Meaning of pancreatic cancer: Position explains much of its reputation: a tumor deep behind the stomach can grow quietly until it presses on the bile duct or nearby nerves.

Definition of pancreatic cancer

Pancreatic cancer is a malignant growth arising in the pancreas, the organ lying behind the stomach that makes digestive enzymes and hormones including insulin. Most cases begin in the ducts of the enzyme-producing tissue and are classified as pancreatic ductal adenocarcinoma. A much smaller group starts in the hormone-producing islet cells and behaves as a separate disease with its own outlook.

What are the two main forms?

FeatureExocrine (ductal)Neuroendocrine (islet cell)
Cell of originDuct cells of the enzyme-producing tissueHormone-producing islet cells
Share of casesThe large majorityA small minority
BehaviorUsually fast, invades nerves and vessels earlyOften slow, sometimes over many years
Extra clueNone specificMay secrete hormones, causing low blood sugar or flushing

The common ductal form is an adenocarcinoma, meaning it arises from gland-forming tissue. The rarer form, sometimes called pancreatic endocrine cancer, is staged and treated on entirely different lines, so the distinction is made before anything else is decided.

Why is it usually found late?

The pancreas sits deep in the upper abdomen with no capsule that stretches painfully and no function that fails early enough to raise an alarm. A tumor can reach a substantial size before anything is noticed. What eventually shows up depends on location. A growth in the head of the pancreas squeezes the bile duct, so bile backs up and produces jaundice, yellow skin and eyes, dark urine and pale stools, sometimes without pain at all. Tumors in the body and tail announce themselves later, with gnawing pain that bores through to the back, appetite loss and steady weight loss. New diabetes appearing in an older adult alongside weight loss is another recognized pattern.

What raises the risk?

Tobacco smoking is the strongest modifiable factor. Long-standing chronic pancreatitis, obesity, heavy alcohol use and long-standing diabetes all contribute. Around one case in ten has a familial component, including inherited changes in BRCA2 and the genes behind Lynch syndrome and hereditary pancreatitis, which is why family history is asked about specifically. Screening the general population is not effective, since no test is accurate enough for a disease this uncommon, though surveillance is offered to people with a strong inherited risk. Related biliary tumors such as bile duct cancer can produce a near-identical picture.

Used in a sentence

Imaging revealed a mass in the pancreas concerning for pancreatic cancer.

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Good to know

The common exocrine form of pancreatic cancer, adenocarcinoma, is evaluated and behaves differently from the less common neuroendocrine tumors of the pancreas, so the specific cell type involved shapes how a given case is approached.

Word origin

Where “pancreatic cancer” comes from

Formed from Greek pan, meaning all, and kreas, meaning flesh, an early description of the pancreas as an entirely fleshy organ.

For learning, not diagnosis. This glossary provides general educational information and is not a substitute for advice from a qualified healthcare professional. If you may be experiencing a medical emergency, contact local emergency services.