Pancreatic Cancer

The pancreas sits in the upper part of the abdomen, behind the stomach and in front of the spine. It is an organ that helps with digestion and regulates blood sugar. Pancreatic cancer originates from the tissues of the pancreas and is one of the leading causes of cancer-related deaths worldwide. The signs and symptoms of pancreatic cancer are often subtle or absent in its early stages, leading to a delayed diagnosis.

The pancreas is a flat and elongated organ, approximately 6 inches long, and has 2 main functions. These are referred to as the exocrine function and the endocrine function.

Exocrine function

The pancreas contains exocrine cells that produce digestive enzymes to help break down food in the small intestine. As food enters the stomach and small intestine, the body releases hormones such as cholecystokinin and secretin, which signal exocrine cells to release enzymes into the small intestine through the pancreatic duct to aid digestion. Exocrine cells make up about 95% of the pancreas.

Endocrine function

The pancreas also produces hormones such as insulin (lowers blood sugar) and glucagon (raises blood sugar). These are produced by the endocrine cells and are released into the bloodstream to control blood sugar by signaling the body to either store or release glucose as needed.

Tissues and organs in the body are made up of cells that replicate and die in an orderly way. This allows for new cells to replace old or damaged cells. When cells become abnormal and grow uncontrollably without dying, they can develop into cancers.

Pancreatic cancer is known to be a solid cancer, as it forms an abnormal mass in the pancreas. Solid cancers originate in tissues and organs as opposed to liquid cancers, which can develop in blood, bone marrow or lymph nodes.

Pancreatic cancer can develop from either exocrine cells or endocrine cells. However, over 90% of pancreatic cancer cases originate from the exocrine part of the pancreas, particularly from cells lining the pancreatic ducts.

Pancreatic exocrine tumors

Exocrine tumors make up over 90% of pancreatic cancers, of which the most common type is called adenocarcinoma. It originates from the exocrine cell lining in the pancreatic ducts. Less common types include acinar cell carcinoma, squamous cell carcinoma and undifferentiated pancreatic carcinoma.

Neuroendocrine pancreatic cancer

Cancer that arises from hormone-producing endocrine cells are known as neuroendocrine pancreatic cancer. This less commonly occurring tumor typically grows more slowly and can act differently from exocrine tumors.

During the development of pancreatic cancer, tumor cells can break away and spread to nearby tissues and organs, forming new cancer colonies. This process of spreading, known as metastasis, causes about 90% of deaths from pancreatic cancer. Once the metastatic cancer cells settle, they are surrounded by normal tissue and have enough space and nutrients to grow.

Learn more: Stages of Pancreatic Cancer

Pancreatic cancer often does not show symptoms in its initial stages, and only roughly 15% of pancreatic cancers are caught early. The difficulty of early diagnosis partially explains the high mortality rate of the disease. Researchers are studying early detection methods using blood-based biomarkers, liquid biopsies and enhanced imaging techniques to detect the disease when more treatment options are available.

Learn more: How to Test for Pancreatic Cancer

Many patients with pancreatic cancer are asymptomatic. Pancreatic tumors can progress rapidly, and by the time symptoms such as weight loss, jaundice, or pain appear, patients can already be in their advanced stages.

Currently, there is a lack of affordable and accurate methods for pancreatic cancer screening. Existing screening approaches are primarily aimed at high-risk individuals and rely on costly techniques such as endoscopic ultrasound (EUS) and magnetic resonance imaging (MRI).

Learn more: How is Pancreatic Cancer Diagnosed

Additionally, pancreatic cancer has a low incidence rate and represents only 3% of all cancer cases in the US. Studies show that the majority of pancreatic cancers occur in individuals without any known family history or genetic predispositions. Screening programs targeting high-risk groups would overlook this portion of individuals who develop pancreatic cancer.

However, hereditary genetic screening is recommended for all patients with pancreatic cancer. Guidelines recommend genetic screening to evaluate for hereditary genes (as that can influence the patient's care or for their family), regardless of a family history or not.

Learn more: Pancreatic Cancer Symptoms

Many pancreatic tumors have dense connective tissue, blood vessels and inflammatory cells that act as a barrier, blocking treatment from penetration. This makes pancreatic tumors more resistant to drugs, and common treatment options such as chemotherapy and radiotherapy are less effective. Clinical research is focusing on testing newer approaches, such as nanoparticle delivery systems and different drug combinations, to increase drug delivery to tumor cells.

Learn more: Pancreatic Cancer Treatments

Pancreatic cancer is one of the most aggressive cancers with a five-year survival rate of less than 10% for most patients when the cancer is diagnosed at later stages. This is due to cancer's ability to quickly invade surrounding tissues and spread to distant organs, and high chances of the cancer returning even after a surgery. In addition, some types of pancreatic cancer have high resistance to treatments such as chemotherapy and radiotherapy.

Pancreatic cancer patients that do get a resection have a five-year survival rate close to 45%. All stages combined, the overall survival rate is 13%.

Researchers are studying the tumor’s biology to understand how cancer cells evade the immune system and resist treatment.

Learn more: Pancreatic Cancer Survival Rates