Pancreatic cancer is abnormal, uncontrolled growth of cells in the pancreas.
‘Pancreatic cancer’ is a broad term for any type of cancer that begins within the pancreas. There are many different types of pancreatic cancer. Each type requires a different treatment and has a different outlook for survival (prognosis). The most common type of pancreatic cancer is pancreatic adenocarcinoma.
The term ‘pancreatic cancer’ is not used for benign tumours (abnormal growths that are not invasive), or for abnormal cell growth that is not yet cancer.
The pancreas is a gland in the abdomen, slightly behind your stomach and in front of your spine. It pancreas is about 25 cm long and is shaped like a tadpole; it is thick and rounded at one end and long and thin at the other end.
The pancreas has two main functions:
- It produces digestive enzymes to help break down the food you have eaten. Ducts (tubes) within the pancreas carry the pancreatic juices to the duodenum (the first part of your small intestine).
- It produces hormones (insulin and glucagon). These hormones balance the glucose levels in your blood and body cells.
Because the pancreas has different parts with separate functions, there are many different types of cells that can become cancerous (multiply in an abnormal and uncontrolled way).
Types of pancreatic cancer
Pancreatic cancers are often divided into two main types:
- neuroendocrine (or endocrine) – uncommon
- non-endocrine (or exocrine) – common.
Neuroendocrine tumours of the pancreas
Neuroendocrine tumours of the pancreas (also called islet cell tumours) begin in the part of the pancreas that produces hormones. They include gastrinomas, insulinomas, glucagonomas, and some other types. Insulinomas are usually not cancer.
Non-endocrine pancreatic cancer
Non-endocrine pancreatic cancer means any cancer that begin in any other part of the pancreas. These are by far the most common types of pancreatic cancers. About 95% of all pancreatic cancers are adenocarcinomas. About four out of five people with pancreatic cancer have ductal adenocarcinomas – cancers that start in the tubes that transport digestive juices to the bowel.
Other, less common, non-endocrine pancreatic cancers include acinar cell carcinoma, acinar cell cystadenocarcinoma, intraductal papillary mucinous neoplasm with invasive carcinoma, mixed acinar-ductal carcinoma, mixed acinar-neuroendocrine carcinoma, mixed acinar-neuroendocrine-ductal carcinoma, mucinous cystic neoplasm with invasive carcinoma, pancreatoblastoma, serous cystadenocarcinoma and solid-pseudopapillary carcinoma.
Symptoms of pancreatic cancer
Most pancreatic cancers do not any cause symptoms until they grow big enough to interfere with other organs.
Symptoms can include:
- pain in the upper abdomen
- loss of appetite
- being unusually tired
- nausea
- vomiting
- losing weight for no obvious reason
- either diarrhoea or constipation
- pale stools (bowel motions, faeces)
- jaundice (yellow colour in the white parts of the eye or yellow skin, dark-coloured urine)
- back pain that comes and goes, or does not get better over time.
Some people with pancreatic cancer also develop diabetes.
Neuroendocrine tumours of the pancreas can cause other symptoms if they produce excessive amounts of hormones, even if they are not cancers. These can include skin rash or symptoms of low blood glucose (hypoglycaemia), such as sweating, rapid or pounding heartbeat, weakness, blurred vision or confusion.
What causes pancreatic cancer?
Like other cancers, pancreatic cancer occurs when there are abnormal changes in the DNA within the body’s cells. Exactly why this happens is not yet known.
Only about one in 10 pancreatic cancers is caused by genetic abnormalities inherited from your parents. The risk may be higher in families with ovarian cancer, colon cancer, hereditary pancreatitis syndrome, or hereditary atypical multiple mole melanoma syndrome.
The main factors that could increase your risk of pancreatic cancer are:
- tobacco smoking – smoking cigarettes is the main risk factor, but other people’s smoke could also increase your risk
- obesity (having a BMI higher than 30)
- eating a lot of red meat, saturated fats and processed foods
- not eating enough fruit and vegetables
- drinking too much alcohol
- Helicobacter pylori infection of the stomach, which causes peptic ulcers (ulcers in the stomach or duodenum).
Other possible risk factors include:
- chronic pancreatitis (long-term inflammation of the pancreas). This condition is most often caused by excessive use of alcohol
- having type 1 diabetes or type 2 diabetes
- having part or all of your stomach removed (gastrectomy)
- being exposed to some industrial chemicals, such as chlorinated hydrocarbons, compounds that contain nickel, compounds that contain chromium, and silica dust.
Men have a higher risk of pancreatic cancer than women. Your risk of pancreatic cancer also increases with age. It mainly occurs in people older than 65 years.
People who eat a lot of fruits and folate may have a lower risk of pancreatic cancer. Folate is found in leafy green vegetables, some fruits (e.g. oranges and bananas), and legumes (e.g. chickpeas, beans and lentils).
How common is pancreatic cancer?
In Australia, pancreatic cancer is one of the 10 most common types of cancer.
Each year, about 3100 Australians are diagnosed with pancreatic cancer, including about 1600 men and 1500 women. At any time, more than 2000 people in Australia have pancreatic cancer. The rate of new cases of pancreatic cancer diagnosed each year in Australia has increased slightly since the early 1980s.
