We do know that cancer isn’t contagious though. You don’t catch it from people, and you can’t pass it on to others.
For a few cancers, there might be a genetic link (meaning a higher risk of cancer runs in the family). For others, a viral infection may increase the risk of developing cancer.
It’s possible that some cancers start before you are born, when your cells are dividing rapidly while you are still in the womb. Cancers such as bone tumours in young people may also be related to periods of fast growth when the cells are dividing rapidly, but their exact cause is not known.
You’ve probably heard that smoking or a poor diet increases your risk of cancer. While this may be true in middle-aged or older people, it’s very unlikely that any lifestyle choices have caused your cancer.
So you’ve no need to feel guilty, or to blame yourself or anyone else.
Updated December 2014, next planned review 2017.