The pancreas is an organ that sits behind the stomach. It produces enzymes necessary to digestion, as well as hormones which regulate blood sugar.
About 3% of new cancers diagnosed in the United States are pancreatic cancers. It is marginally more common in men than women. The average age at diagnosis is 70, and almost all pancreatic cancers occur after the age of 45 (about 66% are diagnosed after the age of 65).
Early pancreatic cancers rarely cause symptoms, but as the disease progresses, it may cause:
Jaundice (in most pancreatic cancers this is the first symptom)
Fatigue / physical weakness
Light colored or greasy stools
Itchy skin
Dark urine
Belly or back pain
Weight loss and loss of appetite
Nausea and vomiting
Gallbladder or liver enlargement
Blood clots (including deep being thrombosis and pulmonary embolism)
Diabetes
These symptoms may be caused by any number of health conditions, and should be evaluated by a medical professional.
Pancreatic cancer can originate in the organ’s exocrine (digestive) cells or endocrine (blood sugar regulation) cells. Exocrine cancers are much more common. Various forms of both exocrine and endocrine cancers of the pancreas are characterized by distinct features and biological behaviors:
Pancreatic adenocarcinoma: These cancers, which begin in the ducts of the pancreas, account for 95% of all exocrine cancers of the pancreas.
Ampullary cancer: This cancer forms where the pancreatic duct and bile duct come together to empty into the small intestine, a region known as the ampulla of Vater. While these are not technically pancreatic cancers, they are treated very similarly, and may cause similar symptoms. Because these cancers tend to block the bile duct when they are still small, they are usually found earlier than other pancreatic cancers, and have a better prognosis.
Pancreatic neuroendocrine tumors (NETs): These cancers form in the pancreas’s neuroendocrine cells. Approximately 50% of NETs are considered functioning NETs, which means they produce hormones that cause symptoms. The other half are non-functioning, meaning they often show no symptoms until they have grown quite large.
Rarer forms of pancreatic cancer: Both the exocrine and endocrine cells can develop less-common types of cancer. For exocrine cells, these include adenosquamous carcinomas, squamous cell carcinomas, signet ring cell carcinomas, acinar cell carcinomas, undifferentiated carcinomas, and undifferentiated carcinomas with giant cells. For endocrine cells, these include pancreatic neuroendocrine carcinomas (a faster growing and faster spreading form of NET) and carcinoid tumors, which are more often found in other parts of the digestion system.
There are also both benign and precancerous growths that can form in the pancreas. These are sometimes found due to CT scans, and may or may not require treatment.
Pancreatic cancer survival rates are based on how far the cancer has spread:
Localized: There is no sign the cancer has spread outside the pancreas.
Regional: The cancer has spread to nearby structures or lymph nodes
Distant: The cancer has spread to distant parts of the body.
The 5-year survival rate for each stage is shown below:
Incidence
Below is the overall incidence of pancreatic cancer by age group:
Risk Factors
There are several confirmed risk factors that contribute to an individual’s risk for pancreatic cancer:
Smoking & secondhand smoke exposure: Smoking and secondhand smoke increase your risk of many cancers, and double your risk for pancreatic cancer – about 25% of all pancreatic cancers are thought to be caused by smoking. Tobacco smoke contains numerous carcinogens that can lead to genetic mutations and uncontrolled cell growth, ultimately resulting in cancer. Quitting smoking at any age can significantly reduce the risk of cancer and other smoking-related diseases. The body begins to repair itself almost immediately after quitting, with the risk of cancer decreasing over time. Even individuals who have smoked for many years can benefit from quitting, as the risk decreases with each year of abstinence.
Alcohol use: Alcohol has been shown to increase the risk of pancreatic cancer, particularly in individuals who drink heavily.
Height: Research has consistently shown a correlation between height and an increased risk of several types of cancer, including pancreatic. Taller individuals tend to have higher levels of IGF-1, a hormone that plays a critical role in growth and development. IGF-1 can promote cell proliferation and inhibit cell death, which may contribute to the development and progression of cancer. Taller individuals also have more cells in their body simply due to their size, which leads to a higher probability of cells mutating.
Occupation: Exposure to chemicals used in the dry cleaning and metal working industries has been shown to increase rates of pancreatic cancer.
Health conditions: some text
Chronic pancreatitis: This long-term inflammation of the pancreas is often the result of excessive alcohol consumption or of cigarette smoking.
Diabetes: Diabetes, particularly type 2 diabetes, correlates with increased risk of pancreatic cancer, though the mechanisms behind this are not well understood.
Cystic fibrosis: Complications that can arise with cystic fibrosis, particularly as individuals with the disease live longer, may increase the risk for pancreatic cancer.
