Risk factors and causes of pancreatic cancer
Pancreatic cancer is not a common type of cancer and affects 7000 people in the UK each year. Although the cause of pancreatic cancer is unknown, research into this is ongoing all the time. Like other cancers, cancer of the pancreas isn't infectious and can't be passed on to other people.
There are a number of factors that can increase your risk of developing pancreatic cancer. These are:
Pancreatic cancer occurs mainly in people aged between 60 and 80 and is rare below the age of 50. About 6 in10 are diagnosed in people over 70. Some of the rarer types, such as neuroendocrine and papillary cancer (see types), may affect people in their 20s and 30s.
People who smoke are more at risk of developing cancer of the pancreas. Up to a third of all pancreatic cancers may be linked to smoking. People who chew tobacco are also at an increased risk.
Inflammation of the pancreas
People who have chronic pancreatitis – where the pancreas becomes inflamed – are more likely to develop pancreatic cancer. One of the main causes of chronic pancreatitis is drinking large amounts of alcohol over long periods of time. However, other types of pancreatitis are more likely to cause cancer (see section below on inherited faulty genes).
A diet that contains large amounts of fat, sugar, red or processed meat may increase your risk of developing pancreatic cancer. Your risk may also be increased if you don't eat many fresh fruit and vegetables.
There may be a small increase in the risk of developing cancer of the pancreas if you have diabetes. However diabetes is very common and the vast majority of people with it won't develop pancreatic cancer.
Inherited faulty genes
Most cancers of the pancreas are not caused by an inherited faulty gene, and so members of your family are very unlikely to be at an increased risk of pancreatic cancer because you have it.
Some people who have the faulty breast cancer genes BRCA1 or BRCA2, or the bowel conditions FAP (familial adenomatous polyposis) or HNPCC (hereditary non-polyposis colorectal cancer), have a higher risk of developing pancreatic cancer.
There is a rare inherited condition called hereditary pancreatitis, where family members develop pancreatitis because of a faulty gene. People with this condition have an increased risk of developing pancreatic cancer.
Members of families with a tendency to have large numbers of unusual moles (Familial Atypical Multiple Mole Melanoma – FAMMM), also have an increased risk of cancer of the pancreas.
The genetic changes which cause these cases of pancreatic cancer have not yet been found, and so currently there is no genetic test available for pancreatic cancer.
How common is the Pancreatic Cancer in India?
Pancreatic cancer is one of the rare cancers diagnosed in India. The incidence (newly diagnosed cases of Cancer in a year) of Pancreatic cancer for men and women from the Indian subcontinent is about 1 person per 1,00,000 population1.
In India, between the years 2001-2003, across five urban centers - Mumbai, Delhi, Chennai, Bhopal and Bangalore, – and one rural center - Barshi, a total of 728 cases of Pancreatic cancer were registered (1.65% of all cancers) for males across all age groups; while 466 cases of Pancreatic cancer were registered (1.05% of all cancers) for females across all age groups. Considering all men, women and children with all types of cancers together, a grand total of 1,194 cases of Pancreatic cancer (1.35% of all
cancers) were registered at the six centers mentioned above, between the year 2001- 20032.
The TATA Memorial Hospital (T.M.H.) in Mumbai, India registered a grand-total of 19,127 cases of all types of cancer patients in the year 2006 for men, women and children combined, out of which 133 (0.7% of the total cases) were diagnosed with the Pancreatic cancer. Out of the total 133 patients diagnosed with Pancreatic cancer, mentioned above at the T.M.H., 90 (68%) were males and 43 (32%) were females3.
Types of pancreatic cancer
Cancers of the pancreas are divided into groups according to their position within the pancreas and the type of cell that the cancer has started from.
Between 7 and 8 out of 10 of all pancreatic cancers occur in the head of the pancreas (see diagram of the pancreas).
Nearly all pancreatic cancers start from the cells in the inner lining of the pancreatic ducts. These are the channels through which the digestive juices produced by the pancreas flow out into the small bowel. This type of cancer is called adenocarcinoma.
There are other very rare tumours that can affect the pancreas. These include:
a group of conditions called neuroendocrine tumours, which produce hormones
a type of lymphoma – a cancer arising from lymphatic tissue in the pancreas
pancreatic sarcoma, which develops in the tissue that holds together the cells of the pancreas.
Symptoms and Diagnosis
Symptoms of pancreatic cancer
Pancreatic cancer may not cause any symptoms for a long time, and symptoms may be vague to begin with. The most common symptoms caused by cancer of the pancreas are described below. Some people may have only one of these symptoms.
