Cancers of the kidney account for less than 4% of all new cancer cases found in a single year in the United States. Still, about 15 out of every 100,000 men and women in the U.S. will be diagnosed with kidney or renal pelvis cancer in a single year. That is more than 63,000 people in 2015 alone. Fortunately, more than 72% of those diagnosed will still survive 5 years later.
Kidney and renal pelvis cancer occurs almost twice as frequently in men than in women, and is more predominant in African Americans and American Indian/Alaska Natives than in Hispanics or Caucasians. It is most frequently diagnosed in adults ages 55-64 years.
The most common type of kidney cancer in adults is renal cell carcinoma, which forms in the lining of small tubes in the kidney that filter blood and remove waste. Kidney cancer that forms in the kidney center where urine collects is known as transitional cell cancer of the renal pelvis. Wilms tumor is a specific type of renal cancer that occurs in young children.
Kidney cancer in early stages does not cause pain. It may be found when a patient has an x-ray or ultrasound for a separate symptom, such as blood in the urine; pain, pressure, or a lump in the side or back; anemia; high blood pressure; fatigue, recurrent fever with no obvious sign of infection; or in men, rapid vein enlargement clustering (varicocele) around a testicle.
Kidney cancer is relatively rare, so routine screening is not advised. However, people at increased risk for developing kidney cancer, such as those with a family history of the disease, may be advised to undergo imaging tests such as computed tomography (CT) scan to search for any signs of early stage kidney cancer. Blood and urine tests may help suggest kidney cancer, but a biopsy, or removal of tissue for examination under a microscope by a pathologist, is required to confirm a diagnosis.
Imaging tests that can help measure the size and location of kidney tumors include standard x-rays, x-rays with a dye medium that highlights the renal area, or intravenous pyelogram (IVP)s, bone scans, CT scans, and contrast magnetic resonance imaging (MRI) scans. For renal pelvic cancer, cystoscopy or nephro-ureteroscopy may be helpful in removing cell samples or very small tumors.
Surgery to remove tumors may be the only treatment required for kidney cancer. A partial nephrectomy removes a tumor from the kidney but preserves kidney function. Radical nephrectomy removes the entire kidney and surrounding tissue. If nearby lymph nodes are also removed, the procedure is a radical nephrectomy with lymph node dissection. If cancer has spread to an adrenal gland, an adrenalectomy (removal of the adrenal gland and parts of the related blood vessels) is also performed. In some cases, robotic-assisted surgery or laparoscopic surgery (making several small incisions through the abdomen) may result in reduced post-operative pain and shorter healing times.
Radiofrequency ablation procedures insert a needle with an electrical current directly into a kidney tumor to destroy cancer cells. During cryosurgery, a physician uses CT or ultrasound for guidance to insert a metal probe through a small incision to freeze cancer cells.
Radiation therapy is rarely used as a first-line treatment for kidney cancer because of the potential damage that can occur to healthy kidney tissue. It is more likely to be explored if surgery is not an option, or to relieve symptoms of kidney cancer that has spread to bone or brain tissue. External beam radiation may cause skin irritation, fatigue, and diarrhea. Internal radiation therapy using implanted radioactive seeds may also cause bleeding, infection, or risk of injury to nearby healthy tissue.
Chemotherapy for kidney cancer may be given on a specific schedule orally or through the bloodstream. Newer drugs, such as a combination of fluorouracil, gemcitabine, and capecitabine, may temporarily shrink tumors, but kidney cancer is often resistant to chemotherapy. Wilms tumor and transitional cell carcinoma are more likely to respond to chemotherapy than other types of kidney cancer. Side effects during treatment may include fatigue, nausea, vomiting, risk of infection, hair loss, loss of appetite, and diarrhea.
Immunotherapy, or biologic therapy, boosts the body’s natural defenses to fight cancer and has been shown effective in treating some kidney cancers. Interleukin-2 is a special hormone called a cytokine, which is produced by white blood cells and helps destroy cancer cells. It is sometimes used to treat advanced kidney cancer, but can only be administered in high doses by experts in a clinical setting because of its potential for serious side effects. Alpha-interferon is another type of immunotherapy used to treat kidney cancer that has spread, or metastasized. Immunotherapy may be combined with chemotherapy.
Targeted therapy identifies specific genes, proteins, or tissue environments that promote cancer growth and survival, and blocks those targets to inhibit the growth and spread of cancer cells. Drugs that stop or slow cancer growth by “starving” the tumor by stopping angiogenesis, the creation of new blood vessels, are called anti-angiogenesis therapies. Clear cell kidney cancer has been associated with the vascular endothelial growth factor (VEGF) protein. Tyrosine kinase inhibitors (TKIs) are anti-angiogenesis drugs that help block the VEGF protein, which promotes development of new blood vessels. Other anti-angiogenesis drugs have shown promise for metastatic renal carcinoma and other types of kidney cancers.
Clinical trials are currently exploring immunotherapy approaches using cancer vaccines to boost the immune system as well as checkpoint inhibitors that use antibodies to stimulate molecules found on the surface of immune cells that are programmed to destroy cancer cells. Other ongoing studies are looking at better ways to diagnose and treat kidney cancers at every stage.
A 2015 study in theJournal of the American Medical Association Oncologyshowed that measuring protein levels in urine samples may help doctors identify the disease before it has spread. The kidney cancer-specific biomarkers aquaporin-1 and perlipin-2 combined were more than 95% accurate in detecting early-stage kidney cancers in a study of 720 patients at a St. Louis hospital. The patients required abdominal CT scans but were not suspected of having kidney cancer.
Find support, news, research, and more at the Kidney Cancer Association, an international charity created to eradicate death and suffering from renal cancers.