Stages and subtypes 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  

Exocrine cell cancers are the most common type of pancreatic cancers.

• Most pancreatic exocrine cancers start in the ducts, and are called ductal adenocarcinomas.
  • Intraductal papillary mucinous neoplasm (IPMN) is a precancerous abnormal growth within the ducts of the pancreas. If left without treatment, it can become cancerous. (IPMN). In some cases, an IPMN may be found along with an invasive cancer. As more people are being screened for pancreatic cancers, more IPMNs are being found.
• 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.

Staging of pancreatic exocrine cancers

The stage of a cancer 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. 

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 (NETs). Endocrine cell cancers are treated based on their stage, grade and tumor type. 

Genetic testing and biomarker testing  

Additional tests, including genetic testing for an inherited mutation and tumor biomarker testing may help identify people who are eligible for targeted therapy, immunotherapy or clinical trials.