If you have been diagnosed with cancer or have a family history of cancer, one of the main questions to naturally cross your mind is – can cancer run in a family? The answer is Yes – the risk to develop cancer or, in other words, the predisposition to cancer, can pass down from one generation to the next.
Cancer is multi-factorial, implying that it is caused by a combination of factors, including age, family history, lifestyle, environmental and genetics risk factors. Most cancer is sporadic, meaning that it happens randomly as an isolated event. 5-10% of all cancers are caused by a hereditary cancer syndrome related to a gene mutation that a person is born with. 15-20% of all cancers are familial in nature and for these families, genetic testing might not identify a causal gene mutation.
For a quick recap, our bodies are made up of cells and within each cell we have genes, made up of DNA, that have information for how the body is supposed to function. If there is a change in a gene, called a mutation, it can cause a corresponding health issue. There are a group of genes which have information related to cancer, for example, how should the body fight cancer. If there is a mutation in one of these genes, a person might be at an increased risk to develop certain cancers associated with that hereditary cancer syndrome. This individual’s family members, including children and siblings, are also at a risk of inheriting this gene mutation. If a person is identified to have a hereditary cancer syndrome, there are established guidelines or recommendations for cancer screening and surveillance.
There are certain ‘red flags’ in an individual’s medical and family history, which can point towards the possibility of an underlying hereditary cancer syndrome. Some of these red flags are:
– Multiple individuals in a family diagnosed with cancer
– An Individual diagnosed with multiple cancers
– Cancer diagnosed at a really young age (typically <50 years at the time of diagnosis)
– Certain rare cancers and certain cancer pathologies
In certain families, there might be multiple individuals and generations affected with cancer although we may not be able to identify a certain pattern or an underlying hereditary cancer syndrome. Individuals from these families with familial cancer can also benefit from targeted cancer screening and surveillance.
A genetic counselor can help you understand your risk to develop cancer based on your medical and family history. A genetic counselor can also help identify the most appropriate genetic test for you and further help interpret genetic testing results and make recommendations as needed. Genetic counselors can be a valuable source of information and help you make medical decisions that are best for you. A genetic counselor can also serve as a compassionate resource and a source of emotional support.
A genetic counseling session typically includes obtaining a thorough medical and family history from the patient. The discussion usually encompasses an explanation of genetics and a risk assessment based on the obtained history. The genetic counselor may then discuss the option of genetic testing if relevant. A genetic counselor can also help with making recommendations with respect cancer surveillance which can help reduce your cancer risk or identify cancer at an early stage.
If you would like to understand your genetic risk to develop cancer or the risk for your family members to develop cancer or if you are interested in pursuing cancer genetic testing, please contact AT-GC to meet with a genetic counselor.