The stage of a cancer is a term used to describe its size and whether it has spread beyond the area of the body where it started. Knowing the extent of the cancer helps the doctors to decide on the most appropriate treatment.

Generally, pancreatic cancer is divided into four stages: small and localised (stage one); spread into surrounding structures (stages two or three); or spread into other parts of the body (stage four). If the cancer has spread to distant parts of the body this is known as secondary cancer (or metastatic cancer).

A commonly used staging system is described below.

• Stage 1 This is the earliest stage. The cancer can only be found inside the pancreas itself, although it may be quite large. There is no cancer in the lymph nodes close to the pancreas and no sign that it has spread to anywhere else in the body.

• Stage 2 The cancer has started to grow into the duodenum or bile duct, or other tissues or organs close to the pancreas. There is no cancer in the nearby lymph nodes.

• Stage 3 The cancer can be any size and may have spread into the tissues surrounding the pancreas.

• Stage 4 These cancers are divided into 4A and 4B.

4A means the cancer has grown into organs close to the pancreas, such as the stomach, spleen, large bowel or large blood vessels nearby. Cancer may or may not be present in the lymph nodes.

4B means the cancer has spread to other body organs such as the liver or lungs.

TNM staging system

Another staging system known as the TNM system is commonly used. This can give more precise information about the extent of the cancer.

• T describes the size of the tumour.
• N describes whether the cancer has spread to the lymph nodes.
• M describes whether the cancer has spread to another part of the body (secondary or metastatic cancer).