Kidney cancer develops when abnormal cells form in the kidney and start reproducing quickly. These abnormal cells eventually form a mass, or tumor, that grows into and destroys healthy kidney tissue. 
Cancer that starts in the kidneys may also invade nearby organs, such as the liver, colon or pancreas. Cells sometimes break away from the original tumor and spread to farther parts of the body, usually the bones or lungs. 
Types of kidney cancer 
There are several types of kidney cancer, according to the <a href="[BASEDOMAIN]/healthinfo/bouncelink.aspx?shortcut=cancersoc" target="_blank">American Cancer Society</a> (ACS). 
Renal cell carcinoma is the most common type. About 90% of all kidney cancers are renal cell carcinomas. 
Transitional cell carcinoma occurs in the kidney area that leads to the bladder. 
Wilms tumor is a kidney cancer that develops in children. 
Renal sarcoma is a rare form of kidney cancer that starts in the kidney's blood vessels or connective tissue. 
Symptoms 
Kidney cancer is often found when symptoms develop. The symptoms can include: 
<ul>
 <li>Blood in the urine. </li>
 <li>Pain in the side or lower back. </li>
 <li>A lump or mass in the side or abdomen. </li>
 <li>Fatigue. </li>
 <li>Sudden weight loss for no apparent reason. </li>
 <li>Fever.</li>
 <li>Anemia.</li>
</ul>
These symptoms could be caused by a less serious condition, but they're worth checking out. Early treatment is always best. 
Risk factors 
The cause of kidney cancer remains unknown, but a few risk factors have been identified. According to the ACS, the <a href="[BASEDOMAIN]/healthinfo/bouncelink.aspx?shortcut=nci" target="_blank">National Cancer Institute</a> and the <a href="[BASEDOMAIN]/healthinfo/bouncelink.aspx?shortcut=Kidney" target="_blank">National Kidney Foundation</a>, risk factors may include: 
<ul>
 <li>Smoking cigarettes. </li>
 <li>Advanced kidney disease, especially if it requires dialysis, a treatment that removes wastes from the blood. People need dialysis when their kidneys don't function well enough to do this work. </li>
 <li>Von Hippel-Lindau (VHL) syndrome. This rare disease runs in families. </li>
 <li>Exposure to asbestos, cadmium, trichloroethylene or certain other chemicals at work. </li>
 <li>Family history of kidney cancer. </li>
 <li>High blood pressure. </li>
 <li>Obesity. </li>
 <li>Gender. Men get this cancer more often than women. </li>
 <li>Race. Black people are slightly more likely than white people to develop kidney cancer. </li>
</ul>
Treatment 
Surgery is the most common treatment for kidney cancer. This may involve removing part or all of the kidney and sometimes nearby tissues and glands. Other treatment options include: 
<ul>
 <li>Arterial embolization, which means cutting off the blood supply to the tumor by blocking the artery that leads to the kidney. </li>
 <li>Chemotherapy, which means using medicines to destroy or damage cancer cells. </li>
 <li>Radiation therapy, which means using high-energy rays to destroy cancer cells. </li>
 <li>Immunotherapy, which means using medicines that boost the immune system's ability to identify and destroy cancer cells. </li>
 <li>Targeted therapies or medicines that target specific parts of cancer cells or specific steps in the process of tumor growth. </li>
 <li>Pain relievers to ease the symptoms of advanced cancer. </li>
</ul>
Reviewed 3/22/2024
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Sources
<ul>
 <li>American Cancer Society. "Kidney Cancer Signs and Symptoms." <a target="_blank" href="https://www.cancer.org/cancer/kidney-cancer/detection-diagnosis-staging/signs-and-symptoms.html">https://www.cancer.org/cancer/kidney-cancer/detection-diagnosis-staging/signs-and-symptoms.html</a>.</li>
 <li>American Cancer Society. "Risk Factors for Kidney Cancer." <a target="_blank" href="https://www.cancer.org/cancer/kidney-cancer/causes-risks-prevention/risk-factors.html">https://www.cancer.org/cancer/kidney-cancer/causes-risks-prevention/risk-factors.html</a>.</li>
 <li>American Cancer Society. "What Causes Kidney Cancer?" <a target="_blank" href="https://www.cancer.org/cancer/kidney-cancer/causes-risks-prevention/what-causes.html">https://www.cancer.org/cancer/kidney-cancer/causes-risks-prevention/what-causes.html</a>.</li>
 <li>American Cancer Society. "What Is Kidney Cancer?" <a target="_blank" href="https://www.cancer.org/cancer/types/kidney-cancer/about/what-is-kidney-cancer.html">https://www.cancer.org/cancer/types/kidney-cancer/about/what-is-kidney-cancer.html</a>.</li>
 <li>National Cancer Institute. "Renal Cell Cancer Treatment (PDQ)-Patient Version." <a target="_blank" href="https://www.cancer.gov/types/kidney/patient/kidney-treatment-pdq">https://www.cancer.gov/types/kidney/patient/kidney-treatment-pdq</a>.</li>
 <li>National Kidney Foundation. "5 Ways to Reduce Your Risk for Kidney Cancer." <a target="_blank" href="https://www.kidney.org/newsletter/5-ways-to-reduce-your-risk-kidney-cancer">https://www.kidney.org/newsletter/5-ways-to-reduce-your-risk-kidney-cancer</a>.</li>
</ul>
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Understanding kidney cancer

The exact cause of kidney cancer remains a mystery, but some risk factors have been identified. Several treatments can help.