PANCREATIC CANCER

What is the pancreas?
The pancreas is an important gland located in the abdomen, slightly behind your stomach and in front of your spine. The pancreas is about 25 cm long and is shaped like a tadpole. It produces digestive enzymes, which are secreted into the duodenum (the first part of your small intestine) to help break down the food you have eaten. It also produces the hormones insulin and glucagon, which balance the sugar levels in your blood and body cells.

What is pancreatic cancer?
‘Pancreatic cancer' is a broad term used to describe as many as 20 different types of tumour that can occur in the pancreas. Each type requires a different treatment and has a different prognosis.

The pancreas is part of both the endocrine and exocrine systems of the body. The endocrine system includes the glands that secrete hormones directly into the bloodstream. The exocrine system consists of glands that secrete outwards through ducts onto the surface of the gut or the skin.

Pancreatic cancer is often categorised as being either non-endocrine (that is, it does not affect the hormone-producing cells of the pancreas) or endocrine (where it can have dramatic effects on the amounts of hormones produced). Non-endocrine tumours make up the majority of pancreatic cancers (more than 90 per cent). The endocrine tumours are much less common.

Adenocarcinoma, a type of non-endocrine malignancy, is the most common form of pancreatic cancer. It is responsible for about three-quarters of all cases, and is the form most people refer to when talking about pancreatic cancer.

Endocrine tumours, such as tumours of the hormone-producing islet cells of the pancreas, occur only rarely (in about one per cent of pancreatic cancer cases). Insulinomas, for example, may cause excessive insulin production resulting in low blood sugar, while glucagonomas may cause excessive glucagon production, resulting in a distinctive skin rash.

What are the risk factors for pancreatic cancer?
Pancreatic cancer is a genetic disease, caused by abnormal changes in the DNA within the body's cells. These changes may be inherited, acquired by chance, or be the result of exposure to certain carcinogens (cancer-causing substances), for example, tobacco smoke.

The following are some of the risk factors that may potentially increase your chance of getting pancreatic cancer:

What are the symptoms of pancreatic cancer?
Unfortunately, the symptoms of pancreatic cancer do not usually occur until the disease is well advanced, making early diagnosis quite difficult. Because the pancreas is located deep within the abdomen, it is difficult for your doctor to feel any abnormalities in the pancreas itself. Also, the symptoms often do not appear until the tumour has grown big enough to interfere with the function of nearby organs, such as the liver and stomach, or to invade the nerves.

When they do develop, the symptoms of pancreatic cancer may include:

How is pancreatic cancer diagnosed?
Diagnosis of pancreatic cancer can involve several methods of imaging the pancreas. A CT scan of the abdomen usually provides detailed pictures of the pancreas. However, other diagnostic procedures may be carried out. These include the following.

•  Ultrasound of the abdomen, where sound waves are bounced off the internal organs and make a picture on a scanner.

•  Endoscopic ultrasound, where an endoscope is passed down the throat into the stomach to see if the cancer has spread, used in conjunction with ultrasound /images.

•  Endoscopic retrograde cholangiopancreatography, where an endoscope is passed down the throat through the stomach to the duodenum where the common opening to the pancreatic and bile ducts can be seen and X-rays taken of the duct system.

•  Laparoscopy, where a tiny camera is inserted through a cut in the wall of the abdomen.

•  Biopsy, either through fine needle aspiration (long thin needle passed through abdomen wall) or through surgical removal of tissue.

How is pancreatic cancer treated?
The options for treating pancreatic cancer include surgery, radiation, chemotherapy or a combination of these techniques. Surgery is generally only undertaken if the cancer has not spread.

The surgical removal of most pancreatic cancers is done using a technique known as the ‘Whipple procedure' or ‘pancreaticoduodenectomy'. This complex operation often involves not only removing part or all of the pancreas, but also the gallbladder, part of the bile duct, part of the stomach, parts of the small intestine, and all of the regional lymph nodes (those lymph nodes that drain lymphatic fluid from the region of the tumour).

Unfortunately many pancreatic cancers cannot be surgically removed, and in these cases radiotherapy and/or chemotherapy are used to help manage the symptoms. A number of other pain management techniques may also be employed. These include palliative surgery to perform nerve blocks or to clear blockages to the bile duct and stomach, as well as the administration of pain-relieving medications.

What is the prognosis for people with pancreatic cancer?
Pancreatic cancer is a very serious disease, especially after it has spread to nearby organs and lymph nodes. Fewer than 10 per cent of tumours are diagnosed while the cancer is still confined to the pancreas. Most have already spread further. Also, the larger the tumour the less likely it is that it can be cured by surgery.

Hope for the future
Additional therapies, such as a combination of chemoradiation and immunotherapy techniques, are currently being investigated as a way of increasing survival rates for people with pancreatic cancer. Similarly, new developments in the field of molecular genetics may one day help detect the cancer at an earlier stage in its development, allowing earlier surgical intervention and higher survival rates.