Kidney Cancer Facts

The American Cancer Society estimates that more than 58,240 people were diagnosed with kidney cancer in 2010. In the 1980s, up to 80% of kidney cancers were in advanced stages when they were diagnosed. Today, thanks to more advanced detection methods, only about 40% of cases are advanced at diagnosis.

You have two kidneys, one on each side of the back above the waist. Kidneys filter blood, and the waste is carried in the urine, which is produced by microscopic tubules. Urine flows into the ureter tubes and down into the bladder. Cancer arises from the microscopic tubules inside the kidney. Although kidney cancer usually grows as a single mass within the kidney, a kidney may contain more than one tumor, or tumors may be found in both kidneys.

Surgery offers the highest chance for successful treatment when kidney cancer has not spread. Once the cancer has spread beyond the kidney, the chance for successful treatment becomes much lower. Since 2006, new-generation drugs called targeted therapies have become available to control the cancer more successfully than prior medications.

Kidney Cancer Types

Renal cell carcinoma (cancer) (RCC) is the most prevalent form of kidney cancer. Types of RCC include clear cell, papillary, chromophobe and collecting duct carcinomas. Clear cell carcinoma accounts for 80% of all RCC cases, and most treatments are focused on this type.

Wilms’ tumor is a childhood cancer, responsible for 95% of pediatric kidney cancer cases. Learn more about Wilms’ tumor.

Urothelial cancer of the kidney pelvis and ureter: Cancer of the urinary tract that occurs in the kidney or ureter is called urothelial carcinoma. It is not considered kidney cancer, although it is frequently called that in error.

Kidney cancer is cancer that originates in the kidneys. Your kidneys are two bean-shaped organs, each about the size of your fist. They’re located behind your abdominal organs, with one kidney on each side of your spine.

In adults, the most common type of kidney cancer is renal cell carcinoma. Other less common types of kidney cancer can occur. Young children are more likely to develop a kind of kidney cancer called Wilms’ tumor.

The incidence of kidney cancer seems to be increasing. One reason for this may be the fact that imaging techniques such as computerized tomography (CT) scan are being used more often. These tests may lead to the accidental discovery of more kidney cancers.

Renal cell carcinoma (RCC) is the most common renal cancer. Symptoms can include hematuria, flank pain, a palpable mass, and FUO. However, symptoms are often absent, so the diagnosis is usually suspected based on incidental findings. Diagnosis is confirmed by CT or MRI and occasionally by biopsy. Treatment is with surgery for early disease and targeted therapy, an experimental protocol, or palliative therapy for advanced disease.

RCC, an adenocarcinoma, accounts for 90 to 95% of primary malignant renal tumors. Less common primary renal tumors include transitional cell carcinoma, Wilms tumor (most often in children - Wilms’ Tumor), and sarcoma.

In the US, about 65,000 cases of RCC and pelvic tumors and 13,000 deaths occur each year. RCC occurs slightly more often in men (male:female incidence is about 3:2). People affected are usually between 50 and 70 yr. Risk factors include the following:

  Smoking, which doubles the risk (in 20 to 30% of patients)
  Obesity
  Excess use of phenacetin
  Acquired cystic kidney disease in dialysis patients
  Exposure to certain radiopaque dyes, asbestos, cadmium, and leather tanning and petroleum products
  Some familial syndromes, particularly von Hippel - Lindau disease

RCC can trigger thrombus formation in the renal vein, which occasionally propagates into the vena cava. Tumor invasion of the vein wall is uncommon. RCC metastasizes most often to the lymph nodes, lungs, adrenal glands, liver, brain, and bone.