Kidney cancer

Definition

Kidney cancer is a disease in which the cells in certain tissues of the kidney start to grow uncontrollably and form tumors. Renal cell carcinoma occurs in the cells lining the kidneys (epithelial cells) and is the most common type of kidney cancer. About

ninety percent of all kidney tumors are renal cell carcinomas.

Description

The kidneys are a pair of organs about the size of a fist and shaped like kidney beans that lie on either side of the spine just above the waist. Inside each kidney are tiny tubes (tubules) that filter and clean the

blood, taking out the waste products and making urine. The urine made by the kidney passes through a tube called the ureter into the bladder. Urine is held in the bladder until it is discharged from the body. Renal cell carcinoma (RCC) generally develops in the lining of the tubules that filter and clean the blood. Cancer that develops in the central portion of the kidney (where the urine is collected and drained into the ureters) is known as transitional cell carcinoma of the renal pelvis. Transitional cell cancer is similar to bladder cancer .

Demographics

Kidney cancer accounts for approximately 2–3% of all cancers. Newly diagnosed cases of RCC have increased by about two percent per year for the past sixty-five years; the cause of the increase is not known. According to the American Cancer Society, 51,190 Americans were diagnosed with kidney cancer in 2007, and approximately 12,890 died from the disease.

Kidney cancer occurs most often in men over the age of 40 and is uncommon in people under the age of 45. The median age of diagnosis is 65. The male to female ratio is about 3:2. The lifetime risk of developing kidney cancer is 1 in 75.

Causes and symptoms

The causes of kidney cancer are unknown, but there are many risk factors associated with kidney cancer. The risk factors listed from greatest to smallest include:

• von Hippel-Lindau disease (100)
• chronic dialysis (32)
• obesity (3.6)
• tobacco use (2.3)
• first-degree relative with kidney cancer (1.6)
• hypertension (1.4)
• occupational exposure to dry cleaning solvents (1.4)
• diuretics (non-hypertension use) (1.3)
• trichloroethylene exposure (1.0)
• heavy phenacetin use (1.1–6.0)
• polycystic kidney disease (0.8–2.0)
• cadmium exposure (1.0–3.9)
• arsenic exposure (1.6)
• asbestos (1.1–1.8)

The most common symptom of kidney cancer is blood in the urine (hematuria). Other symptoms include painful urination, pain in the lower back or on the sides, abdominal pain, a lump or hard mass that can be felt in the kidney area, unexplained weight loss , fever, weakness, fatigue, and high blood pressure . Some individuals may also experience swelling of the ankles and legs.

Diagnosis

A diagnostic examination for kidney cancer includes taking a thorough medical history and making a complete physical examination in which the doctor probes (palpate) the abdomen for lumps. Urinalysis, a urine test, is usually one of the first tests to be done to look for blood and other substances in the urine. Sometimes a urine cytology test is ordered to look for cancer cells in the urine. Blood tests are ordered to check for changes in blood chemistry caused by substances released by the tumor. Laboratory tests can show abnormal levels of iron in the blood. Either a low red blood cell count (anemia ) or a high red blood cell count (erythrocytosis) may accompany kidney cancer. Occasionally, patients have high calcium levels.

If the doctor suspects kidney cancer, an intravenous pyelogram (also called an IVP or intravenous urography) may be ordered. An IVP is an x-ray test in which a dye is injected into a vein in the arm. The dye travels through the body, and when it is concentrated in the urine to be discharged, it outlines the kidneys, ureters, and the urinary bladder. On an x-ray image, the dye reveals any abnormalities of the urinary tract. The IVP may miss small kidney cancers.

Renal ultrasound is a diagnostic test in which sound waves are used to form an image of the kidneys. Ultrasound is a painless and non-invasive procedure used to detect even very small kidney tumors. Imaging tests such as computed tomography (CT) scans and magnetic resonance imaging (MRI) can be used to evaluate the kidneys and the surrounding organs. These tests check whether the tumor has spread outside the kidney to other organs in the abdomen. If the patient complains of bone pain, a special x ray called a bone scan may be ordered to rule out spread to the bones. A chest x ray may be taken to rule out spread to the lungs.

