailed information on the diagnostic tests used and the stages of pancreatic cancer. It includes a section on what to ask your doctor, where to go for further information and a glossary to explain many of the terms used.

Firstly, what is cancer? All cancers begin with changes in a cell or group of cells. Cells are the basic building blocks of all living things. The body is made up of many types of cells, which usually grow and divide in a controlled way to make more cells. These new cells are needed to keep the body healthy.

When cells become old or damaged, they die and are replaced with new cells. The way a cell grows, divides and dies is controlled by its genes (a short section of DNA). Sometimes DNA gets damaged or changed. If this damage affects genes that tell a cell when to grow, divide or die, cells do not die when they should, and new cells form when the body does not need them.

The extra cells which are made, change the composition of the blood, or forms a lump, called a tumour, which is the beginning of cancer.

See how tumours develop

Not all tumours are cancerous: tumours can be benign or malignant

Benign tumours aren’t cancerous. They can often be removed and, in most cases, do not come back. Cells in benign tumours do not spread to other parts of the body.
Malignant tumours are cancerous. Cells in these tumours can invade nearby tissues and spread to other parts of the body. Sometimes cells move away from the original (primary) cancer site and spread to other organs and bones where they can continue to grow and form another (secondary) tumour at a new site.

This process is called metastasis. Secondary cancers keep the name of the original cancer location. For example, pancreatic cancer that has spread to the liver is still called pancreatic cancer.

Cancer cells are dangerous because they will continue to grow and divide, even if they cause damage to the tissues around them.

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Information Product № PCA0011v1 Published 03/10/2019
Last Updated 08/09/2022 Next Review Due 03/10/2022