Pancreatic Cancer: Types and Stages

Stages and Types of Pancreatic Cancer

This section covers the following topics:

Types of pancreatic cancer

The pancreas helps your body break down food, and especially the fat in your diet and turn it into energy. It is also critical for controlling sugar levels and preventing diabetes. The pancreas has two main types of cells:

• Exocrine cells make and release chemicals known as enzymes into your small intestine to help your body digest food.
• Endocrine cells make hormones, including insulin, which controls the amount of sugar in your bloodstream. These cells are also called Islet cells. 

Pancreatic exocrine cancers  

These are the most common type of pancreatic cancer. They are also the type most associated with inherited mutations. 

• Most pancreatic exocrine cancers start in the ducts. They are called ductal adenocarcinomas.
• Other, more rare exocrine cell cancers include: acinar cell carcinoma, adenosquamous carcinoma, colloid carcinoma, giant cell tumor, hepatoid carcinoma, mucinous cystic neoplasms, pancreatoblastoma, serous cystadenoma, signet ring cell carcinoma, solid and pseudopapillary tumors, squamous cell carcinoma, and undifferentiated carcinoma.

Stages of pancreatic exocrine cancer

The stage refers to whether the cancer has spread, and if so, where in the body the cancer has spread. Identifying the stage of pancreatic cancer helps doctors decide how to treat it. In pancreatic cancer, staging is done using imaging tests before surgery, to group the cancer into one of the following stages: 

• Resectable tumors appear on imaging to be completely removable with surgery. About 20% of pancreatic exocrine cancers fall into this category. 
• Unresectable tumors may be locally advanced tumors. These cannot be removed by surgery because they have invaded the nearby blood vessels. Locally advanced tumors have not spread to other organs.  
• Metastatic tumors are those that have spread to other organs outside of the pancreas. Metastatic tumors are also considered unresectable. 
• With borderline resectable tumors, the doctor cannot tell from imaging if the tumor has spread to the blood supply or other organs, or if the tumor appears to touch important structures in a limited fashion.

Intraductal papillary mucinous neoplasms (IPMN)

Intraductal papillary mucinous neoplasm (IPMN) is an abnormal growth within the ducts of the pancreas. If left without treatment, some may become cancerous. As more people are being screened for pancreatic cancers, more IPMNs are being found.

IPMNs are distinguished by the part of the pancreas where they arise.

• Main duct type IPMNs arise from the main duct of the pancreas. These IPMNs tend to be more aggressive and are more likely to turn into cancer than branch duct IPMNs. Main duct IPMNs are often surgically removed. 
• Branch duct IPMNs start in the branches of the pancreatic duct. Many of these IPMNs never turn into cancer. Branch duct IPMNs become more concerning if they have any of the following features:
  • are growing over time
  • are larger than 3 cm
  • are causing dilation in the main duct of the pancreas
  • contain a solid mass
  • are causing symptoms

Pancreatic endocrine cancers

Endocrine cell cancers are more rare than exocrine cell cancers. They form in the cells that make hormones that are necessary to control blood sugar and other metabolic functions. They may also be called islet cell tumors, or pancreatic neuroendocrine tumors (PNETs). Endocrine cell cancers are treated based on their stage, grade and tumor type. Inherited mutations in CDKN1B, MEN1, NF1, TET and VHL are linked to increased risk for PNETs.

Pancreatic neuroendocrine tumor staging

Measuring the stage of the cancer can help doctors decide on the best way to treat it.