What is a kidney tumor?

The terms "mass", "lesion", and "tumor" are often used interchangeably to describe an abnormal growth within the kidney or any other organs. These abnormal lesions may be benign (non-cancerous), malignant (cancerous), or indeterminate.

The most common lesion is a fluid-filled structure called a cyst. There are simple cysts which have a typical thin-walled appearance on imaging studies. They may get smaller or larger but do not progress to cancer and usually require no follow-up or treatment. Other cysts may be classified as complex cysts and are often followed be serial imaging studies or removed by surgery.

Solid-appearing tumors can be benign, but are cancerous more than 90 percent of the time. These tumors are often surgically removed. The most common kidney cancer is renal cell carcinoma.

How common is kidney cancer?

The true incidence of kidney cancer is not really known since most tumors do not cause any worrisome symptoms early on. We do know that approximately 30,000 Americans are diagnosed each year and nearly 12,000 die of this disease. Some patients will get diagnosed when they are evaluated for blood in the urine or for flank pain. Others are diagnosed as incidental findings when they get evaluated for gallstones or other vague abdominal symptoms and unrelated problems.

If found early, the survival rate for patients with kidney cancer ranges from 80 to 100 percent.

What risk factors are associated with kidney cancer?

Most cases of kidney cancer occur sporadically. However, there seems to be a higher risk in certain groups including those with polycystic kidney disease, von Hippel Lindau disease, and tuberous sclerosis. Other higher risk groups are smokers, patients with kidney failure on dialysis, and those with exposure to asbestos, blast furnaces and ovens used in iron/steel manufacturing.

What are the symptoms for kidney cancer?

Many kidney tumors do not produce symptoms. Bothersome symptoms at the time of diagnosis often suggest more advanced stage of disease. These symptoms include pain (in the flank, abdomen or back) or blood in the urine (microscopic or visible blood), which can occur as the cancerous mass compress, stretch or invade structures near the kidney. Distant spread of this cancer to other parts of the body can produce symptoms such as shortness of breath or coughing up blood (lung involvement), bone pain or fracture (bone involvement), and neurologic symptoms (brain involvement). Up to 30 percent of patients will appear ill, with weight loss, loss of appetite, fever, sweats, and high blood pressure. These patients will also show low red blood cell count (anemia), high calcium level in the blood, and abnormal liver function tests.

How is kidney cancer diagnosed?

Unfortunately, there are no blood or urine tests that can directly detect the presence of kidney cancer.

As mentioned above, diagnosis by incidental finding is common. Patients who present with visible blood and patients who have detectable blood cells on urinalysis are diagnosed by imaging studies (most often ultrasound or CT scan). Others are diagnosed when they get imaging studies for pain (flank, abdominal, or back) or for evaluation of unexplained illnesses (with weight loss, fever, etc…).

How is kidney cancer staged before treatment?

Staging involves gathering information regarding the extent of the cancer at the time of diagnosis. Local involvement (kidney tumor and adjacent organs/structures including lymph node) is usually assessed by CT scan. Kidney cancer also has the tendency to grow into the kidney vein and connecting blood vessels (such as the vena cava). A chest x-ray is usually adequate for asymptomatic tumors to assess for distant spread. Bone scan and other studies are reserved for patients presenting with specific symptoms.

What is the primary treatment when a tumor is confined to the kidney?

Surgery to remove the kidney or the part involved with tumor is the primary treatment. More recently, different energy sources (freezing, heat, radiofrequency) have been used to destroy the tumor while leaving the kidney in the body. The long term result in terms of tumor or cancer control is not well known with these new approaches. Chemotherapy and radiation therapy have not been effective at the primary tumor site.

What are the different techniques of kidney cancer surgery?

Open Nephrectomy: traditional open surgery is performed through a flank or abdominal incision, typically 10 to 20 inches in length and may include removal of a rib. Radical surgery is complete removal of the kidney as well as the adrenal gland sitting above it if necessary. Partial nephrectomy is now considered standard treatment if the tumor size is relatively small (ideally less than 4 centimeters) and if it is technically feasible.

