Staging Pancreatic Cancer

The stage of a cancer tells a doctor how advanced the cancer is, and can help to provide information and guidance regarding the most appropriate course of treatment. The investigations performed immediately after diagnosis, or which are repeated after a course of treatment has been completed, provide the information to allow staging. Staging is not an exact science, and is limited by the sensitivity of the tests, but it is nonetheless useful in reaching management decisions.

Please do not feel that you need to read beyond this point!! What follows is technical, and is mainly of interest to healthcare professionals.

There are different systems of staging cancers. The two in most common use are the TNM system and number system.

The American Joint Committee on Cancer (AJCC) TNM staging system (TNM version 7):

The TNM system is based on 3 key pieces of information:

  1. T describes the size of the main (primary) tumour and whether it has grown outside the pancreas and into nearby organs.
  2. N describes the spread to nearby (regional) lymph nodes.
  3. M indicates whether the cancer has metastasized (spread) to other organs of the body. (The most common sites of pancreatic cancer spread are the liver, lungs, and the peritoneum — the space around the digestive organs.)

Numbers or letters appear after T, N, and M to provide more details about each of these factors.

T categories:

  • TX: The main tumour cannot be assessed.
  • T0: No evidence of a primary tumour.
  • Tis: Carcinoma in situ (the tumour is confined to the top layers of pancreatic duct cells). (Very few pancreatic tumours are found at this stage.)
  • T1: The cancer is still within the pancreas and is 2 centimeters (cm) (about ¾ inch) or less across.
  • T2: The cancer is still within the pancreas but is larger than 2 cm across.
  • T3: The cancer has grown outside the pancreas into nearby surrounding tissues but not into major blood vessels or nerves.
  • T4: The cancer has grown beyond the pancreas into nearby large blood vessels or nerves.

N categories:

  • NX: Nearby (regional) lymph nodes cannot be assessed.
  • N0: The cancer has not spread to nearby lymph nodes.
  • N1: The cancer has spread to nearby lymph nodes.

M categories:

  • M0: The cancer has not spread to distant lymph nodes (other than those near the pancreas) or to distant organs such as the liver, lungs, brain, etc.
  • M1: The cancer has spread to distant lymph nodes or to distant organs.

 

“Staging” for pancreatic cancer

Once the T, N, and M categories have been determined, this information is combined to assign an overall stage of 0, I, II, III, or IV (sometimes followed by a letter). This process is called stage grouping.

Stage 0 (Tis, N0, M0): The tumour is confined to the top layers of pancreatic duct cells and has not invaded deeper tissues. It has not spread outside of the pancreas. These tumours are sometimes referred to as pancreatic carcinoma in situ or pancreatic intraepithelial neoplasia III (PanIn III).

Stage IA (T1, N0, M0): The tumour is confined to the pancreas and is 2 cm across or smaller (T1). It has not spread to nearby lymph nodes (N0) or distant sites (M0).

Stage IB (T2, N0, M0): The tumour is confined to the pancreas and is larger than 2 cm across (T2). It has not spread to nearby lymph nodes (N0) or distant sites (M0).

Stage IIA (T3, N0, M0): The tumour is growing outside the pancreas but not into major blood vessels or nerves (T3). It has not spread to nearby lymph nodes (N0) or distant sites (M0).

Stage IIB (T1-3, N1, M0): The tumour is either confined to the pancreas or growing outside the pancreas but not into major blood vessels or nerves (T1-T3). It has spread to nearby lymph nodes (N1) but not to distant sites (M0). Your doctor may call all of the above “potentially resectable” pancreatic cancer.

Stage III (T4, Any N, M0): The tumor is growing outside the pancreas into nearby major blood vessels or nerves (T4). It may or may not have spread to nearby lymph nodes (Any N). It has not spread to distant sites (M0). Your doctor may call this locally advanced cancer.

Stage IV (Any T, Any N, M1): The cancer has spread to other areas of the body such as the liver or lungs. (M1). Your doctor may call this metastatic cancer.