Pancreatic Cancer Overview
Information in this section was drawn from the expertise of gastroenterologists Dr. David Armstrong, Dr. Francis Tse, and oncologist and Dr. Rachel Goodwin. Watch this information in video form through our #CDHFTalks.
What is Pancreatic Cancer?
- What are the types of pancreatic cancer?
Pancreatic cancer covers a number of different cancers that that arise from different parts of the pancreas. However, the most common type of pancreatic cancer is what is called Pancreatic Ductal Adencarcinoma (PDAC), which accounts for about 90 per cent of all pancreatic cancers. There are other types of pancreatic cancer arising from other cell types. Tumours such as acinar carcinoma, pancreaticoblastoma and neuroendocrine tumours or NETS that produce hormones such as gastrin. It’s important to know what type of pancreatic cancer someone has so that their oncologist and their other health care providers can decide how best to treat the cancer.
Each year, about 6,000 Canadians are diagnosed with pancreatic cancer and of those, about 5,300 will die each year. There are slightly more men affected than women and the data in Canada are very similar to those in the United States where about 60.000 people are diagnosed with pancreatic cancer every year. In the United States, it’s about the 10th or 11th most common cancer but it is actually the 3rd leading cause of cancer mortality
And the reason for this is that pancreatic cancer is usually diagnosed late. It often does not produce any symptoms until it has spread through the pancreas and, in fact, in about 50% of people, the cancer has spread beyond the pancreas at the time of diagnosis. The result is that the five year survival rate are only around 10 per cent for pancreatic cancer.
In deciding how best to treat pancreatic cancer, it’s important to know what the pancreas actually is and what it does, because this is important to ensure that the proper treatment and nutritional support is provided.
The pancreas is actually quite a small organ. It’s located in the upper part of the abdomen towards the back, and it’s only about six inches long, weighing about three or four ounces. It is, however, a very important organ and it has two major functions. It has what’s called an endocrine function, that is it secretes hormones such as insulin and glucagon that control the body’s blood sugar levels and carbohydrate metabolism, and it also has what is called an exocrine function, that is, it secretes digestive enzymes as well as water and bicarbonate that are produced by little clusters of cells, what are called sacs or an acinis, a little sac. And these acini produce enzymes and the ducts which then collect the secretions also produce water and bicarbonate that are then transported along the pancreatic duct, joining the bile duct before they’re released into the upper part of the small intestine or duodenum where they mix with food and help with digestion.
The result of this is that any disease, and particularly pancreatic cancer, that affects the pancreas, can affect digestion and it can therefore affect people’s nutritional status.
What are the Causes of Pancreatic Cancer?
- Are there lifestyle factors linked to pancreatic cancer?
Unfortunately, we really don’t know the specific causes of pancreatic cancer, but we do know that there are some lifestyle factors and also some hereditary factors that are associated with an increased risk of pancreatic cancer. The lifestyle factors that are associated with pancreatic cancer include tobacco, particularly cigarette smoking, as well as increased alcohol consumption. And one of the results of increased alcohol consumption can be chronic inflammation or chronic pancreatitis that is also a risk factor for pancreatic cancer. In addition, people who are obese or overweight, particularly with a body mass index or BMI of over 30 have an increased risk of pancreatic cancer as do some dietary factors including high fat diets, saturated fats and processed meats.
Hereditary causes account for about five to ten per cent of pancreatic cancers. There are a number of syndromes, genetic syndromes or hereditary syndromes associated with pancreatic cancer. The most common ones are hereditary breast and ovary cancer syndrome and another called Ataxia-telangiectasia syndrome. These, together, probably account for about 80 to 90 per cent of the hereditary factors associated with pancreatic cancer.
What are the Symptoms of Pancreatic Cancer?
- What symptoms would cause someone to suspect it?
In the early stages, pancreatic cancer is extremely difficult to diagnose because there are not many early warning signs or symptoms. But as the cancer grows and starts to spread to other parts of the body, people may develop non-specific symptoms. And these symptoms may include: pain in the upper abdomen or back, jaundice, which is yellow discolouration of the skin and eyes, dark urine, clay coloured stools, itchy skin, loss of appetite, nausea/vomiting, change in bowel habits, new onset diabetes and unintentional weight loss.
There are other signs and symptoms of pancreatic cancer as well, but it’s important to remember many of these symptoms can be caused by many other conditions, such as ulcer in the stomach, gallstone disease and liver disease. And so, they’re not very specific for pancreatic cancer. And the symptoms can also be very variable, depending on the size and location of the cancer in the pancreas. With that in mind, it is still important to see a doctor right away if you have any of these symptoms.
