Correctly identifying pancreatic cancer stages also helps determine the odds of recovery. Pancreatic cancer staging is a particularly complex process that may involve additional tests and surgery after diagnosis. Endoscopic ultrasound (EUS), an imaging test that works by bouncing sound waves off internal tissues or organs, is often used for staging. EUS involves a small probe placed at the end of an endoscope (a thin, flexible tube) and threaded through the mouth, esophagus, and stomach and into the small intestine, close to the pancreas. Doctors may use this technique to take a sample of the tumor tissue, which can then be examined under a microscope and used to gauge the cancer’s aggressiveness. CT scans, which create detailed cross-sectional images of the body, may be used to see if cancer has spread from the pancreas to other organs. RELATED: After a Cancer Diagnosis Comes the ‘Staging’
Staging: Two Different Commonly Used Methods
Doctors generally rely on two different systems for staging pancreatic cancer:
Surgical resection staging This method focuses on whether the cancer can be resected (surgically removed) and where it has spread. Complete surgical resection of pancreatic cancer leads to the best long-term prognosis.TNM (tumor, node, metastasis) This system categorizes cancer into one of five stages ranging from 0 to 4. The determination of which stage best describes a tumor depends on how big the tumor is and whether it has grown into nearby blood vessels; whether or not it has spread to nearby lymph nodes; and whether it has metastasized (spread) to distant sites. A stage 0 tumor is the least advanced, while stage 4 pancreatic cancer is the most advanced.
A Surgery-Focused Staging System
For surgical resection staging, doctors put the cancer in one of three categories:
Resectable A cancer is classified as resectable if it hasn’t spread beyond the pancreas, or has only spread beyond it in a very limited way. While some cancers may initially be classified as resectable on the basis of imaging tests, surgery may reveal that the disease has in fact spread more significantly. If that happens, the surgeon will stop the operation in order to avoid potential side effects.Borderline resectable The tumor has grown into neighboring structures or blood vessels, but the surgeon believes it can still be completely removed. Shrinking the tumor before surgery with chemotherapy or radiation may allow it to be resected without leaving any visible tumor behind.Unresectable The cancer can’t be entirely removed surgically, either because it is locally advanced (meaning it has grown into or has surrounded major blood vessels or nearby organs) or because it has metastasized to distant organs. (1)
The Pancreatic Cancer Action Group, a nonprofit that supports research, clinical initiatives, patient services, and advocacy, claims that between 30 and 50 percent of patients who are viable candidates for surgery are told, incorrectly, that their cancer is unresectable. The group urges patients to see a highly experienced surgeon — one who performs more than 15 pancreatic operations per year — for accurate staging and the best shot at recovery. (2)
The TNM System for Staging Cancer: From 0 to 4
Doctors use the TNM system to stage cancers of all kinds. In the case of pancreatic cancer, it is used for the most common type of pancreatic cancer, pancreatic exocrine cancer. With the TNM system, “T” stands for tumor; “N” stands for node (as in lymph node); and “M” stands for metastasis. Doctors stage each cancer according to factors such as how big the tumor is and where, whether or not it has spread to lymph nodes and how far from the site of the tumor it has spread, and whether or not it has metastasized and how much.
Stage 0 Also called carcinoma in situ, this stage occurs when there are abnormal cells in the lining of the pancreas but none in deeper tissue.Stage 1 Cancer is confined to the pancreas. The cancer is considered stage 1A if the tumor is 2 centimeters (cm) or smaller in diameter, and stage 1B if the tumor is between 2 and 4 cm.Stage 2 In stage 2A, the tumor is larger than 4 cm. In stage 2B, the tumor is larger than 2 cm and has spread to 1 to 3 nearby lymph nodes.Stage 3 The tumor has spread to 4 or more nearby lymph nodes or the major blood vessels near the pancreas.Stage 4 The cancer has spread to distant tissues and organs, such as the lungs, liver, or the peritoneal cavity (containing most of the organs in the abdomen). (3)
Doctors may also describe pancreatic cancer as recurrent if it comes back after treatment, either in the pancreas or in another part of the body, such as the liver. Pancreatic tumors that recur prompt further rounds of tests and scans to learn about the extent of the cancer.
Staging Pancreatic Neuroendocrine Tumors (PNETS)
Pancreatic neuroendocrine cancers (PNETs) make up less than 5 percent of all pancreatic cancers. They have their own staging categories, based on the TNM system.
Stage 1 The tumor is less than 2 cm across and is limited to the pancreas.Stage 2 The tumor is between 2 and 4 cm or more than 4 cm and is still just in the pancreas; or it has grown into the first part of the small intestine or the common bile duct.Stage 3 The tumor has grown into nearby organs or large blood vessels or it has spread to nearby lymph nodes.Stage 4 The cancer has spread to distant parts of the body. (4)
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Is Pancreatic Cancer Curable?
Increasing pancreatic cancer survival is the goal of medical researchers around the world. Pancreatic cancer, particularly the exocrine kind, is a life-threatening cancer, with a five-year survival rate of 8 percent. When this cancer is diagnosed at an early stage, when malignant cells have not yet spread and the tumor can be removed surgically, the five-year survival rate is 32 percent. Roughly 1 in 10 patients are diagnosed at this stage. If the cancer has spread to surrounding tissues or organs, the five-year survival rate is 12 percent. A little more than half (52 percent) of all patients receive their diagnosis when the cancer has already metastasized to a distant part of the body. (5) Experts emphasize that these numbers are only averages and that some people live a lot longer than these statistics suggest. Age, overall health, and a person’s individual response to treatment can all affect pancreatic cancer life expectancy.
