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A small tumor in the kidney that may be painless and often an accidental finding on sonography.
Renal cell carcinoma (RCC) is the most common type of kidney cancer that accounts for 90% of all cases. Cancerous cells typically develop in the lining of very small filtering tubes in the kidney called tubules. Cancer cells start multiplying and grow out of control forming a tumor in one or both kidneys. Renal cell carcinoma is more common in males than in females (ratio of 3:2), and patients are typically 50-70 years old. It then spreads (metastasizes) easily to the lungs and other organs. Early diagnosis and treatment of RCC can help patients have a relatively normal lifespan.
What are the types of renal cell carcinoma?
Renal cell carcinomas are classified into three major subtypes, based on their microscopic appearance:
- Clear cell RCC: The most common type (75%) with pale or clear cells.
- Papillary RCC (15-20%): Form little finger-like projections called papillae.
- Chromophobe RCC (5%): Form clear cells that are considerably large.
The survival rate is low in clear cell renal cell carcinoma because it is usually discovered at a more advanced stage.
What are the causes and risk factors of RCC?
The exact cause of renal cell carcinoma is unknown. Research suggests that two genes on the short arm of chromosome 3 (PRC and TFE 3) may be involved in the development of RCC. Another gene, VHL, has also been linked with kidney cancer.
The following conditions may increase the risk for developing this cancer:
- Family history of the disease
- Obesity
- Smoking
- High blood pressure
- Horseshoe kidney
- Polycystic kidney disease
- Kidney failure
- Dialysis treatment
- Long-term use of immunosuppressant medications, diuretics, and painkillers
- Birt-Hogg-Dubé syndrome (a genetic disease associated with benign skin tumors and lung cysts)
- Von Hippel-Lindau disease (a hereditary disease affecting blood vessels in the eyes, brain, and other body parts)
What are the signs and symptoms of renal cell carcinoma?
Some patients with RCC do not have symptoms (asymptomatic). Sometimes, symptoms do not appear until the cancer has spread to other parts of the body, usually the lymph nodes, lungs, or the long bones.
Some signs and symptoms that may be present include:
- Blood in the urine
- Brown or rust-colored urine
- Weight loss
- Abnormal clot formation in blood vessels
- Fever
- Abdominal pain and swelling
- Back pain
- Vision abnormalities
- Elevated blood pressure
- Anemia
- Pale skin
- Liver dysfunction
- Elevated erythrocyte sedimentation rate (ESR), which is a blood test
- Swelling of the veins around a testicle (varicocele)
- Excessive hair growth in females
How is renal cell carcinoma diagnosed?
Physical examination by the doctor may reveal a mass or swelling in the abdomen.
Some diagnostic tests to confirm the presence of cancer and the stage may be advised by the doctor. They include:
- Abdominal CT scan
- Abdominal ultrasonography
- Ultrasound of the abdomen and kidney
- Renal arteriography
- Urine analysis
- Liver function tests
- Intravenous pyelogram
- Blood chemistry
- Complete blood count (CBC)
The following tests may be done to find metastasis (spread) of cancer to other parts of the body:
- Biopsy
- Chest X-ray
- Chest computed tomography (CT) scan
- Abdominal magnetic resonance imaging (MRI)
- Bone scan
- Positron emission tomography (PET) scan
Stages of renal cell carcinoma
Cancer staging is an important system to determine the spread. It ranges from:
- Stage 1: Tumors are confined to the kidney and are usually less than 7 cm in diameter.
- Stage 2: Tumor involves the fat or adrenal tissues of the kidney and greater than 7 cm in diameter.
- Stage 3: Tumors have spread to the regional kidney tissues or lymph nodes and kidney veins or vena cava.
- Stage 4: Tumors have spread outside the kidney to distant sites in the body or other organs (liver, colon, pancreas, stomach, etc.)
How is renal cell carcinoma treated?
RCC can be treated in the following ways:
- Surgery: Involves surgical removal of part or whole of the kidney (nephrectomy). This may include removal of the bladder, surrounding tissues, or lymph nodes.
- Chemotherapy: Antitumor drugs and targeted medicines that target the development of blood vessels feeding the tumor may help.
- Immunotherapy: Newer immune system medicines may help.
- Hormone treatments: May reduce the growth of the tumor in some cases.
- Ablation: Destruction of tumor cells by cryotherapy, radiofrequency, or embolization.
- Radiation therapy: This is usually done when cancer spreads to the bone or brain.
What is the life expectancy of renal cell carcinoma?
The 5-year survival rate is good for patients diagnosed with stage 1 RCC (81%) or stage 2 RCC (74%). The prognosis worsens as stages 3 and 4 develop. Diagnosis of cancer in the early stages is especially important because the treatment can begin promptly. Also, an early diagnosis can give the patient a relatively normal lifespan.