But not all pancreatic cancer patients will experience jaundice. Whether a patient will develop jaundice or not depends on the size and location of the tumour. Cancers that start in the head of the pancreas are near the common bile duct and these cancers can press on the bile duct and cause jaundice while they’re still fairly small, which can sometimes lead to these cancers being found at an early stage. On the other hand, cancers that start in the body or tail of the pancreas, don’t press a lot until they have spread throughout the pancreas. By this time, the cancer has already spread beyond the pancreas. And when pancreatic cancer spreads, it often goes to the liver. This can also cause jaundice.
And third, bile duct blockage by the cancer can cause bile to back up into the blood. As a result, people may experience nausea, vomiting, loss of appetite and weight loss. And finally, some patients may develop diabetes because the cancer destroys the insulin making cells of the pancreas. Insulin is a hormone that controls how the body uses and stores blood sugar. With too little insulin, the body cannot move the blood sugar from the blood into the cells to use as energy and when this happens, the body starts burning fat and muscle for energy, causing a reduction in body weight.
What are the Tests used to Find Pancreatic Cancer?
- Who should be tested for pancreatic cancer?
If your doctor suspects pancreatic cancer based on your signs and symptoms, he or she may order some tests to confirm the diagnosis. And these may include blood tests, imaging scans, endoscopic tests and tissue biopsy. But for people without symptoms, screening for pancreatic cancer is currently not recommended. In people with certain inherited genetic syndromes or history of familial pancreatic cancer, they are considered to be at higher risk for pancreatic cancer and they may be eligible for certain screening tests such as MRI or endoscopic ultrasound.
There are currently no accurate validated blood tests for the diagnosis for pancreatic cancer. Most of the time, pancreatic cancer does not show up on blood tests. And the blood tests that you would normally do at your family doctor’s office, they look for relatively non-specific things, like liver function tests. And certain, pancreatic cancer can cause some abnormalities in liver function tests, and this can happen because a tumour may have spread to the liver or, in some cases, it blocks up the drainage of the bile duct. However, many conditions can cause similar abnormalities and most of the time, that doesn’t mean a pancreatic cancer is present.
But once a pancreatic cancer is diagnosed by imaging, your doctor may order specific blood tests for tumour markers that are shed by pancreatic cancer cells. And these tumour markers are CA 19-9 or CEA level, which stands for Carcinoembryonic Antigen. Now, none of these tumour markers is accurate enough to tell for sure if someone has pancreatic cancer because some people with pancreatic cancer do not have elevate levels of these tumour markers. But some people who don’t have pancreatic cancer might have high levels of these tumour markers for other reasons. And still, then tumour markers can sometimes be very helpful, along with other tests in figuring out if someone has pancreatic cancer or not.
And in people who are already known to have pancreatic cancer or have high tumour markers to begin with, these levels can be measured over time to help determine how well the treatment is working. If all of the cancer has been removed, these tests can also be done to look for signs the cancer may be coming back.
If you have unexplained abdominal pain or jaundice, abdominal ultrasound might be one of the first imaging tests done because ultrasound is easy to do. It doesn’t expose you to radiation. Ultrasound can be very helpful in ruling out gall bladder or liver conditions that can cause similar symptoms as pancreatic cancer. But if you have signs and symptoms that are more likely to be caused by pancreatic cancer, a CT scan is often more useful.
So, a CT scan uses x-ray to make detailed cross-sectional images of the body. And CT scans are often used to diagnose pancreatic cancer because they can show the pancreas very clearly. They can also show if the cancer has spread to other organs and lymph nodes. A CT scan is also very helpful in determining if surgery might be a good treatment option.
If a CT scan is inconclusive or if your doctor wants better images of the pancreas, an MRI can be used. Unlike CT, MRI do not use radiation. Instead, MRI uses magnetic fields and radio waves to make detailed images of the pancreas. So, tumours that are not visible on CT scans, sometimes would appear on MRI scan.
Endoscopic ultrasound or EUS in short, is one of the most useful imaging studies for diagnosing and staging pancreatic cancer. An EUS is a type of endoscopic procedure. This involves insertion of a flexible tube into the mouth, down the stomach and into the first part of the small intestine. At the tip of the tube is a small ultrasound probe that transmits sound waves. The sound waves then bounce off the surrounding structures such as pancreas, bile duct and liver and are then captured by the probe and converted to ultrasound images. Because the pancreas sits right next to the stomach and small intestine, EUS allows the physician get very detailed images of the pancreas.
Many studies have shown that EUS is better than abdominal ultrasound, CT or MRI in finding small pancreatic tumours that are less than three centimetres in size, but the biggest advantages of EUS is that unlike CT or MRI, biopsies of the tumour can be easily and safely obtained at the time of the procedure. These biopsies, often referred to as fine needle biopsy or fine needle aspiration can allow your doctors to make a definitive diagnosis of the cancer. During EUS, we pass a small needle down the scope directly into the tumour to take a biopsy. Because this is done under ultrasound guidance, EUS is considered a safe procedure with low complication rates.