A kidney biopsy is used to positively confirm the diagnosis of kidney cancer. During this procedure, a small piece of tissue is removed from the tumor and examined under a microscope. The biopsy provides information about the type of tumor, the cells involved, and the aggressiveness of the tumor (tumor stage).

Treatment

Each person's treatment is different and depends on several factors. The location, size, and extent of the tumor have to be considered in addition to the patient's age, general health, and medical history.

Staging

The American Joint Committee on Cancer (AJCC) staging system for kidney cancer uses Roman numerals I through IV to describe and define the extent of the cancer. The lower the number, the less the cancer has spread. A higher number usually means a more serious cancer. Stages I through III are usually referred to as localized stages of kidney cancer while Stage IV indicates a kidney cancer that has metastasized or recurred. Staging guidelines for kidney cancer are as follows:

• Stage I: Primary tumor is 7 cm (2.75 in) or less in greatest dimension and is limited to the kidney, with no lymph node involvement.
• Stage II: Primary tumor is larger than 7 cm (2.75 in) in greatest dimension and is limited to the kidney, with no lymph node involvement.
• Stage III: Primary tumor may extend into major veins or invade adrenal glands or perinephric tissues, but not beyond Gerota's fascia. There may be metastasis (spreading of cancer cells) in a single lymph node.
• Stage IV: Primary tumor invades beyond Gerota's fascia. Metastasis may be to more than one lymph node. Possible metastasis to distant structures in the body.

The primary treatment for kidney cancer that has not spread to other parts of the body, a Stage I, II, or III tumor, is surgical removal of the diseased kidney (nephrectomy). Most often, the cancer affects only one kidney, and the patient can function with the remaining kidney. Two types of surgical procedure are used. Radical nephrectomy removes the entire kidney and the surrounding tissue. Sometimes, the lymph nodes surrounding the kidney are also removed. Partial nephrectomy removes only part of the kidney along with the tumor. This procedure is used either when the tumor is very small or when it is not practical to remove the entire kidney. It is not practical to remove a kidney when the patient has only one kidney or when both kidneys have tumors. There is a small (5%) chance of missing some of the cancer.

Nephrectomy can be useful for Stage IV cancers, but alternative surgical procedures such as transarterial angioinfarction may be used.

The rapid development and widespread use of laparoscopic techniques has made it possible for surgeons to remove small tumors while sparing the rest of the kidney. Most tumors removed by laparoscopy are 1.6 in (4 cm) in size or smaller. Laparoscopy allows the surgeon to remove small tumors with cryoablation (destroying the tumor by freezing it) rather than cutting. Some elderly or infirm patients with small tumors may be offered the options of surveillance (watching and waiting to see if the tumor becomes larger or causes more distress prior to treatment) or energy techniques such as cryoablation or radio-frequency ablation (using heat from high-energy radio waves to destroy cancer cells).

Radiation therapy, which consists of exposing the cancer cells to high-energy gamma rays from an external source, generally destroys cancer cells with minimal damage to the normal tissue. Side effects are nausea, fatigue, and stomach upsets. These symptoms disappear when the treatment is over. In kidney cancer, radiation therapy has been shown to alleviate pain and bleeding, especially when the cancer is inoperable. However, because it has not proven useful in destroying the kidney cancer cells, radiation therapy is not used very often as a treatment for cancer or as a routine adjuvant to nephrectomy. Radiotherapy is used to manage metastatic kidney cancer.

Treatment of kidney cancer with anticancer drugs (chemotherapy ) has not produced good results. New drugs and new combinations of drugs continue to be tested in clinical trials. New drugs such as sunitinib malate, sorafenib, and temsirolimus have been recommended for use in some patients with metastatic or relapsed kidney cancer.

Immunologic therapy (or immunotherapy), a form of treatment in which the body's immune system is harnessed to help fight the cancer, is a new mode of therapy being tested for kidney cancer. Clinical trials with substances produced by the immune cells (aldesleukin and interferon) show some promise in destroying kidney cancer cells. A monoclonal antibody, bevacizumab, in combination with interferon has been recommended for use in patients with relapsed or metastatic kidney cancer that cannot be treated surgically. These substances have been approved for use but they can be very toxic and produce severe side effects. The benefits derived from the treatment must be weighed carefully against the side effects in each case. Immunotherapy is a promising systemic therapy for metastatic kidney cancer.

