How is pancreatic cancer staged?
The stage of a pancreatic cancer (extent of disease at diagnosis) is the most important factor in choosing treatment options and predicting a patient's outlook. The tests described in the section “How is pancreatic cancer diagnosed?” are the ones used to determine the stage of the cancer.
The American Joint Committee on Cancer (AJCC) TNM staging system
A staging system is a standardized way in which the cancer care team describes the extent that a cancer has spread. The main system used to describe the stages of cancers of the pancreas is the American Joint Committee on Cancer (AJCC) TNM system. The TNM system for staging contains 3 key pieces of information:
- T describes the size of the primary tumor(s), measured in centimeters (cm), and whether the cancer has spread within the pancreas or to nearby organs.
- N describes the spread to nearby (regional) lymph nodes.
- 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:
- The numbers 0 through 4 indicate increasing severity.
- The letter X means "cannot be assessed" because the information is not available.
- The letters "is" mean "carcinoma in situ," which means the tumor is contained within the top layers of pancreatic duct cells and has not yet invaded deeper layers of tissue.
TX: The main tumor cannot be assessed.
T0: No evidence of a primary tumor.
Tis: Carcinoma in situ (very few pancreatic tumors are found at this stage)
T1: The cancer has not spread beyond the pancreas and is smaller than 2 cm (about ¾ inch) across.
T2: The cancer has not spread beyond the pancreas but is larger than 2 cm across.
T3: The cancer has spread from the pancreas to surrounding tissues near the pancreas but not to major blood vessels or nerves.
T4: The cancer has extended further beyond the pancreas into nearby large blood vessels or nerves.
NX: Regional lymph nodes cannot be assessed.
N0: Regional lymph nodes (lymph nodes near the pancreas) are not involved.
N1: Cancer has spread to regional lymph nodes.
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: Distant metastasis is present.
Stage grouping for pancreatic cancer
After the T, N, and M categories of the cancer have been determined, this information is combined to assign a stage, which is expressed in Roman numerals I through IV. The process of assigning a stage number based on TNM stages is called stage grouping.
Stage 0 (Tis, N0, M0): The tumor 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 tumors are sometimes referred to as pancreatic carcinoma in situ or pancreatic intraepithelial neoplasia III (PanIn III).
Stage IA (T1, N0, M0): The tumor is confined to the pancreas and is less than 2 cm in size. It has not spread to nearby lymph nodes or distant sites.
Stage IB (T2, N0, M0): The tumor is confined to the pancreas and is larger than 2 cm in size. It has not spread to nearby lymph nodes or distant sites.
Stage IIA (T3, N0, M0): The tumor is growing outside the pancreas but not into large blood vessels. It has not spread to nearby lymph nodes or distant sites.
Stage IIB (T1-3, N1, M0): The tumor is either confined to the pancreas or growing outside the pancreas but not into nearby large blood vessels or major nerves. It has spread to nearby lymph nodes but not distant sites.
Stage III (T4, Any N, M0): The tumor is growing outside the pancreas into nearby large blood vessels or major nerves. It may or may not have spread to nearby lymph nodes. It has not spread to distant sites.
Stage IV (Any T, Any N, M1): The cancer has spread to distant sites.
Although not formally part of the TNM system, other factors are also important in determining prognosis (outlook). The grade of the cancer (how abnormal the cells look under the microscope) is sometimes listed on a scale from G1 to G4, with G1 cancers looking the most like normal cells and having the best outlook.
For patients who have surgery, another important factor is the extent of the resection — whether or not all of the tumor is removed. This is sometimes listed on a scale from R0 (where all visible and microscopic tumor was removed) to R2 (where some visible tumor could not be removed).
Terms commonly used to describe pancreatic cancer
From a practical standpoint, how far the cancer has spread often can't be determined accurately until surgery. That's why doctors use a simpler staging system, which divides cancers into groups based on whether or not it is likely they can be removed surgically. These groups are called resectable, locally advanced (unresectable), and metastatic. These terms are used to describe both exocrine and endocrine pancreatic cancers.
If the cancer is only in the pancreas (or has spread just beyond it) and the surgeon can remove the entire tumor, it is called resectable.
Locally advanced (unresectable)
If the cancer has not yet spread to distant organs but it still can't be completely removed with surgery, it is called locally advanced. Often the reason the cancer can't be removed is because too much of it is present in nearby blood vessels. Since the cancer cannot be removed entirely by surgery, it is also called unresectable. For these tumors, surgery would only be done to relieve symptoms or problems like a blocked bile duct or intestinal tract.
When the cancer has spread to distant organs, it is called metastatic. Surgery may still be done, but the goal would be to relieve symptoms, not to cure the cancer.
Last Medical Review: 01/28/2013
Last Revised: 09/06/2013