Diagnosis of cancer often begins when a person notices an unusual health symptom and consults a doctor. Early warning signs of cancer include changes in bowel or bladder habits, a sore that does not heal, unusual bleeding or discharge, thickening or a lump in the breast or any other part of the body, indigestion or difficulty swallowing, change in appearance of a wart or mole, or a nagging cough or hoarseness.
There is no single test that can accurately diagnose cancer. The complete evaluation of a patient usually requires a thorough history and physical examination along with diagnostic testing. Many tests are needed to determine whether a person has cancer, or if another condition (such as an infection) is mimicking the symptoms of cancer. Effective diagnostic testing is used to confirm or eliminate the presence of disease, monitor the disease process, and to plan for and evaluate the effectiveness of treatment. In some cases, it is necessary to repeat testing when a personís condition has changed, if a sample collected was not of good quality, or an abnormal test result needs to be confirmed. Diagnostic procedures for cancer may include imaging, laboratory tests (including tests for tumor markers), tumor biopsy, endoscopic examination, surgery, or genetic testing.