What is Kidney Cancer?
The kidneys are two bean-shaped organs located in the abdomen on either side of the spine. Several types of cancer can affect the kidneys.
Adenocarcinoma of the kidney is also known as renal cell carcinoma. It is the most common type of kidney cancer in adults. It starts in the part of the kidney that filters blood.
Renal pelvis carcinoma starts in the part of the kidney where urine is collected.
Wilm’s tumor is the most common type of kidney cancer in children under the age of 5.
There are other types of kidney cancer, but they are rare.
Incidence of Kidney Cancer
The National Cancer Institute projects that close to 65 thousand Americans will develop kidney cancer in 2012. There will also be more than 13 thousand deaths.
The incidence of kidney cancer is increasing, according to the Mayo Clinic. Scientists do not yet know why. However, they do know that kidney cancer is most likely to occur in older people. It is also more common in men than women.
Causes and Risk Factors
The causes of kidney cancer are unknown. Risk factors include:
- male gender
- long term dialysis
- horseshoe kidney
- polycystic kidney disease
- toxin exposure in the workplace
There are also several inherited conditions that increase a person’s risk of kidney cancer. These include Von Hipple-Lindau disease and hereditary papillary renal cell carcinoma.
Symptoms of Kidney Cancer
Symptoms of kidney cancer include:
- back pain
- abdominal pain and swelling
- flank pain
- weight loss
- pale skin
- intolerance to cold
- vision problems
- excessive hair growth (women only)
How Kidney Cancer Is Diagnosed
Diagnosis of kidney cancer requires a complete history and physical. The doctor will look for an abdominal swelling or mass. In men, the doctor may also look for an enlarged, twisted vein (varicocele) in the scrotum.
Some tests that can be used to detect kidney cancer include:
CBC (Complete Blood Count)
The kidneys produce a hormone called erythropoietin (EPO) that stimulates production of red blood cells. A CBC can reveal if the red blood cell count is high (polycythemia) or low (anemia).
Blood Chemistry Studies
Electrolytes, BUN and creatinine tell how well the kidneys are functioning.
Liver Function Tests
Elevated liver function tests may indicate that cancer has spread to the liver.
There may be blood in your urine. Signs of infection may also be present.
Ultrasound of the abdomen and kidneys: This study measures the size of the kidneys. It also reveals if the shape of the kidneys is normal. If a tumor is present, it may reveal its size and consistency.
In this test, a catheter is fed from the groin to the renal artery. A special dye is then injected into the artery. After the dye is injected, a series of X-rays are obtained. This helps doctors to see the blood supply of the kidney in detail. If a tumor is present, the blood supply to the tumor can be seen.
In this test, the lab technician will inject a special dye into a vein. The dye allows the kidneys to be seen more clearly with X-rays. This test can help doctors find a tumor or obstruction.
CT Scan (Computerized Axial Tomography) of the Abdomen
This is a non-invasive X-ray study. It allows bones, muscles, fat, organs, and blood vessels to be viewed. It can be used to find out if cancer has spread beyond the kidney.
The following tests can be used to find out if kidney cancer has spread:
- MRI of the abdomen
- bone scan
- chest X-ray
- PET scan
- chest or abdominal CT scan
Treatment of Kidney Cancer
Treatment of kidney cancer focuses on removing the tumor from the body. This is usually done through surgery. Surgery can be radical or conservative.
Radical nephrectomy is surgical removal of the kidney. The entire organ is removed, along with some adjacent tissue and lymph nodes. The adrenal gland may be removed as well. This can be done through a large incision or with a laparoscope.
Conservative nephrectomy removes only the tumor, lymph nodes, and some surrounding tissue. Part of the kidney is left behind. This is also known as nephron sparing nephrectomy.
Tumor cells can also be killed by freezing (cryosurgery), or heat (radio frequency ablation).
Metastatic kidney cancer can not be treated with surgery alone. After as much tumor is removed as possible with surgery, other treatments remain necessary. These may include immunotherapy, targeted therapy, and radiation. They can have unpleasant side effects.
Immunotherapy uses synthetic versions of immunoactive chemicals found in the body. Interferon and aldesleukin (or Proleukin) are examples of drugs used in immunotherapy.
Targeted drugs are designed to block certain abnormal signals present in kidney cancer cells. Axitinib (Inlyta), bevacizumab (Avastin), pazopanib (Votrient), sorafenib (Nexavar) and sunitinib (Sutent) are examples of targeted drugs. They help stop the formation of new blood vessels to supply nutrients to the cancer cells.
Prevention of Kidney Cancer
Some ways to reduce your risk of kidney cancer include:
- quitting smoking
- eating a balanced diet
- losing weight
- protecting yourself from chemical toxins at work
- controlling your blood pressure
Prognosis for Kidney Cancer
The prognosis of kidney cancer varies. It depends on how quickly the cancer is caught and how it responds to treatment.
In 30 percent of cases, kidney cancer has already spread to other parts of the body at the time of diagnosis. Kidney cancer can spread (metastasize) to the other kidney, but it is most likely to spread to the lungs. Metastatic cancer is harder to treat
Kidney cancer can also be complicated by high blood pressure, high blood calcium, over production of red blood cells, and problems with the liver.