Hepatitis B infection: Some studies indicate this infection increases the risk of pancreatic cancer, though more research is needed.
H. pylori infection: Infection with the ulcer-causing bacteria Helicobacter pylori has been shown to increase the risk of pancreatic cancer, though the underlying driver of this linkage is still under investigation.
Genetic conditions: As many as 10% of pancreatic cancers are likely caused by inherited genetic conditions. Conditions that increase one’s risk include: some text
Hereditary breast and ovarian cancer syndrome (HBOC, caused by mutations to the BRCA1 or BRCA2 gene)
Hereditary breast cancer (caused by mutations to the PALB2 gene)
Family history: A family history of pancreatic cancer, even without a known hereditary cancer syndrome, increases one’s risk of developing pancreatic cancer.
Periodontitis: Periodontal disease is characterized by chronic inflammation of the gums and surrounding tissues, resulting from bacterial infection and immune response. Chronic inflammation is a known risk factor for cancer, as it can promote cellular changes, DNA damage, and abnormal cell proliferation. Systemic inflammation associated with periodontal bone loss may contribute to an increased risk of kidney and pancreatic cancers.
Blood Types A, B and AB: Individuals with blood type A, B, or AB all have an increased risk of pancreatic cancer relative to population average.
Protective Factors
Several factors have been shown to have protective effects against pancreatic cancer:
Maintaining a healthy weight: Numerous studies have linked higher BMI to increased risk of various types of cancer, including pancreatic cancer. Excess body fat can lead to higher levels of estrogen and insulin, as well as increased production of insulin-like growth factors. Higher BMI is also associated with chronic low-level inflammation, which can cause DNA damage over time and contribute to the development of cancer. Individuals with a BMI over 30 have a 20% higher risk of developing pancreatic cancer. Maintaining a healthy weight helps you to avoid this increased risk.
Physical activity: Regular exercise can reduce your risk of several types of cancer through a combination of physiological, hormonal, and immunological changes. It can reduce inflammation, improve immune function, improve hormonal regulation, and lower insulin levels. The American Cancer Society recommends engaging in at least 150 minutes of moderate activity or 75 minutes of vigorous activity each week. Furthermore, data indicates that individuals can see significant incremental benefit with additional exercise.
Diet: Diets low in red and processed meats, saturated fats, and added sugars may have a protective effect against pancreatic cancer. Increased fruit and vegetable consumption has also been shown to have a protective effect, likely due to the many antioxidants these foods contain, which help neutralize free radicals and reduce inflammation in the body.
Blood type O: Compared to all other blood types, those with blood type O have a reduced risk of pancreatic cancer.
Screening
Early detection of pancreatic cancer has a dramatic impact on prognosis. The 5-year survival rate for localized cancer is around 44%, but drops to just 3.1% once the cancer has spread to distant parts of the body.
Depending on your age and risk factors, the optimal pancreatic cancer screening will vary:
Medical history / physical exam: A thorough medical history and physical examination is often the best first test for possible pancreatic cancer. Knowing your family history, any recent changes you’re experiencing, and carefully palpating your abdomen (which may detect swelling in the gallbladder or liver, which may occur with pancreatic cancer) can help your doctor determine whether further testing is necessary.
Endoscopic ultrasound (EUS) and MRI cholangiopancreatography (MRCP): These imaging tests can be used to detect pancreatic cancer in individuals at high risk for the disease due to inherited genetic conditions or family history. These tests are not currently used to screen the general public.
CT scan: While not routinely used as a screening tool, a regional CT scan can help identify pancreatic cancers, and show whether they have spread.
Blood and tumor marker tests: Blood tests can show whether jaundice is caused by problems in the liver itself, or by blockage of the bile duct, a feature that could indicate pancreatic cancer (or a more benign diagnosis, such as a gallstone). Blood tests that specifically look for tumor markers can also be useful in discovering pancreatic cancer. For pancreatic cancer, the relevant markers are CA 19-9 and carcinoembryonic antigen (CEA). It’s important to note that these markers may indicate other health issues, or may not be high in individuals with pancreatic cancer.
Genetic testing: Genetic testing focused on the conditions known to cause pancreatic cancer can help give you a better idea of your overall risk, and may affect your treatment plan if pancreatic cancer is discovered. Genetic testing is particularly useful for individuals with a family history of pancreatic cancer.
Liquid biopsy: Liquid biopsy is an investigational cancer-detection technique which looks for DNA fragments in the blood to determine whether cancer is present. Though still in its infancy, this technology is promising, particularly in screening for hard-to-detect cancers or cancers whose symptoms are minimal or tend to appear only after they’ve spread. Exocrine pancreatic cancer is one of many cancers which can be screened for via this method.