This often begins with discomfort or pain in the upper abdomen, which sometimes spreads to the back. In the beginning the pain may come and go, but later on it can be more persistent. In some people the pain is worse while lying down and it's relieved by sitting up or bending forward
It's common for people with pancreatic cancer to have some weight loss and loss of appetite.
This is yellowing of the skin and the whites of the eyes, itchy skin, dark yellow urine, and pale bowel motions. It can be caused by different illnesses including cancer of the pancreas. Jaundice can occur if the cancer develops in the head of the pancreas, and blocks the bile duct that carries bile from the liver to the intestine. The resulting build-up of bile in the body causes the symptoms mentioned above.
Other symptoms include:
bloating after meals
feeling extremely tired.
Remember, most pain in the abdomen is not caused by cancer of the pancreas. However, you can arrange to see your doctor if you are worried.
How pancreatic cancer is diagnosed
Usually people begin by seeing their GP when they develop symptoms. It can be difficult for a GP to diagnose pancreatic cancer as the symptoms may be vague and can be caused by other conditions. However, your GP will normally look at your eyes and the colour of your skin to detect any jaundice, test your urine for bile and take a blood sample if needed. Your doctor may also examine your abdomen to feel for any swelling in the area of the liver. After this, further tests or x-rays may be arranged.
Your GP will refer you to hospital for these tests and for specialist advice and treatment.
At the hospital, the specialist will ask you about your general health and any previous medical problems, before examining you. You may have a blood test and a chest x-ray to check your general health.
Further tests for pancreatic cancer
To help make the diagnosis, you'll probably have a number of tests. After a diagnosis is made, more tests may be needed to find out about the size and position of the cancer, and whether it has spread to other parts of the body. The results will help your doctor to decide on the best treatment for you.
While tests are useful, no one test can tell the whole story. Even the most modern scans can't always pick up tiny areas of cancer. Occasionally, other medical conditions can cause similar results, making it difficult to decide what is and is not cancer. Doctors often have to piece together information from different tests and examinations, along with your symptoms and medical history, and then put all this information in context.
Usually, only tests that give the most helpful information about the illness are used. The following tests are often used to diagnose cancer of the pancreas:
EUS (endoscopic ultrasound)
Waiting for your test results
Many cancers of the pancreas produce a substance called CA 19 ¬9, which can be measured in the blood. CA 19-9 is known as a tumour marker. Measuring the level of CA 19-9 in the blood can help to diagnose a cancer of the pancreas, and also to see how it responds to treatment. This test is not enough on its own to make a diagnosis, and needs to be used alongside other tests such as scans.
A CT (computerised tomography) scan takes a series of x-rays which builds up a three- dimensional picture of the inside of the body. The scan is painless, but takes from 10 to 30 minutes. CT scans use a small amount of radiation, which is very unlikely to harm you and will not harm anyone you come into contact with. You'll be asked not to eat or drink for at least four hours before the scan.
Having a CT scan
You may be given a drink or injection of a dye which allows particular areas to be seen more clearly. This may make you feel hot all over for a few minutes. If you are allergic to iodine or have asthma you could have a more serious reaction to the injection, so it's important to let your doctor know beforehand.
CT scans can be used to guide a biopsy, in which a small amount of tissue is taken for examination under a microscope. You'll be told if this is planned.
You will probably be able to go home as soon as the scan is over.
Ultrasound uses sound waves to look at internal organs, such as the pancreas and the liver. You'll usually be asked not to eat or drink anything for at least six hours before the test.
Once you are lying comfortably on your back, a gel is spread on to the area to be scanned. A small device that produces sound waves is passed over the area. The sound waves are then converted into a picture by a computer. This test only takes a few minutes.
As with CT scans, an ultrasound can be used to guide a biopsy, in which tissue is taken for examination under a microscope.
An MRI (magnetic resonance imaging) scan is similar to a CT scan, but uses magnetic fields instead of x-rays to build up a series of cross-sectional pictures of the body.
During the test you will be asked to lie very still on a couch inside a metal cylinder that's open at both ends. The whole test may take up to an hour and is painless – although the machine is very noisy. You'll be given earplugs or headphones to wear.
The cylinder is a very powerful magnet, so before going into the room you should remove all metal belongings including jewellery. You should also tell your doctor if you have ever worked with metal or in the metal industry or if you have any metal inside your body (for example, a cardiac monitor, pacemaker, surgical clips, or bone pins). You may not be able to have an MRI because of the magnetic fields.
Some people are given an injection of dye into a vein in the arm, but this usually does not cause any discomfort.
