Pancreatic cancer is a serious but relatively rare disease. In most cases, it doesn’t cause symptoms until it has become large or spread to other parts of the body.
- What is pancreatic cancer?
- Understanding your pancreas
- Types of pancreatic cancer
- Causes and risk factors
- How common is pancreatic cancer?
- Next steps
What is pancreatic cancer?
When pancreas cells begin to grow abnormally they can turn into cancer. Cancer cells do not respond to regular cell growth, division and death signals like they are supposed to. They also don’t organize normally. Instead they grow into a tumor, which may break through nearby tissues or spread to other parts of the body.
Understanding your pancreas
Your pancreas is in your abdomen, behind your stomach. It is surrounded by your small intestine, liver and spleen.
Most of your pancreas consists of exocrine cells. These cells produce and secrete enzymes that aid in the breakdown of foods.
- Lipase breaks down fats.
- Protease breaks down proteins.
- Amylase breaks down carbohydrates.
A small portion of your pancreas consists of endocrine cells. These cells produce and secrete hormones, including:
- Gastrin, which triggers release of acid in your stomach
- Insulin, which helps lower the level of sugar in your blood
Types of pancreatic cancer
It is important to know whether a pancreatic tumor started in the exocrine cells or endocrine cells because there are different treatment strategies and prognoses for each type of tumor.
Exocrine pancreatic cancer
The term “pancreatic cancer” is often used to refer to cancer that started in the exocrine cells of the pancreas.
Most pancreatic cancers are exocrine cancers that begin in the ducts that carry pancreas juices and enzymes to the common bile duct, which empties into the first section of the small intestine (duodenum).
The most common of these cancers is adenocarcinoma. Nearly 95 percent of exocrine pancreatic cancers are adenocarcinomas. There are several other exocrine pancreatic cancers, also called nonendocrine pancreatic cancers.
Pancreatic neuroendocrine tumors
Pancreatic cancers that start in the endocrine cells are called pancreatic neuroendocrine tumors (NETs). They are also known as neuroendocrine tumors of the pancreas or islet cell tumors.
NETs can be either malignant (cancer) or benign (not cancer).
Malignant pancreatic NETs are very rare, accounting for about 1 percent of newly diagnosed pancreatic cancers. Some secrete hormones (functional NETs), and others don’t (nonfunctional NETs).
There are several types of NETs, named for the type of endocrine cell where they began. The most common functional NETs are:
- Gastrinoma, which makes large amounts of the hormone gastrin
- Insulinoma, which makes too much of the hormone insulin
Symptoms of pancreatic cancer
Most pancreatic cancers, including nonfunctional pancreatic NETs, do not cause symptoms until they become large or spread to other parts of the body.
Exocrine pancreatic cancer symptoms
Exocrine pancreatic cancer is often advanced by the time it is found.
- One of the most pronounced symptoms is pain in the upper abdomen and back.
- At times the cancer may cause the gallbladder to swell.
- Because 80 percent of pancreatic cancers occur in the head of the pancreas, where they can block the bile duct, they may cause jaundice (yellowing of the skin or whites of the eyes and darkened urine).
- When cancer interferes with food processing, it can cause weight loss, pale and greasy stools, and vomiting and nausea after eating.
Pancreatic NET symptoms
Pancreatic NETs that have spread may cause symptoms such as:
- Enlarged liver, abdominal pain, poor appetite and jaundice if they have spread to the liver
- Breathing problems or coughing if they have spread to the lungs
Functional NETs, which release hormones, may cause symptoms related to the hormone they release, including:
- Gastrinomas — recurring stomach ulcers, diarrhea, weight loss and gastroesophageal reflux
- Insulinomas — low blood sugar and related symptoms (like weakness and confusion); fast heartbeat; if blood sugar gets very low, unconsciousness, coma and seizures
- Glucagonomas — high blood sugar, diabetes, diarrhea, weight loss, nutrition problems and skin rash on the face, stomach or legs
- Somatostatinomas — diarrhea, diabetes, abdominal pain, nausea, poor appetite and jaundice
- Vasoactive intestinal peptide tumors (VIPomas) — diarrhea, digestion problems, high blood sugar and low potassium (which may cause weakness, cramps, numbness, tingling and other symptoms)
- Pancreatic polypeptidomas (PPomas) — abdominal pain, enlarged liver and diarrhea
Diagnosing pancreatic cancer
If you have signs or symptoms that could be from pancreatic cancer, your doctor will start by asking about your medical history and family history and doing a physical exam.
