Kidney Cancer

What Is Kidney Cancer

The kidneys are two organs that filter waste products from the blood and form urine, as well as secrete vital hormones for proper body functioning. Kidney cancer, also referred to as renal cancer, occurs when cancer develops in normal kidney tissue.

To better understand kidney cancer, let’s take a quick look at how the kidneys function. Our kidneys—each the size of a fist—are a pair of bean-shaped organs that are attached to the upper back part of the abdominal wall—one on either side of the spine. Above each kidney sit the adrenal glands. The main job of the kidneys is to filter the blood coming in via the renal arteries to remove excess water, salt, and waste products—which collectively become urine. Urine leaves the kidneys via long slender tubes called ureters, which connect to the bladder. Urine is stored in the bladder until you urinate (or, more colloquially, pee). The place where the ureters meet the kidneys is called the renal pelvis. The kidneys also perform several other functions—they help:

  • Control blood pressure by making a hormone called renin
  • Make sure the body has enough red blood cells by making a hormone

While our kidneys are important, it’s interesting to note that we actually need less than one complete kidney to function. Many people are living normal, healthy lives with just one kidney. Some people, however, do not have any working kidneys, and they survive with the help of dialysis, a medical procedure that uses a special machine to filer the blood much the way a real kidney would. More than 1 million cases of cancer will be diagnosed this year. Kidney cancers only comprise 3% of these new cancers. Although nearly 13,000 people died from kidney cancer in the US in 2005, it is estimated that there are more than 100,000 kidney cancer survivors living in the US currently.

According to the National Cancer Institute, there are three main forms of renal cancer:

Renal cell cancer (RCC). RCC is the most common type of renal cancer in adults—accounting for 9 out of 10 kidney cancers—and stems from the cells that comprise the kidneys themselves.  It is now understood that many subtypes of RCC exist. For example, there are the following subtypes:

  • Clear cell RCC (the most common type)—About 7 out of 10 people with RCC have this type of cancer. When seen under a microscope, the cells that make up clear cell RCC appear very pale or clear
  • Papillary RCC—About 1 in 10 RCCs are of this type, making it the second most common subtype
  • Chromophobe RCC—Accounts for about 5% of RCCs
  • Rare types of RCC include:
    • Collecting duct RCC
    • Multilocular cystic RCC
    • Medullary RCC
    • Sarcomatoid RCC
    • Mucinous tubular and spindle cell carcinoma
    • Neuroblastoma-associated RCC
    • Unclassified RCC

Wilms tumor. Wilms tumors—or nephroblastomas—are the most common type of kidney cancer found in children, and are rarely found in adults.

Transitional cell cancer. Transitional cell cancer forms from tissues comprising the renal pelvis, or part of the urine collection system of the kidney, and the ureter, which carries urine from the kidneys to the bladder. Of every 100 cancers in the kidney, about 5 to 10 are transitional cell carcinomas (TCCs), also known as urothelial carcinomas. Transitional cell carcinoma is a more rare, but potentially very aggressive type of kidney or renal cancer. About 9 out of 10 TCCs of the kidney are cured if they are found at an early stage. The chances for cure are lower if the tumor has grown into the ureter wall or main part of the kidney or if it looks more aggressive (high grade) when seen under a microscope.

Benign (non-cancerous) kidney tumors

There are also a number of benign—non-cancerous—kidney tumors, which means that they do not metastasize or spread throughout the body, but can nonetheless still grow and cause considerable trouble. Benign kidney tumors can be treated by either removing or destroying them, using many of the same treatments utilized for kidney cancers, like surgery, radiofrequency ablation, and arterial embolization. Choice of treatment  hinges on many factors, like the size of the tumor and if it is causing any symptoms, number of tumors, whether tumors are in one or both kidneys, and the person’s overall health. These are the main types of benign kidney tumors:

  • Renal adenoma. These are the most common benign kidney tumors; which often look a lot like low-grade renal cell carcinomas.
  • Oncocytoma. These benign kidney tumors sometimes grow quite large.  Similar to renal adenomas, they can sometimes be hard to tell apart from kidney cancers.
  • Angiomyolipoma. Angiomyolipomas are rare. They often develop in people with tuberous sclerosis, a genetic condition that also affects the heart, eyes, brain, lungs, and skin.

What Causes Kidney Cancer

The specific cause of kidney cancer remains unknown. However, certain risk factors associated with developing the disease have been identified. These are outlined below in the Risk Factors section.

It is known that kidney cancer, as well as all other cancers, are a disease characterized uncontrolled cellular growth. Normally, specific genes within the DNA (genetic material) of cells have functions to regulate cell division. Genes involved in cell replication, cell division, cellular growth, and cellular survival are called oncogenes, while those involved in limiting cell growth and division and induce cell death when necessary are called tumor suppressor genes (such as TP53 and RB1 genes).

When cell DNA is damaged, these genes may be altered and the oncogenes are turned on and the tumor suppressor genes are turned off. As a result, there is uncontrollable cell growth and possible cancer. While these changes to the DNA of cells are caused by the environment, changes or mutations to DNA can also be inherited. If these mutations in the DNA correspond to genes that are involved with effective and correct cell replication, a person’s risk for developing kidney cancers and other cancers may be increased.