Laparoscopic Nephrectomy: this relatively new technique is performed using telescopes that are inserted into the abdominal cavity through small "key hole" incisions, with a slightly longer incision made to remove the intact kidney. Current data indicate that open and laparoscopic procedures have similar complication rates and provide equally effective cancer treatment for patients with tumors that are confined to the kidney. Compared to open surgery, patients who are successfully treated with laparoscopy enjoy shorter hospitalization time, shorter overall recovery time, and quicker return to regular activity. However, not all patients are good candidates for laparoscopic surgery. Open surgery is still preferred in patients with larger tumors and tumors with vein involvement, patients with extensive history of prior abdominal surgery, and patients with severe scarring around the kidney from prior surgery and/or infection.

Tumor Ablation: this technique involves destruction of the tumor without removing it or without removing the kidney containing the tumor. The different destructive energy sources include cryotherapy (freezing), radiofrequency, high-intensity ultrasound, and laser. Currently, this method is more commonly used in elderly patients or in patients whose health conditions limit their tolerability to more extensive surgery.

What are the treatment options for tumors that invade the renal vein or vena cava?

When the tumor invades the renal (kidney) vein or vena cava, open surgery is recommended to remove the affected kidney and to extract the tumor from the veins. These cases are often performed with the assistance of a vascular surgeon.

What are the treatment options for tumors that have spread to other organs or to other parts of the body?

Currently, there is no consensus for treatment of metastatic kidney cancer. There have been several approaches including nephrectomy followed by chemotherapy or immunotherapy, initial chemotherapy or immunotherapy followed by surgery, surgery to procure the tumor cells for vaccine development against the tumor, and radiation. Unfortunately, the success rates have been poor. Enrollment into clinical trials studying for better therapy is appropriate for interested patients.

What can I expect after treatment for kidney cancer?

Routine life-long follow-up is necessary for all patients after surgical treatment for kidney cancer. Periodic physical examination, blood tests and x-rays are included. Your doctor will determine the necessary tests and their timing based on your particular situation.

Frequently asked questions:

Should I have a biopsy of the tumor?

For kidney tumors, biopsy is usually not indicated because more than 90 percent of solid tumors are cancer and negative biopsies can be false-negatives. The safest approach is to consider all solid kidney tumors cancerous until proven otherwise.

Do I need a lymph node dissection?

Lymph node dissection (surgical removal of lymph nodes) is usually unnecessary in patients with localized tumors and normal size lymph nodes. For patients with suspicious cancer involvement in the lymph nodes, removal of these involved nodes will not necessarily affect the overall prognosis.

Can I live a normal life with one kidney?

Most patients can live a normal life with a single, adequately functioning kidney.

After kidney surgery, what can I do to protect my kidney function?

In patients with only one kidney, it may be prudent to avoid contact sports and limited contact sports (baseball, gymnastics, skiing) to prevent traumatic injury to the remaining kidney. Chronic use of certain medications (ibuprofen etc...) can cause kidney damage in rare situations. Thus, it is best to use these substances only when necessary.

High blood pressure and diabetes are the two main causes of kidney failure in the U.S. The risks for these two conditions include obesity, poor diet, and lack of physical exercice.

What can I do to prevent the recurrence of kidney cancer?

There are no proven ways to prevent recurrence of kidney cancer; however, it would not hurt to stop smoking!

Glossary Terms

abdomen - also referred to as the belly or stomach;
ablation - to remove or destroy unwanted tissue such as a tumor;
adrenal gland - one of a pair of small glands, each of which sits on top of one of the kidneys. These glands produce hormones that help control heart rate, blood pressure, the way the body uses food and other vital functions; it also produces adrenaline;
adrenaline - vital hormone secreted by the adrenal gland;
artery - blood vessel that carries blood from the heart to various parts of the body;
benign - not cancerous, not malignant;
dialysis - an artificial replacement for the kidneys used to remove waste products from the blood and excess fluid from the body;
flank - the area on the side of the body between the rib and hip;
immunotherapy - medical treatment aimed to stimulate or restore the ability of the immune system to fight infection and disease (including cancer);
metastasis - the spreading of a cancerous tumor to another part of the body;
nephrectomy (-ies) - surgical removal of a kidney;
neurologic - pertaining to the nervous system;
partial nephrectomy - surgery to remove the part of the kidney involved with tumor;
radical nephrectomy - complete removal of a kidney involved with tumor;
renal vein - blood vessel which returns blood from the kidneys to the blood system;
vena cava - large vein through which blood is carried to the heart;

*  This information is not intended to substitute for a consultation with a urologist. It is offered to educate patients on the basis of urological conditions in order to get the most out of their office visits and consultations. Please see our web page disclaimer for addition information.

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