Exocrine pancreatic cancer diagnosis
If your doctor suspects you have exocrine pancreatic cancer, you may have one or more imaging studies, such as:
- Computed tomography (CT) scan — to look for any abnormal growth on your pancreas
- Laparoscopy — inserting a specialized telescope with a camera into your abdomen through small incisions to view your pancreas and surrounding organs
- Magnetic resonance imaging (MRI) — to get a picture of your pancreas ducts if your major blood vessels are compressed or invaded by cancer
- Endoscopic retrograde cholangiopancreatography (ERCP) — threading a flexible tube (endoscope) through your mouth into your small intestine to look at your pancreas, inject dye that helps the area show up better on an X-ray or use a fine needle or brush to take cells for a biopsy (to look at the cells under a microscope and see if they are cancer)
Traditionally, patients with pancreatic cancer have needed exploratory surgery to determine whether their pancreas should be removed. Now doctors often opt for the less invasive imaging procedures described above.
Tests for CA 19-9, a molecule released into the blood by some pancreatic tumor cells, can be useful in tracking the progression of the disease, but it is only 80 percent accurate in diagnosing pancreatic cancer.
Pancreatic NETs diagnosis
To help diagnose pancreatic NETs, you might have a CT scan, MRI or ERCP or one of these imaging studies:
- Somatostatin receptor scintigraphy (Octreoscan) — injecting a hormone-like substance bound to a radioactive substance into your blood so it will travel through your body and attach to proteins on NET cells, making tumors visible on a scan
- Endoscopic ultrasound — threading an endoscope with an ultrasound probe through your mouth into your small intestine, where the probe uses sound waves to create pictures of your pancreas or other internal structures
- Angiography — injecting dye that shows up on X-rays into one of your arteries to detect blood vessels that serve a possible tumor or may be compressed by a tumor
You might also have blood tests to measure hormone levels that can be abnormal with some NETs and to check for chromogranin-A (CgA), a substance that goes up with most pancreatic NETs.
A biopsy is the only way to definitively diagnose pancreatic NETs. Your doctor may take a sample of cells in one of these ways:
- By inserting a thin needle through your abdomen into a suspected tumor to withdraw cells (fine-needle aspiration)
- Surgically, either through small incisions in your abdomen (laparoscopy) or a larger incision (laparotomy), using fine-needle aspiration or a larger needle to take a bigger sample of cells (core needle biopsy)
What causes pancreatic cancer?
Very little is known about the exact cause of pancreatic cancer. Many studies have drawn links between the disease and various types of behaviors and genetic groups.
SCCA’s Gastrointestinal Cancer Prevention Program offers a personalized approach to risk assessment, screening and prevention for people at high risk for pancreatic cancer and other gastrointestinal cancers.
These factors may affect your risk for pancreatic cancer:
- Smoking — Adenocarcinomas are two to three times more common in heavy smokers than in nonsmokers.
- Age — Though pancreatic cancers are sometimes found in young people, most are found in people over 60.
- Sex — Men are more often diagnosed than women.
- Ethnicity —African-Americans, Ashkenazi Jews and Native Hawaiians have the highest rates of pancreatic cancer. Asians and Hispanics have the lowest rates.
- Diet — A diet high in meats and fats has been linked to increased risk.
- Diabetes mellitus — Pancreatic cancer is more common in people with diabetes.
- Environment — Pancreatic cancer is more common in people with prolonged exposure to pesticides, dyes, petrochemicals and other carcinogens.
- Family history — People with a parent or sibling who has had pancreatic cancer are three times more likely to also be diagnosed. A family history of colon cancer or ovarian cancer also increases the risk of pancreatic cancer.
How common is pancreatic cancer?
The American Cancer Society estimates that about 55,000 people in the United States will be diagnosed with pancreatic cancer (either exocrine or endocrine) each year.