Cancer Health Center

How Is Cancer Diagnosed?

The earlier cancer is diagnosed and treated, the better the chance of its being cured. Some types of cancer -- such as those of the skin, breast, mouth, testicles, prostate, and rectum -- may be detected by routine self-exam or other screening measures before the symptoms become serious. Most cases of cancer are detected and diagnosed after a tumor can be felt or when other symptoms develop. In a few cases, cancer is diagnosed incidentally as a result of evaluating or treating other medical conditions.

Cancer diagnosis begins with a thorough physical exam and a complete medical history. Laboratory studies of blood, urine, and stool can detect abnormalities that may indicate cancer. When a tumor is suspected, imaging tests such as X-rays, computed tomography (CT), magnetic resonance imaging (MRI), ultrasound, and fiber-optic endoscopy examinations help doctors determine the cancer's location and size. To confirm the diagnosis of most cancers , a biopsy needs to be performed in which a tissue sample is removed from the suspected tumor and studied under a microscope to check for cancer cells.