About pancreatic cancer
Pancreatic cancer occurs when cells in the pancreas develop mutations in their DNA that can cause cells to grow into tumours. The pancreas lies behind the lower part of the stomach and secretes enzymes to help digestion and hormones to help with the metabolism of sugars.
‘Pancreatic adenocarcinoma’ originates in the part of the pancreas that makes digestive enzymes and accounts for about 85% of cases, but this part of the pancreas can also produce other rarer types of cancers. About 2% of pancreatic cancers are known as ‘neuroendocrine tumours’ that affect the hormone-producing cells of the pancreas and are generally less aggressive.
- Symptoms & Diagnosis
As little is yet known about the causes of pancreatic cancer it can be difficult to explain why some people develop the disease and others don’t. Pancreatic cancer is fundamentally a genetic disease and can be caused by mutations or changes in a person’s DNA that can be due to inheriting a faulty gene or acquiring one as we age.
Pancreatic cancer is unusual before the age of 40, and 80% of cases are diagnosed in people over the age of 60 years. Risk factors for pancreatic cancer include tobacco smoking, obesity, diabetes and certain rare genetic conditions.
There may be a genetic link in up to one in 10 cases of pancreatic cancer and a number of gene mutations can increase your risk, including breast cancer gene 2 (BRCA2), Peutz-Jeghers Syndrome, Familial Atypical Multiple Mole Melanoma (FAMMM), Hereditary Non-Polyposis Colorectal Cancer (HNPCC) and hereditary pancreatitis.
Chronic pancreatitis or long-term inflammation of the pancreas appears to almost treble the risk and hereditary pancreatitis can increase the risk of pancreatic cancer by 30–40%.
Other minor risk factors may include a diet high in red meat and/or saturated fat and low in fruits and vegetables, as well as frequent exposure to some pesticides and petroleum products.
Signs and symptoms may not appear until pancreatic cancer is quite advanced and the cancer is large enough to affect nearby organs – at this stage complete surgical removal isn’t possible. These signs include:
- upper abdominal or back pain
- jaundice (yellowish skin and eyes)
- dark urine
- loss of appetite
- weight loss
- blood clots.
Some earlier signs and symptoms associated with pancreatic cancer may also include:
- nausea and vomiting
- change in bowel motions – either diarrhoea or severe constipation.
Pancreatic cancer can only be confirmed following a number of tests, including blood tests, imaging tests like CT scans or ultrasound, endoscopic tests and tissue sampling or biopsy, and will depend on the symptoms, type and stage of the cancer. The tests will help to pinpoint where in the pancreas the cancer is and whether it has spread to nearby organs or other parts of the body.
Pancreatic adenocarcinoma typically has a very poor prognosis, with only 25% of people surviving one year after diagnosis and 5% for five years. Even when diagnosed early, the five-year survival rate only rises to about 20%. Neuroendocrine cancers can have better outcomes with a 65% five-year survival rate.
Treatment options for pancreatic cancer differ from patient to patient and are based on several factors, including stage and location of the cancer, the age of the patient and general health. Advanced pancreatic cancer can only rarely be treated with the aim of curing the cancer.
Pancreatic cancer can be treated with surgery, radiotherapy, chemotherapy or palliative care, or a combination of these. Surgery is the only treatment with potential to cure the disease, but it may also be carried out to try to simply improve quality of life.
- Surgery – the most common surgery is the ‘Whipple procedure’ where the head of the pancreas is removed along with the duodenum, gall bladder, bile duct and part of the stomach. Enough of the pancreas is left to maintain some function. Surgery can also complete removal of the pancreas or particular sections depending on the location of the tumour.
- Endoscopic treatment uses a stent to allow bile to drain from the liver if the tumour is blocking the bile duct.
- Chemotherapy uses anti-cancer drugs to prevent the cancer from growing and is sometimes used in combination with radiotherapy.
- Radiation therapy uses high-energy x-rays to shrink or destroy cancer cells in the tumour and can be used to treat cancer that has not spread, but cannot be removed with surgery. It may also be used to relieve symptoms.
Targeted therapy using drugs that attack specific abnormalities within cancer cells, such as erlotinib (Tarceva) that blocks chemical signals causing cancer cells to multiply, can be combined with chemotherapy for people with advanced pancreatic cancer.
As pancreatic cancer spreads to nearby lymph nodes, the liver, the peritoneal cavity-the fluid-filled gap between the walls and the organs in the abdomen-large intestine or lungs, the increasing burden of symptoms means that the primary medical focus is on making the patient comfortable.
The treatment and survival of patients with pancreatic cancer has not changed for more than 30 years, partly because there has been little research into the molecular and cell biology associated with it. This is why Garvan’s pancreatic cancer research teams are searching for a new understanding of how this disease develops, better ways to treat it and stop it spreading.