Screening and Diagnosis
When a cancerous tumor grows within the body cancer cells can break away from the primary (original) tumor and travel through the lymph or blood to other places in the body and another (secondary) tumor may form. This process is called metastasis. The secondary (metastatic) tumor is the same type of cancer as the primary tumor. For example, if kidney cancer spreads to the bones, the cancer cells in the bones are actually kidney cancer cells. The disease is metastatic kidney cancer, not bone cancer.
A number of different tests are used to make the diagnosis of kidney cancer and then determine the extent of spread of the cancer. The extent of spread is also referred to as the stage of the cancer. These tests generally involve blood tests, urine tests, and various radiology tests such as CT, MRI, or ultrasound tests. Determining the spread of the cancer is very important as it provides important information on prognosis and likelihood of treatment success.
The following tests and procedures may be used:
During Your Clinic Appointment
- Physical exam and history: An exam of the body to check general signs of health, including checking for signs of disease, such as lumps or anything else that seems unusual. A history of the patient's health habits and past illnesses and treatments will also be taken.
- Blood chemistry studies: A procedure in which a blood sample is checked to measure the amounts of certain substances released into the blood by organs and tissues in the body. An unusual (higher or lower than normal) amount of a substance can be a sign of disease in the organ or tissue that makes it.
- Urinalysis: A test to check the color of urine and its contents, such as sugar, protein, red blood cells, and white blood cells.
- Liver function test: A procedure in which a sample of blood is checked to measure the amounts of enzymes released into it by the liver. An abnormal amount of an enzyme can be a sign that cancer has spread to the liver. Certain conditions that are not cancer may also increase liver enzyme levels.
These tests are generally done of the abdomen and pelvis but may also include the chest or brain.
- Ultrasound exam: A procedure in which high-energy sound waves (ultrasound) are bounced off internal tissues or organs and make echoes. The echoes form a picture of body tissues called a sonogram.
- CT scan (CAT scan): A procedure that makes a series of detailed pictures of areas inside the body, taken from different angles. The pictures are made by a computer linked to an x-ray machine. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. This procedure is also called computed tomography, computerized tomography, or computerized axial tomography.
- MRI (magnetic resonance imaging): A procedure that uses a magnet, radio waves, and a computer to make a series of detailed pictures of areas inside the body. This procedure is also called nuclear magnetic resonance imaging (NMRI).
While all of these tests give a good representation of a possible kidney cancer, a definitive diagnosis can only be made by a pathologist who views tissue from the cancerous tumor under a microscope. This tissue can be obtained only by biopsy or surgical removal of the kidney tumor.
Once these tests are complete the cancer can be given a stage to the tumor. The following stages are used for renal cell cancer:
In stage I, the tumor is 7 centimeters or smaller and is found only in the kidney. Frequently these tumors are subdivided using the TNM system. In this system a T1a tumor is less than 4cm and a T1b tumor is 4-7cm.
In stage II, the tumor is larger than 7 centimeters and is found only in the kidney. In the TNM system this stage is referred to as a T2 tumor.
In stage III, cancer is found in the kidney and in either 1 nearby lymph node, the layer of fat around the kidney, or in the main blood vein of the kidney (renal vein).
In stage IV, cancer has spread beyond the layer of fatty tissue around the kidney, into the adrenal gland, or to distant organs (lung, liver, etc).