What is it?
For an explanation of the pancreas, please see the description under "What is the pancreas?" in Pancreatic Diseases.
Cancer is an uncontrolled growth of cells that form tumours; which damage normal tissue and may eventually spread to the other parts of the body (metastasise). Most pancreatic cancers (95%) are adenocarcinomas that develop in the pancreatic ducts and sometimes in the enzyme-producing cells of the exocrine tissue. Endocrine tumours are usually less aggressive than exocrine tumours and are rarer. They may be benign tumours that do not metastasise (such as an insulinoma) or malignant, including a group of cancers called islet cell cancers. Endocrine cancers are usually detected earlier than exocrine cancers because they often produce excessive amounts of the hormones insulin and glucagon that frequently result in the development of characteristic symptoms.
The remainder of this discussion focuses on exocrine cancer because it is more common and the tumours are more aggressive. Unfortunately, they are hard to detect at an early stage. Since the pancreas is deep in the body, tumours usually cannot be seen or felt during a physical examination and, by the time symptoms develop, the cancer has often spread throughout the pancreas and beyond. One exception to this is a cancer that forms at the ampulla, the point where the pancreatic and bile ducts empty into the duodenum. Ampullary cancer often obstructs the flow of bile from the bile duct and causes jaundice, so it has the potential to be detected earlier than most exocrine cancers.
According to Cancer Research UK, about 10,000 people are diagnosed with pancreatic cancer in the UK each year. It is the 11th most common cancer in the UK and is more common in older people.
Early symptoms of pancreatic cancer are often either absent or subtle. They include abdominal pain, back pain, nausea, loss of appetite, unexplained weight loss and jaundice. Since these symptoms can be experienced in conditions other than cancer, they may be ignored or misinterpreted in the early stages. By the time chronic pain, vomiting, impaired digestion of food and problems with blood sugar control surface and are recognised, the pancreatic cancer has often become firmly established.
Unfortunately, there are no laboratory tests available for the early detection or diagnosis of pancreatic cancer. The diagnosis is usually made using a combination of the results of a clinical examination, clinical history, imaging tests and biopsy.
Laboratory tests that may be abnormal but are not diagnostic of pancreatic cancer (i.e. can be abnormal as a result of other conditions) include:
- Amylase: this may be raised if the tumour obstructs the ducts through which pancreatic juice flows to the intestine
- Liver function tests: an elevated bilirubin concentrations suggests the tumour itself or glands it has spread to are blocking the bile duct. A raised ALT suggests that the tumour has spread to the liver
- Calcium: this is sometimes raised in pancreatic cancer (as in other cancers), producing symptoms such as weakness, nausea, abdominal pain and thirst. A raised calcium caused by cancer can be treated and the symptoms relieved
- CA 19-9 (Cancer Antigen 19-9): a tumour marker that can be used for monitoring response to treatment. It is not useful for detection or diagnosis because it is not elevated in all cases and it is not specific for pancreatic cancer (it may be elevated as a result of other conditions). If it is raised at diagnosis it may then be used to assess the efficiency of treatment and to monitor for recurrence.
- CEA (Carcinoembryonic antigen): a tumour marker that may also be used to monitor the response to treatment and for recurrence, if the concentration is raised at diagnosis.
- Other tests such as stool chymotrypsin or elastase, blood immunoreactive trypsin (IRT), amylase, and lipase may be measured to help determine how well the pancreas is functioning and whether pancreatic enzyme supplementation is necessary
Non-laboratory tests that may be used:
- CT (computed tomography) scan: useful for detecting pancreatic masses and any cancer that has spread to other areas of the body.
- Biopsy: used to confirm diagnosis of cancer, often in conjunction with CT scan
- ERCP (endoscopic retrograde cholangiopancreatography): test that uses a flexible endoscope tube inserted through the nose, stomach and into the pancreas which may be used to introduce a dye for X-rays, to place a stent (a metal or plastic tube that can help keep a duct open and functioning) or to take a biopsy
- Transabdominal ultrasound
- MRI (magnetic resonance imaging)
The main risk factor for pancreatic cancer is smoking. About 20% of pancreatic cancers in the UK are thought to be a direct result of cigarette smoking. Other risks include:
- Age: 75% occur in people 65 or older
- Gender men are 30% more likely to develop pancreatic cancer
- Chronic pancreatitis
- Diet: a diet high in red meat and fat appears to increase risk
- Diabetes mellitus
- Exposure to some industrial chemicals, such as certain pesticides and petroleum products
- Family history: an inherited tendency may be a factor in 5% to 10% of cases
It should be noted that most people who have known risk factors do not get pancreatic cancer, and many who do get pancreatic cancer have none of these risk factors.
Treatment of pancreatic cancer centres first around staging - determining how much of the pancreas is involved and whether the cancer has spread. This may be done using a formal staging/naming system or by categorising the cancer into resectable (within the pancreas and surgically removable), locally advanced (spread into nearby organs and not removable) or metastatic (spread to distant organs).
Unfortunately resection (removal) is possible less than 15% of the time. How much surgery is done depends on where the tumour is located, its size, how far it has spread, and the patient's health. Pancreatic surgery is very difficult. It requires an experienced surgeon, is associated with significant complications, and requires several weeks of recovery time. Procedures include:
- Whipple procedure: the surgeon removes the head of the pancreas and part of the small intestine, bile duct, and stomach
- Distal pancreatectomy: the body and tail of the pancreas and the spleen are removed
- Total pancreatectomy: the pancreas, part of the small intestine, some of the stomach, the common bile duct, the gallbladder, the spleen, and nearby lymph nodes are removed
Radiation and chemotherapy may also be used and are often necessary as tiny, undetectable amounts of the tumour have often spread by the time surgery is done. Unfortunately, pancreatic cancer often does not respond well to current available treatments. Gemcitabine and 5-fluorouracil (5-FU) are the most commonly used chemotherapy agents. They may be used alone or in combination with other drugs or radiation therapy.
These are the chemotherapy drugs used for pancreatic cancer, and how they are used together. The brand name of each drug is in brackets.
FOLFIRINOX – a combination of oxaliplatin (Eloxatin®), folinic acid (leucovirin), irinotecan and Fluorouracil (5-FU)
Gemcitabine (Gemzar®)
GemCap - gemcitabine and capecitabine (Xeloda®)
FOLFOX - oxaliplatin, fluorouracil and folinic acid
Nab-paclitaxel (Abraxane®) with gemcitabine.
For those with recurring or inoperable pancreatic cancer, palliative (comfort-oriented) care is often the main priority. Radiation, chemotherapy, and surgery may be used to help relieve pain. Surgery also may be done on non-resectable cancers to remove or bypass blockages in the bile duct and to help relieve pain and jaundice. An ERCP procedure may be done with a flexible endoscope to place a stent (plastic or metal tube that can help keep the duct open). Surgery also may be performed to cut nerves to help relieve pain that is resistant to other measures.
People with inoperable pancreatic cancer also may consider enrolment in clinical trials of new treatments. There are promising areas of research that may offer them additional options.