The aim of these guidelines is to facilitate appropriate referral between primary and secondary care for patients whom a GP suspects may have cancer. The guidelines should help GPs to identify those patients who are most likely to have cancer and who therefore require urgent assessment by a specialist. Equally it is hoped that the guidelines will help GPs to identify patients who are unlikely to have cancer and who may appropriately be observed in a primary care setting or who may require non-urgent referral to a hospital.