You may feel claustrophobic inside the cylinder, but you may be able to take someone with you into the room to keep you company. It may also help to mention to the staff beforehand if you do not like enclosed spaces. They can then offer extra support during your test.
ERCP (endoscopic retrograde cholangio pancreatography) enables the doctor to take an x-ray picture of the pancreatic duct and the bile duct. The bile duct can be unblocked during this procedure if necessary.
Before the test, you will be asked not to eat or drink anything for about six hours so that the stomach and small bowel (duodenum) are empty. You will be given an injection to help you to relax and some local anaesthetic will be sprayed on to the back of your throat. The doctor will then pass a thin, flexible tube, known as an endoscope, into your mouth, through your stomach and into the duodenum.
Looking down the endoscope, the doctor can find the opening where the bile duct and the pancreatic duct drain into the duodenum. A dye that can be seen on x-ray is then injected into these ducts to show up any abnormalities or any blockage of the duct.
You'll usually be given an injection of antibiotics before the test, to prevent any infection.
Most people are ready to go home a couple of hours after their test. It's a good idea to arrange for someone to collect you from the hospital as you shouldn't drive for several hours after a sedative.
EUS (endoscopic ultrasound)
A newer test that is sometimes used instead of an ERCP, is an endoscopic ultrasound (EUS). This is a similar procedure to an ERCP, but involves an ultrasound probe being passed down the endoscope, to take an ultrasound scan of the pancreas and surrounding organs. Ultrasound uses high-frequency sound waves to build up a picture. Biopsies can also be taken during an EUS.
If your doctor strongly suspects that you have cancer of the pancreas, they'll usually suggest that you have a biopsy to confirm the diagnosis. This involves removing some cells or a small piece of tissue, from the tumour, to be looked at under a microscope.
A biopsy can be taken in a number of ways. It may be possible to insert a needle through the skin of the abdomen to take a small piece of tissue, using an ultrasound or
CT scan for guidance. You'll be given an injection of local anaesthetic to numb the area so that you feel little or no pain from the insertion of the needle.
Another way is to take some cells during an ERCP or an EUS.
This test involves a small operation done under a general anaesthetic and will mean a short stay in hospital. It allows the doctor to look at the area of the pancreas and see whether an operation will be possible.
The doctor makes a small cut (about 2cm/1inch) in the skin and muscle near the navel and carefully inserts a thin, fibre-optic tube (laparoscope) into your abdomen. The doctor can then examine the area and take a sample of tissue (biopsy) for examination under the microscope. Sometimes gas is pumped into the abdomen to make it easier for the doctor to see the pancreas. The gas will not harm you and it will gradually disappear after the laparoscopy.
If the above tests do not give a definite diagnosis, an operation to look inside the abdomen (called a laparotomy) may be done under a general anaesthetic. It's rare for a laparotomy to be needed as most people can have a laparoscopy.
ERCP, biopsy and laparoscopy can cause problems for some people. Your specialist should discuss any possible risks with you before you have any of these procedures.
Waiting for your test results
It will probably take several days for the results of your tests to be ready and this waiting period will obviously be an anxious time for you. It may help if you can talk things over with a relative or close friend. You may wish to ring our information service or another support organisation for emotional support.
Staging of pancreatic cancer
The stage of a cancer is a term used to describe its size and whether it has spread beyond the area of the body where it started. Knowing the extent of the cancer helps the doctors to decide on the most appropriate treatment.
Generally, pancreatic cancer is divided into four stages: small and localised (stage one); spread into surrounding structures (stages two or three); or spread into other parts of the body (stage four). If the cancer has spread to distant parts of the body this is known as secondary cancer (or metastatic cancer).
A commonly used staging system is described below.
Stage 1 This is the earliest stage. The cancer can only be found inside the pancreas itself, although it may be quite large. There is no cancer in the lymph nodes close to the pancreas and no sign that it has spread to anywhere else in the body.
Stage 2 The cancer has started to grow into the duodenum or bile duct, or other tissues or organs close to the pancreas. There is no cancer in the nearby lymph nodes.
Stage 3 The cancer can be any size and may have spread into the tissues surrounding the pancreas.
Stage 4 These cancers are divided into 4A and 4B.
4A means the cancer has grown into organs close to the pancreas, such as the stomach, spleen, large bowel or large blood vessels nearby. Cancer may or may not be present in the lymph nodes.
4B means the cancer has spread to other body organs such as the liver or lungs.
TNM staging system
Another staging system known as the TNM system is commonly used. This can give more precise information about the extent of the cancer.
T describes the size of the tumour.
N describes whether the cancer has spread to the lymph nodes.
M describes whether the cancer has spread to another part of the body (secondary or metastatic cancer).