Lung cancer may be detected in a variety of different ways. Sometimes, the person may not have any signs of the disease, but it may be discovered during other medical procedures e.g. a chest X-ray during a routine checkup prior to other surgery. For those people who do experience symptoms, these may give clues to suspect lung cancer, which is then confirmed by medical tests. Others may not have any early signs of the disease, but may go to the doctor due to other symptoms which may indicate advanced stage disease (when the tumour has spread to other parts of the body).