Individuals who have a family history of cancer are unnecessarily worried about their own risks, a poll shows.
The charity Cancerbackup carried out a survey of more than 1,000 people as part of its "What Now?" campaign targeted at debunking myths surrounding genetics and cancer.
The poll showed that 91% of people believed that if they have a relative with cancer then they also have a greater than average risk themselves.
In reality, having a relative with cancer may not significantly increase someone's risk of developing cancer at all.
Some 60% of people thought that family history is the biggest risk factor for developing cancer and only 15% realise it is actually age.
Only 13% of people knew that just 5-10% of cancers are known to be hereditary while a quarter thought half of cancers run in the family.
"Worrying about cancer can be very debilitating and it is sad that people are not aware of the reality, that very few cancers are caused by a known inherited genetic link," says Cancerbackup Genetic Information Manager Dr Andrea Pithers.
"At the same time people should know about how they can lower their risk with things they can actually change, like eating a healthy diet and exercise."