Clinical trials

As of 2008, the National Cancer Institute (NCI) listed over 250 clinical trials in place across the United States studying new types of radiation therapy and chemotherapy, new drugs and drug combinations, biological therapies, ways of combining various types of treatment for kidney cancer, side effect reduction, and improving quality of life.

Alternative and complementary therapies

There are several healing philosophies, approaches, and therapies that may be used as supplemental or instead of traditional treatments. Alternative or complementary therapies have varying effectiveness in boosting the immune system and/or treating a tumor. The efficacy of each treatment varies from person to person. None of the treatments have demonstrated safety or effectiveness on a consistent basis. Patients should research such treatments for any potential dangers (laetrile, for example, has caused death due to cyanide poisoning) and notify their physician before taking them.

• 714-X
• antineoplastons
• Cancell
• cartilage (bovine and shark)
• coenzyme Q10
• Gerson therapy
• Gonzalez Protocol
• hydrazine sulfate
• immuno-augmentative therapy
• Laetrile
• mistletoe

Prognosis

Because kidney cancer is often caught early and sometimes progresses slowly, the chances of a surgical cure are good. It is one of the few cancers for which there are well-documented cases of spontaneous remission without therapy. According to the National Comprehensive Cancer Centers Network (NCCN) 2008 Practice Guidelines for Kidney Cancer the estimated five year survival rates for RCC by stage are:

• 96% for patients diagnosed with Stage I renal cell cancer
• 82% for Stage II patients
• 64% for patients presenting in Stage III
• 23% for patients in Stage IV

KEY TERMS

Bone scan —An x-ray study in which patients are given an intravenous injection of a small amount of a radioactive material that travels in the blood. When it reaches the bones, it can be detected by x ray to make a picture of their internal structure.

Chemotherapy —Treatment with anticancer drugs.

Cryoablation —A technique for removing tissue by destroying it with extreme cold.

Hematuria —Blood in the urine.

Immunotherapy —Treatment of cancer by stimulating the body's immune defense system.

Intravenous pyelogram (IVP) —A procedure in which a dye is injected into a vein in the arm. The dye travels through the body and concentrates in the urine to be discharged. It outlines the kidneys, ureters, and the urinary bladder. An x-ray image is then made and any abnormalities of the urinary tract are revealed.

Monoclonal antibody —A type of protein made in the laboratory that can locate and adhere to substances in the body and on the surface of cancer cells.

Nephrectomy —A medical procedure in which the kidney is surgically removed.

Primary tumor —A cancer's origin or initial growth.

Following surgery, about 20–30% of patients with localized tumors experience a relapse of the cancer. The most frequent time of relapse after surgery is within one to two years after surgery with most relapses occurring within three years. The longer the patient goes without relapsing after the initial diagnosis and treatment of kidney cancer, the better the prognosis.

Prevention

The exact cause of kidney cancer is not known, so it is not possible to prevent all cases. A strong association between kidney cancer and tobacco has been shown, so avoiding tobacco is the best way to lower one's risk of developing this cancer. Using care when working with cancer-causing agents such as asbestos and cadmium and eating a well-balanced diet including fruits and vegetables may help prevent kidney cancer.

QUESTIONS TO ASK YOUR DOCTOR

• What type of kidney cancer do I have?
• Has my cancer spread beyond my kidneys?
• What type of treatment(s) will I be receiving for my cancer?
• How long will my treatments last?
• How effective do you think the treatments will be?
• Do you think my cancer will return after treatment?
• What new treatments are being studied in clinical trials?
• What side effects can I expect as a result of my treatment?
• What is my prognosis or how long can I expect to live after treatment?
• What do I need to do to prepare for the treatment?
• What kind of follow-up will I need and for how long?

