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Diagnostic Tests

There is a wide array of methods to diagnose cancer. As researchers learn more about the mechanisms of cancer, new diagnostic tools are constantly being developed and existing methods refined. If your primary care physician suspects cancer, he or she may order some tests to confirm the diagnosis. These tests can either be conducted by your physician or by oncologists at cancer centers like MD Anderson. No matter who makes the diagnosis, a second opinion by a cancer expert is strongly recommended. Some types of cancer, particularly lymphomas, can be hard to classify, even for an expert. Accurate identification of cancer allows oncologists to choose the most effective treatment. The most common diagnostic methods include:


A small tissue sample is surgically removed and examined under a microscope for the presence of cancer cells. Depending on tumor location, some biopsies can be done on an outpatient basis with only local anesthesia. If the tumor is filled with fluid, a type of biopsy known as a fine needle aspiration is used. A long, thin needle is inserted directly into the suspicious area to draw out fluid samples for examination.


A flexible plastic tube with a tiny camera on the end is inserted into body cavities and organs, allowing the physician to view the suspicious area. There are many types of scopes, each designed to view particular areas of the body. For instance, a colonoscope is used to detect growths inside the colon, and a laparoscope is used to examine the abdominal cavity.

Diagnostic Imaging

MD Anderson uses several diagnostic imaging techniques to produce internal pictures of the body and its structures. These images are usually taken by a trained technician and then analyzed by a radiologist, a physician who specializes in interpreting diagnostic images. The images and the radiologist’s findings are then sent to the patient’s primary care center, where doctors use the information to form a care plan.

Blood Tests

Some tumors release substances called tumor markers, which can be detected in the blood. A blood test for prostate cancer determines the amount of prostate specific antigen (PSA). Higher than normal PSA levels can indicate cancer. Recently, a blood test for ovarian cancer, known as CA-125, has become available. However, blood tests by themselves can be inconclusive, and other methods should be used to confirm the diagnosis.

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