Hereditary cancers are those that develop because of inherited mutations in a specific gene. Genes are the units of genetic information that tell the cells of our bodies how to work and grow. Just like some genes control what colour of hair we have or how tall we will be, some genes help to protect us from getting cancer. A gene mutation prevents a gene from working properly and can be passed from parents to children. This is why it can look like cancers “run” in a family. This does not mean that everyone who has inherited a gene mutation will get cancer – but rather that their chance of developing cancer is higher than the average person.
Because most cancers are not hereditary, we use clues to tell us whether or not a cancer is likely to be hereditary. For example, the type of cancer, the age that someone is diagnosed with cancer and the number of people in a family who have been diagnosed with cancer are all important clues.