Around a quarter of those in the developed world die of cancer. Most cancers present to primary care with symptoms, even when there is a screening test for the particular cancer. However, the symptoms of cancer are also symptoms of benign disease, and the GP has to judge whether cancer is a possible explanation. Very little research examined this process until relatively recently. This review paper examines the process of primary care diagnosis, especially the selection of patients for rapid investigation. It concentrates on the four commonest UK cancers: breast, lung, colon, and prostate as these have been the subject of most recent studies.