There is another endoscopic procedure called ERCP, which stands for endoscopic retrograde cholangiopancreatography. This can also be done to diagnose pancreatic cancer, however this test is not recommended solely as a diagnostic test because it carries a higher risk for serious complications than other imaging tests. ERCP is often used as a therapeutic procedure to relieve blockage of the bile duct caused by pancreatic cancer. During ERCP, a tube is passed down the mouth, into the small intestine where a small catheter is inserted into the bile ducts. Dye is then injected and x-rays are taken. The x-ray will show where the blockage is in the bile duct. A small sample can be taken from the bile duct to confirm the diagnosis. A stent, which is a small tube, can also be placed in the bile duct to relieve the blockage. Now, as I said, because of the potential for serious complications, ERCP should be reserved for therapeutic indications.
What Treatments can be used for Pancreatic Cancer?
- Can surgery be used to remove it?
Yes, pancreatic cancer is surgically resectable. In general, about 15 to 20 per cent of patients are found with early cancers that can go on to surgery. These cancers are usually smaller and not growing into any major blood vessels. And in general, they tend to be Stage 1 and Stage 2 cancers.
What is the Role of Diet and Nutrition in Treating Pancreatic Cancer?
- Why does pancreatic cancer cause weight loss and malnutrition?
Diet and nutrition are very important for patients with pancreatic cancer. Patients with pancreatic cancer are particularly at risk of impaired digestion and nutrition because of damage to the pancreas which then leads to inadequate intake of calories, proteins, vitamins and trace minerals, all of which are essential to maintain general health and also to help cope with and recover from cancer treatment and surgery.
However, it’s also important to remember that the pancreas and the nearby intestinal gut are really important for digestion and nutrition. Pancreatic cancer and often the surgical treatment lead to the loss of pancreatic tissues which then reduces the secretion of the pancreatic enzymes and the fluid, including bicarbonate that are needed to help digest food and absorb it. And it can, if much of the pancreas is affected, also lead to conditions such as diabetes which affects the endocrine part of the pancreatic function.
In addition, as the cancer grows and spreads, it can also affect nearby organs, including the liver, the bile ducts as well as the intestine itself. And all of these can then lead to weight loss and malnutrition. While as for everybody, it’s important to have a healthy diet but it’s particularly important if there’s a risk of pancreatic cancer to make sure that the diet is healthy and that we avoid some of the dietary risk factors that we talked about before.
So, a healthy diet before diagnosis will help reduce the risk of pancreatic cancer but it will also ensure that the body is healthy and has good nutrition to deal with the pancreatic cancer when it’s been diagnosed. And the things that we need to do for our diet are to reduce alcohol intake, to try and avoid overweight or metabolic syndrome, to reduce high fat diets and reduce the amount of saturated fats in the diet that are found in red meat, whole milk dairy foods, coconut oil and many commercially produced foods, and also to reduce the use of processed foods and processed meats.
It’s particularly important in patients with pancreatic cancer to replace the digestive enzymes that are lost when the pancreas is damaged. Pancreatic enzyme replacement therapy is generally given as what are called enteric coated pancreatic enzymes. These are enzyme preparations that have a special coating that protects them against acid in the stomach and these enzymes can therefore be released in the duodenum where the enzymes that they contain, the lipase to digest fat, the amylase to digest carbohydrates and the proteases to digest proteins are released and mixed with the food to promote absorption and promote digestion.
Pancreatic enzyme replacement therapy should be taken with every snack and meal and it’s generally recognized by many of the specialty groups, including the United Kingdom NICE Guidelines group, for example, that pancreatic enzyme replacement therapy should be provided before and after the pancreatic treatment and pancreatic surgery.
Nutrition treatments remain really important, even after the pancreatic cancer has been treated whether or not the treatment has been successful. And they’re really important to aid recovery and to maintain health after the treatment has been completed. The nutrition supplements that are needed after pancreatic cancer treatments include the pancreatic enzyme replacement therapy or PERT. These are the enteric coated capsules that contain digestive enzymes. And these should be taken with all food, regardless of whether it is a snack or a full meal. Generally to start, we recommend that people take one to three capsules with a snack and three to five capsules with a meal. These capsules should be taken mixed with the food during the meal so that the enzymes are mixed with the food and have an opportunity to improve digestion and improve absorption.
Good nutritional treatment after pancreatic therapy for cancer also includes ensuring an adequate supply of macronutrients, that is carbohydrates, fats and proteins, if necessary with supplements and above all, helped by a registered dietician who can provide specific advice regarding the types of foods and supplements that are needed.
And so, most patients who have had treatments for pancreatic cancer will need not just the macronutrients but also the micronutrients, the vitamins and minerals that can become deficient after treatment for pancreatic cancer. These include fat soluble vitamins – Vitamin A, Vitamin D, Vitamin E and Vitamin K – as well as Vitamin B12 that’s important for nerve health and to help with blood production and prevent anemia. And in addition, vitamins and trace elements such as iron and zinc supplements.