Can a physical blow or injury cause cancer?
Though one study suggests a link between physical trauma to the breast and breast cancer, the study was very small and there were many problems with how it was conducted. Its findings have not been duplicated.
A diagnosis of cancer can happen soon after a physical injury - but this is because the exam or test for the injury leads to the discovery of a cancer. For example, a bone that is weak from a cancerous tumour is more likely to break if hit, and treating the broken bone leads to the discovery of the cancer.
Injuries cannot cause cancer but an injury may lead to finding cancer in the injured area.