Pancreatic cancer is a disease in which cells in the pancreas grow uncontrollably, forming tumors that interfere with digestion and hormone regulation. It is one of the most aggressive cancers, with an overall five-year survival rate that varies dramatically by stage: 43.6% when caught before it spreads, but just 3.4% once it reaches distant organs. The pancreas sits deep in the abdomen behind the stomach, which is part of why this cancer is so difficult to detect early.
What the Pancreas Does
The pancreas has two jobs. Its exocrine cells produce digestive enzymes that break down carbohydrates, proteins, and especially fat. Its endocrine cells release hormones like insulin that regulate blood sugar. When a tumor grows in the pancreas, it can disrupt either or both functions.
Most pancreatic tumors form in the head of the organ, where they block the main duct that carries digestive enzymes to the small intestine. This blockage causes a condition called exocrine insufficiency, meaning food passes through without being properly broken down. Fat digestion is particularly affected, though noticeable malabsorption typically doesn’t happen until enzyme production drops below 5 to 10% of normal levels.
Types of Pancreatic Cancer
Over 90% of pancreatic cancers are ductal adenocarcinomas, which start in the cells lining the ducts that carry digestive enzymes. This is the type most people mean when they say “pancreatic cancer,” and it tends to be fast-growing and difficult to treat.
A much rarer form, pancreatic neuroendocrine tumors, accounts for 2 to 10% of cases. These arise from the hormone-producing cells and generally grow more slowly. Treatment and prognosis differ substantially between the two types.
Symptoms
Pancreatic cancer rarely causes symptoms in its early stages. By the time most people notice something is wrong, the disease has already spread. When symptoms do appear, the most common ones are:
- Jaundice: yellowing of the skin and whites of the eyes, often accompanied by dark urine, light-colored stools, and itching. This happens when a tumor in the head of the pancreas blocks the bile duct.
- Abdominal pain that spreads to the back or sides.
- Unexplained weight loss and loss of appetite.
- New or worsening diabetes that becomes unusually difficult to control.
- Blood clots and persistent fatigue.
Floating stools are another sign worth noting. When the pancreas can’t produce enough enzymes to digest fat, undigested fat ends up in the stool, making it pale, greasy, and buoyant.
Risk Factors
Smoking is the most significant modifiable risk factor. The risk increases in a dose-dependent way, reaching up to 2.7 times higher for people who smoke more than 25 cigarettes per day. Obesity also plays a role: every five-unit increase in BMI during early adulthood (ages 18 to 21) raises the risk by about 20%. A high waist-to-hip ratio is independently associated with a 20 to 30% higher risk.
The relationship between diabetes and pancreatic cancer is complex and runs in both directions. People newly diagnosed with type 2 diabetes have a 14 to 15 times higher chance of being diagnosed with pancreatic cancer in the first year, suggesting the cancer itself may be triggering the diabetes. That risk drops over time but stabilizes at roughly 2.4 times higher than the general population for people with long-standing diabetes.
Heavy alcohol consumption (roughly three or more standard drinks per day) modestly increases risk, by about 36%. Less well known is the connection to gum disease. Periodontitis and certain oral bacteria, particularly the species behind severe gum infections, can increase risk by up to 60%. Significant tooth loss over a four-year period nearly triples the risk.
Several inherited conditions carry dramatically elevated risk. Hereditary pancreatitis increases risk 53-fold. Peutz-Jeghers syndrome, a rare genetic condition causing intestinal polyps, raises it 76-fold. People with Lynch syndrome face an 8.6-fold increase, and familial atypical mole melanoma syndrome carries a 13 to 67-fold increase. Mutations in the BRCA2 gene are found in about 3.7% of families with a strong history of pancreatic cancer, while BRCA1 mutations appear in about 1.2%.
How It Is Diagnosed
There is no routine screening test for pancreatic cancer in the general population. Most cases are found after symptoms prompt imaging studies. CT scans and MRI are commonly used first, but endoscopic ultrasound (EUS) is the most accurate method for detecting pancreatic tumors, especially those smaller than 2 centimeters. During EUS, a thin scope is passed through the mouth into the stomach, where an ultrasound probe can image the pancreas at close range and take tissue samples.
A blood marker called CA 19-9 is sometimes measured, but it has important limitations. About 15% of people with pancreatic cancer have normal CA 19-9 levels, and roughly 10% of white individuals lack the biological machinery to produce this marker at all. CA 19-9 can also be elevated in other conditions, including gallbladder disease, chronic pancreatitis, and other gastrointestinal cancers. Its main clinical value is in tracking how well treatment is working rather than catching the disease early. Higher CA 19-9 levels do tend to correlate with more advanced disease, with median levels roughly eight times higher in stage IV compared to stage I.
Stages and What They Mean
Pancreatic cancer staging determines what treatment is possible. The staging system groups tumors based on size, whether cancer has reached nearby lymph nodes, and whether it has spread to distant organs.
In stages I and II, the tumor is confined to the pancreas or has reached a small number of nearby lymph nodes, but critically, it has not grown into the major blood vessels surrounding the pancreas. These tumors are potentially removable with surgery. Stage III means the cancer either involves major arteries (making surgery impossible) or has spread to four or more lymph nodes. Stage IV means the cancer has metastasized to distant organs, most commonly the liver or lungs.
The survival differences between stages are stark. Localized disease that hasn’t spread beyond the pancreas has a 43.6% five-year survival rate, according to the SEER database. Once cancer reaches regional lymph nodes, that drops to 17%. Distant metastatic disease carries a 3.4% five-year survival rate.
Treatment
Surgery offers the only potential cure, but only about 15 to 20% of patients have tumors that can be removed at the time of diagnosis. For tumors in the head of the pancreas, the standard operation is the Whipple procedure, which removes the head of the pancreas along with part of the small intestine, the bile duct, and the gallbladder. It is a major operation with significant recovery time, and complications like delayed stomach emptying, infections, and leaking from surgical connections are common.
After a Whipple procedure, many people need to take enzyme supplements with meals for the rest of their lives to compensate for reduced digestive capacity. Some develop diabetes if enough insulin-producing tissue is removed. Nutritional support is a central part of recovery.
For tumors that are borderline resectable, meaning they touch but don’t fully surround nearby blood vessels, chemotherapy or radiation may be given first to shrink the tumor enough to make surgery feasible. When surgery isn’t an option, chemotherapy becomes the primary treatment, aimed at slowing the cancer’s growth and managing symptoms.
Why Pancreatic Cancer Is Hard to Treat
Several features make this cancer particularly challenging. The pancreas is surrounded by major blood vessels, making surgical access difficult. The cancer tends to spread before it causes symptoms, so most patients are diagnosed at advanced stages. And pancreatic tumors are surrounded by dense scar-like tissue that acts as a barrier, making it harder for drugs to penetrate.
About 90% of pancreatic ductal adenocarcinomas carry a specific genetic mutation called KRAS, which drives the cancer’s growth. For decades this mutation was considered “undruggable.” Researchers have now developed compounds that can target one common version of this mutation (KRAS G12D), and early laboratory and animal studies show promise in slowing tumor growth. These drugs remain in early development, but they represent the first real progress against what has long been one of the cancer’s most stubborn molecular targets.