Stage is the word doctors use to communicate the size of a cancerous tumor and where and how far it has spread. The first place cancer is found in the body is called the primary site or primary tumor. When a cancer spreads to distant parts of the body, it's said to have metastasized.
The TNM system is a standard way of describing the extent of a cancer's growth. It is the most common system used to stage pancreatic cancer. It was developed by the International Union Against Cancer and the American Joint Committee on Cancer (AJCC). Here is what the letters stand for in the TNM system:
T refers to the size of the tumor in the pancreas and whether it has grown into nearby areas.
N refers to whether any lymph nodes in the area of the pancreas contain cancer cells.
M refers to whether the cancer has spread to other, distant organs in the body (metastasized), such as your liver or lungs.
The AJCC TNM classification defines cancers by Roman numbers 0 through IV. To arrive at the stage of your cancer, your doctor first assigns numbers for the T, N, and M groups. These numbers are then combined in a process called stage grouping to give the cancer an overall stage. The lower the number, the less the cancer has spread. The higher the number, the more the cancer has spread. These are the stages of pancreatic cancer and their definitions. Be sure to ask your doctor to help explain your cancer's stage to you:
Stage 0. The tumor is only in the top layer of the pancreatic duct cells and has not invaded deeper. This is usually called pancreatic cancer in situ.
Stage IA. Cancer is only found in the pancreas and is no larger than 2 centimeters across. The cancer has not spread to the lymph nodes or to distant parts of the body.
Stage IB. Cancer is only found in the pancreas and is larger than 2 centimeters across. The cancer has not spread to the lymph nodes or to distant parts of the body.
Stage IIA. The cancer has spread to other areas near the pancreas. It has not spread to nearby lymph nodes, to major blood vessels, or to distant sites.
Stage IIB. The cancer may or may not have spread to nearby areas. It has spread to nearby lymph nodes, but has not spread to nearby major blood vessels or nerves or to distant parts of the body.
Stage III. The cancer has spread to nearby major blood vessels or nerves and may have spread to nearby lymph nodes, but it has not spread to distant sites.
Stage IV. The cancer has spread to organs further away from the pancreas. This might include the liver, lining of the abdomen (called the peritoneum), or the lungs.
Doctors use the TNM system to formally stage pancreatic cancer, but for practical purposes they often use a simpler system when trying to determine the best treatment, dividing these cancers into three groups:
Resectable cancer. These cancers can be surgically removed (resected). This includes many cancers that are still confined within the pancreas or have grown just outside of it.
Borderline resectable cancer. These cancers can be surgically removed but are very close to major blood vessels.
Locally advanced cancer. These cancers are still only in the area around the pancreas, but they cannot be removed completely with surgery, often because they are growing into nearby blood vessels. Because they can't be removed with surgery, they are also called unresectable.
Metastatic cancer. These cancers have spread to distant parts of the body, so they cannot be removed completely with surgery (that is, they are also unresectable). Surgery may still be done, but it's used to relieve symptoms, not cure the cancer.