Caregiver concerns

Side effects of treatment, as well as nutrition , emotional well-being, and other complications, are all parts of coping with cancer. Pain, which may be treated by morphine or similar potent drugs, can be a major concern for people with advanced kidney cancer. There are many possible side effects for cancer treatment including:

• constipation
• delirium
• fatigue
• fever, chills, sweats
• nausea and vomiting
• mouth sores, dry mouth, bleeding gums
• pruritus (itching)
• sexual dysfunction
• sleep disorders

Anxiety, depression , loss, post-traumatic stress disorder, sexual dysfunction , and substance abuse are all possible emotional side-effects. Nutrition and eating before, during, and after a treatment can be of concern. Other complications of coping with cancer include fever and pain.

Resources

BOOKS

Beers, Mark H., MD, and Robert Berkow, MD, editors. “Renal Cell Carcinoma (Hypernephroma; Adenocarcinoma of the Kidney).” Section 17, Chapter 233. In The Merck Manual of Diagnosis and Therapy. Whitehouse Station, NJ: Merck Research Laboratories, 2002.

PERIODICALS

Brauch, H., G. Weirich, B. Klein, et al. “VHL Mutations in Renal Cell Cancer: Does Occupational Exposure to Trichloroethylene Make a Difference?” Toxicology Letters 151 (June 15, 2004): 301–10.

Dutcher, J. P. “Immunotherapy: Are We Making a Difference?” Current Opinion in Urology September 2000:435–9.

Godley, P. A., and K. I. Ataga. “Renal Cell Carcinoma.” Current Opinion in Oncology May 2000: 260–4.

Griffiths, T. R., and J. K. Mellon. “Evolving Immunotherapeutic Strategies in Bladder and Renal Cancer.” Postgraduate Medical Journal 80 (June 2004): 320–27.

Jennens, R. R., M. A. Rosenthal, G. J. Lindeman, and M. Michael. “Complete Radiological and Metabolic Response of Metastatic Renal Cell Carcinoma to SU5416 (Semaxanib) in a Patient with Probable von Hippel-Lindau Syndrome.” Urologic Oncology 22 (May-June 2004): 193–96.

Lam, J. S., O. Svarts, and A. J. Pantuck. “Changing Concepts in the Surgical Management of Renal Cell Carcinoma.” European Urology 45 (June 2004): 692–705.

Lotan, Y., D. A. Duchene, J. A. Cadeddu, et al. “Changing Management of Organ-Confined Renal Masses.” Journal of Endourology 18 (April 2004): 263–68.

Moon, T. D., F. T. Lee, Jr., S. P. Hedican, et al. “Lapa-roscopicCryoablation under Sonographic Guidance for the Treatment of Small Renal Tumors.” Journal of Endourology 18 (June 2004): 436–40.

ORGANIZATIONS

American Cancer Society (National Headquarters). 1599 Clifton Rd. NE, Atlanta, GA 30329. (800) 227-2345. http://www.cancer.org.

American Urological Association Foundation. 1000 Corporate Blvd., Linthicum, MD 21090. (866) 746-4282. http://www.auafoundation.org/auafhome.asp.

Cancer Research Institute (National Headquarters). 681 Fifth Ave., New York, NY 10022. (800) 992-2623. http://www.cancerresearch.org.

Kidney Cancer Association. 1234 Sherman Ave., Suite 203, Evanston, IL 60202-1375. (800) 850-9132. http://www.kidneycancerassociation.org.

National Cancer Institute (NCI). 9000 Rockville Pike, Building 31, Room 10A16, Bethesda, MD 20892. (800) 422-6237. http://www.nci.nih.gov.

National Kidney Foundation. 30 East 33rd St., New York, NY 10016. (800) 622-9010. http://www.kidney.org.

OTHER

Cancer Facts & Figures 2007. American Cancer Society (ACS). http://www.cancer.org/docroot/stt/stt_0.asp.

What is Kidney Cancer? American Cancer Society (ACS). November 6, 2007 [cited March 22, 2008]. http://www.cancer.org/docroot/CRI/content/CRI_2_2_1X_What_is_kidney_cancer_22.asp.

NCCN Practice Guidelines in Oncology-v.1.2008, Kidney Cancer. National Comprehensive Cancer Centers Network (NCCN). September 4, 2007 [cited March 22, 2008]. http://www.nccn.org/professionals/physician_gls/PDF/Kidney.pdf.

Lata Cherath Ph.D.