More men than women develop pancreatic cancer. The chance of being diagnosed with pancreatic cancer before age 85 is estimated at one in 72 for Australian women and one in 59 for Australian men. Of all the new cases of cancer diagnosed in Australia each year, about one in 42 (2.4%) cases are pancreatic cancer.
Over 2800 Australians die from pancreatic cancer each year. Of all the Australians who die of cancer in one year, about one in 20 has pancreatic cancer.
Diagnosis
Pancreatic cancer is very hard to diagnose early. For most people, it is only diagnosed after several visits to their GP, tests, and referral to a specialist.
There is no simple test that you can have, and there is no national screening program for pancreatic cancer in Australia.
If your doctor suspects that you could have pancreatic cancer, you will have a physical examination, blood tests and imaging studies.
Imaging studies are tests to take pictures of your pancreas and nearby organs. They can include ultrasound, computed tomography (CT scan), magnetic resonance imaging (MRI scan) and positron emission tomography (PET scan).
In Australia, a CT of your abdomen is usually recommended as the first imaging test if you could have pancreatic cancer. CT scanners use X-rays to make detailed pictures of slices of your body. The computer can put together these slices to make a 3-dimensional (3D) picture of your pancreas and other organs.
If scans show that surgery may be possible to remove pancreatic cancer, you may need more scans and tests. These could include:
- PET scan – a special camera and computer is used to take pictures of your organs using a low dose of radiation. First, a radioactive liquid is injected into your vein. Then you lie on a bed inside the scanning machine.
- endoscopic ultrasound – an endoscope (stomach tube) is used to place an ultrasound probe in your abdomen. Ultrasounds use sound waves to take detailed pictures of your internal organs.
- endoscopic retrograde cholangiopancreatography (ERCP) – an endoscope is passed into the first part of the small intestine (duodenum) to take X-rays of the pancreatic and bile ducts.
- laparoscopy – a tiny camera is inserted through a cut in the wall of the abdomen.
- biopsy – a small sample of tissue is removed for examination under a microscope. A biopsy can be taken using an ERCP or a laparoscope.
Complications
Pancreatic cancer can cause blockage of your bile duct, the tube that delivers bile (a type of digestive juice) from the liver and the gall bladder to your small intestine. Blockage of the small intestine can also be caused by pancreatic cancer.
Diabetes develops in up to one in 5 people with pancreatic cancer.
Neuroendocrine tumours of the pancreas can make excessive amounts of hormones. Tumours of the cells that make insulin (insulomas) can produce abnormally high levels of insulin, which causes low blood glucose. Glucagonomas can cause a skin rash.
How is pancreatic cancer treated?
Surgery
Surgery to remove some or all of the cancer is only possible in a small percentage of people with pancreatic cancer.
If your cancer is at the head (the thick end) of the pancreas, your surgeon may consider performing a ‘Whipple procedure’ (also called pancreaticoduodenectomy). This is a complex operation that involves removing part or all of the pancreas, the gallbladder, part of the bile duct, part of the stomach, parts of the small intestine, and nearby lymph nodes. If the cancer is only in the tail (thin end) of the pancreas, a distal pancreatectomy may be possible. This is slightly less complex than a Whipple procedure, but is still a major operation.
Sometimes chemotherapy, radiotherapy, or a combination of both, is used before surgery to shrink the cancer.
Chemotherapy and radiotherapy
Your doctor might consider chemotherapy (drug treatment to kill cancer cells) if you are fairly well and have a good chance of survival.
Various treatments for pancreatic cancer are available in Australia. These include paclitaxel (e.g. Albraxane), gemcitabine, and combinations that contain fluorouracil. The particular drug or combination that is best for you depends on how far your tumour has spread and the results of your blood tests. Your treatment is usually monitored with scans.
Radiotherapy (the use of X-rays to kill cancer cells) can also be combined with chemotherapy (chemoradiation).
Chemotherapy is not usually suitable for people who are already unwell and have a short life expectancy.
Other treatments
Most people with pancreatic cancer need treatment to control pain. This can involve medicines and radiation. In Australia, specialists sometimes prescribe morphine if pain is due to nerve damage caused by the cancer.
For people with pancreatic cancer who are experiencing severe pain and are near the end of their life, cancer specialists sometimes suggest a nerve block to stop the pain. A nerve block involves injecting drugs (anaesthetic and drugs that kill nerves) directly into the nerves in your abdomen. Nerve blocks can control pain in about four out of five people with severe pain from pancreatic cancer.
If your bile duct is blocked by the cancer, your surgeon may be able to place a stent (a small tube) in your bile duct to keep it open. This can be done through an endoscope (stomach tube).
Stents can also be used to keep your small intestine open if it has been blocked by pressure from the cancer. This type of surgery can also be done through an endoscope, to avoid a bigger operation.
Researchers are constantly looking for better treatments for people pancreatic cancer. You may be invited to take part in a clinical trial to test a new treatment.
Prognosis
Your chance of surviving pancreatic cancer depends on many different factors. These include the type of cancer, how soon your cancer is diagnosed, your age, and your general health.
In general, pancreatic cancer has a low survival rate. This is mainly because it is usually not diagnosed until the cancer has spread too far to be curable.
In Australia, survival rates are improving for people with pancreatic cancer. Compared with the 1980s, the percentage of people who are still alive 5 years after being diagnosed with pancreatic cancer has more than doubled. Today, about 1 in 14 people (7%) survive 5 years or more.
