For a long time there have been theories that cancer can be caused by thought processes, unconscious thinking or stress in our daily lives. However, there is no evidence that our state of mind could affect our risk of cancer. Scientists have clearly shown that cancer is a physical process. It’s what happens when the genes in our cells become damaged, or stop working properly. This can happen as a natural part of ageing, or because of things in our environment like tobacco, alcohol or sunlight. While the way we think can affect the way we cope with cancer after we’re diagnosed, it doesn’t influence whether we develop the disease in the first place.