Kidney, or renal, cancer is a type of cancer that starts in the kidneys. These organs, positioned on the sides of the abdomen, have the responsibility of filtering waste and excess water from the bloodstream and sending them out in the urine; they are shaped like beans. The most common type of kidney cancer in those of adult age is renal cell carcinoma. In children, the most common type is referred to as Wilms' tumor. It is estimated that over 50,000 people are diagnosed with renal cancer in the United States each year; that number is sure to be higher around the world.
Typically, kidney cancer develops in people who are over 40 years of age. However, it can develop in people who are much younger, and no one knows its exact cause. There are some risk factors that increase kidney cancer risk; they include smoking, obesity, high blood pressure, and years of dialysis. If someone has an abnormal Von Hippel-Lindau (VHL) gene, he is also more likely to develop this type of cancer. People exposed to asbestos and cadmium occupationally may also be more at risk. For some reason, men are diagnosed with kidney cancer more often than women.
In the early stages of the disease, a person may have kidney cancer without any obvious symptoms. In the later stages, blood in the urine is a common symptom. Back pain that lingers and is located right below the rib cage can also indicate this type of cancer, as can a lump or mass that is located in the side of the abdominal region. Other symptoms can include unexplained weight loss, fever, fatigue, and an overall feeling of malaise.
A person may experience the symptoms of kidney cancer without having cancer at all. For example, a lump could be caused by a cyst instead of a tumor. Many of the other symptoms could be caused by an infection or another type of health issue. No matter what the cause of the symptoms, however, it is best to visit a doctor right away for diagnosis and early treatment. Cancer, as well as many other conditions, is often easier to treat in its early stages.
To diagnose this type of cancer, a doctor will perform a physical exam, checking on the general health of the patient and feeling for tumors. He or she may also perform urine tests to check for blood and other signs of kidney cancer. Typically, a doctor will order laboratory blood tests to evaluate levels of certain substances, including creatinine, and see how well the kidneys are functioning. High levels of creatinine may indicate poorly functioning kidneys.
A doctor may perform an intravenous pyelogram (IVP) when attempting to diagnose cancer of the kidneys. For this, dye is injected into the patient's vein, which then travels through the body and settles in the kidneys. Thanks to the dye, a doctor can see tumors and other problems on x–rays. Other tests used in making a diagnosis are CT scans, ultrasounds, and biopsies. Surgery to remove part or all of a kidney is often used for the final word in making a diagnosis; once removed, the kidney tissue is examined with a microscope by a pathologist.
Following diagnosis, a doctor takes steps to evaluate the stage of the cancer. At stage 1, the tumor will be small and limited to the kidney; in stage 2, it will be larger but still limited to the kidney. In stage 3, the cancer will have spread to the tissue surrounding the kidney, and it may spread to the adrenal glands or lymph nodes. In stage 4, the cancer has spread to more distant parts of the body, such as other organs.