This booklet for patients and carers describes pancreatic cancer, its causes and symptoms. It gives detailed information on the diagnostic tests used and the stages of pancreatic cancer. It includes a section on what to ask your doctor, where to go for further information and a glossary to explain many of the terms used.
Genetics: risk factor of pancreatic cancer
Most cases of pancreatic cancer are not inherited, and the cause is unknown. However, some genetic conditions and family traits can give you a higher chance of getting the disease.
Genes and pancreatic cancer
Genetics are non-modifiable. You cannot change the genes you inherit. However, you can manage your risk once you are aware of it.
What are genes?
Genes are sections of DNA inherited from our parents. Everyone has two copies of each gene, one from their father and one from their mother. Everyone is different, and small differences in our genes create the differences seen between people.
Genes act as a code to every process in the body. We have hundreds of thousands of genes, each with its own function. If genes are not functional, somehow (mutated) cells can grow out of control and cause cancer. If these genes are passed onto children, they have an increased chance of developing cancer.
If a close relative has had pancreatic cancer or you have any of the inherited conditions below, you can discuss your risk with your doctor.
Family history is a non-modifiable risk factor which means you cannot change the genes you inherit. However, you can manage your risk once you are aware of it.
Remember – most pancreatic cancers appear out of the blue when there is no family history of the disease. Some gene mutations can be tested for, however there is currently no way to predictive gene test for all pancreatic cancers.
What is familial pancreatic cancer?
This is when pancreatic cancer runs in families, however, this is very rare, affecting between 5-10% of all cases. Most cases of pancreatic cancer occur out of the blue with no family history of the disease. Familial pancreatic cancer is when a certain gene is passed on from a parent to their child, this gene then increases the chance of developing certain cancers. Examples include;
- Families with two or more first-degree relatives (parent, sibling, offspring) with pancreatic cancer.
- Families with three or more relatives with pancreatic cancer.
- Families with an associated cancer syndrome and at least one case of pancreatic cancer. This includes families with gene mutations on BRCA1, BRCA2, PALB2 or CDKN2A (p16) and one or more first-degree relatives with pancreatic cancer, Familial Atypical Multiple Mole Melanoma (FAMMM) syndrome, Hereditary Non-Polyposis Colorectal Cancer (HNPCC) (also called Lynch syndrome) and Peutz-Jeghers syndrome. See below for more information. (links to below information on each)
- Hereditary pancreatitis and a PRSS1 gene mutation
What are genes?
Genes are sections of DNA inherited from our parents. Everyone has two copies of each gene, one from their father and one from their mother. Everyone is different and small differences in our genes create the differences seen between people.
Genes act as a code to every process in the body. We have hundreds of thousands of genes, each with their own function. If genes are not functional in some way (mutated) cells can grow out of control and cause cancer. If these genes are passed onto children, they have an increased chance of developing cancer.
Why is this relevant to pancreatic cancer?
Pancreatic cancer runs in some families. People with first degree relatives (mother, father, brother, sister) diagnosed with pancreatic cancer have an increased chance of pancreatic cancer themselves. The greater the number of first degree relatives with pancreatic cancer the greater this risk is.
Family history is a strong predictor of pancreatic cancer risk because it is suggestive of the presence of a genetic link to pancreatic cancer, although lifestyle factors also play a role, such as smoking and obesity.
If you have a greater chance of developing pancreatic cancer because of your family history, you may want to become familiar with the symptoms of the disease so that, if you suffer any symptoms, you can go to your GP sooner to catch the disease earlier.
Can I get tested?
Unfortunately, there is currently no genetic test for pancreatic cancer. In many families, the genes that might cause pancreatic cancer are unknown. Research by EUROPAC (European Registry of Hereditary Pancreatitis and Familial Pancreatic Cancer) aims to identify gene changes that may increase risk in these families. This may be a way to get involved and check your family’s genes.
Most cases of pancreatic cancer do not run in families, but there are some rare medical syndromes which are known to increase the risk of pancreatic cancer.
Rare syndromes and pancreatic cancer risk
The syndromes outlined below are rare conditions, if you have any of these it is very likely you will already know about it. Unless you have the gene mutations (below) and/or have a family member with other types of cancer, your genetic and inherited risk of having pancreatic cancer is very small.
Pancreatitis itself is fairly common however, hereditary pancreatitis is quite rare. It is a genetic condition usually involving the development of several episodes of severe chronic pancreatitis which starts at an early age (usually between the ages of 5 and 26 but can occur at any time). Patients with recurring episodes of pancreatitis are recognised as being at an increased risk of developing pancreatic cancer.
Familial Breast Cancer Gene (BRCA2)
A small percentage (5-7%) of pancreas cancers are caused by inherited defects in the BRCA1 OR 2 gene. Gene testing for BRCA2 mutations is available.
Hereditary Colon Cancer
The HNPCC (Hereditary Non-polyposis Colorectal Cancer) syndrome is an inherited predisposition to develop colon cancer, pancreatic cancer, endometrial (uterine) cancer, stomach cancer and ovarian cancer. Gene testing for HNPCC is available.
The FAMMM (Familial Atypical Multiple Mole Melanoma) syndrome is a rare hereditary syndrome which increases melanoma risk (an aggressive form of skin cancer) in some families. These patients also have an increased chance of developing pancreatic cancer.
This is an extremely rare syndrome in which affected family members develop polyps (abnormal tissue growths) on the surface of their small intestines and pigmented spots on their lips. These patients have a greater chance of developing pancreatic cancer and other cancers. Click here for more information on PJS syndrome.
Ataxia telangiectasia is a primary immunodeficiency disease which affects a number of different organs in the body. An immunodeficiency disease is one that causes the immune system to break down, making the body susceptible to diseases. It is a rare, recessive genetic disorder of childhood that occurs in 1 out of 40,000 – 100,000 people worldwide. Cancer risk is increased in people with the condition including pancreatic and breast cancers.
If you are concerned, please follow the link to download “I have a family history of PC – what are the risks and what should I do?” written by Dr Bill Greenhalf from the Liverpool Centre of EUROPAC.
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|Information Product №||Published||15/10/2019|
|Last Updated||21/04/2022||Next Review Due||15/10/2022|