Risk Factors For Kidney Cancer

Although the cause of kidney cancer is still largely unknown, there are some genetic conditions and environmental factors, which may contribute to the development of this disease.

According to the Mayo Clinic, risk factors for developing kidney cancer are:

  • Age. Your risk of kidney cancer increases as you age
  • Smoking. Smokers have an increased risk of kidney cancer compared to non-smokers. However, your risk decreases after you quit. Another great reason to quit smoking.
  • Obesity. In addition to all of the other damaging effects on your body, excess weight increases your risk of this disease
  • High blood pressure, or hypertension
  • Dialysis. Those receiving dialysis on a long-term basis are at an increased risk of renal cancer
  • Specific inherited conditions that increase your risk of developing kidney cancer are:
    • Von Hippel-Lindau syndrome
    • Hereditary leiomyomatosis and renal cell cancer
    • Birt-Hogg-Dube syndrome,
    • Hereditary papillary renal cancer
  • Tuberous sclerosis may also increase your risk of renal cancer.
  • Gender. Gender plays a role in the development of renal cancer as twice as many cases are found in males compared to females.


Diagnosing Kidney Cancer

A diagnosis of kidney cancer will likely start with a visit to your primary care physician, who will obtain a thorough medical history and then perform a physical examination. In addition, he or she will then utilize any of the following tools to arrive at a diagnosis:

CT scans use x-rays to generate an image, but have several advantages compared to the chest x-ray. It will show the precise location, shape, and size of masses. In order to obtain even sharper images, some patients are asked to drink or receive IV contrast. This contrast makes some tissues appear brighter, which makes the images and the structures more apparent and easier to discern. Allergies to contrast medium may cause hives, flushing, shortness of breath, and low blood pressure. If you have had a reaction to contrast before, you should inform your physician. In addition to masses (such as cancers), it can show enlarged lymph nodes, which may have cancer cells. Many patients will have CT scans of the chest, as well as the abdomen to look for cancer spread, which may involve the liver, adrenal glands, or other internal organs. The CT scan may also involve the brain to look for cancer metastasis. A CT scan may also be used to obtain biopsies of masses or cancers that lie deep within or nearby other vital structures, which is termed CT guided needle biopsy.

Magnetic resonance imaging (MRI) studies also provide detailed soft tissue “pictures.” As opposed to CT scans, which utilizes x-rays, MRIs use magnetic radio waves to generate images. MRIs are particularly useful for imaging the brain and spinal cord. Gadolinium, a contrast, is often used to produce even better MRI images.

PET scans, also known as positron emission tomography, are especially useful to look for cancer spread. This study involves injecting a special radioactive sugar (flurodeoxyglucose, or FDP) into the vein. The amount of radioactivity is very low and will not cause you harm. After the injection, a special scanner will pick up areas in your body where the sugar has accumulated. As cancer cells are very active and require a great amount of energy (sugar), the FDP will concentrate in these areas. The PET scan does not produce extremely detailed images, but rather indicates spread of cancer throughout the body.

Bone scans can also be performed to detect spread of cancer to bones. During this procedure, a radioactive dye is injected in the vein, where is it transported to areas of bone with abundant activity, which may occur in cancerous and non-cancerous states.

Simple chest x-rays or radiographs will usually be performed as it is convenient, cheap, and will reveal if the cancer has progressed to the lungs

An intravenous pyelogram, or IVP, is an x-ray test that  provides pictures of the kidneys, bladder, ureters, and urethra, and can evaluate the collecting system within the kidneys. During this procedure a specialized dye called contrast material is injected into a vein in your arm, where it is carried throughout the body, including the kidneys. X-rays are then taken at timed intervals. These images can demonstrate abnormalities within the kidneys.

Ureteroscopy is a procedure that utilizes a small camera placed through the urethra, bladder, and into the ureter to assess for areas of possible damage and cancer.

Angiography, which utilizes a specialized intravenous dye to visualize the arteries of the body, may also be used to help demonstrate the blood supply of the tumor and to help the surgeon plan his or her surgery.

If a suspicious mass is identified via the aforementioned tests, a biopsy may need to be performed to ensure proper diagnosis. During a biopsy, a small amount of tissue is removed from the suspicious mass and then assessed under the microscope. A biopsy is commonly performed as a fine needle aspiration, or FNA, which utilizes CT imaging and a long, thin needle to pierce the skin and to obtain a small tissue sample of the mass. A pathologist will then study the biopsy to determine if the mass is benign or malignant and will then identify the exact type of malignancy.


Possible lab tests used to diagnosis kidney cancer include:

  • a urinalysis (UA), which can demonstrate blood in the urine, and
  • a complete blood count, which may show increased levels of red blood cells in the presence of specific types of kidney cancer.

Symptoms of Kidney Cancer

Symptoms of renal cancer are usually absent until the disease is advanced. Unfortunately, prognosis declines as the disease progresses.

The most common symptom of renal cancer is painless bleeding in the urine, which is known as hematuria. Hematuria occurs in almost half of all patients with renal cancer . Although this is a common sign of kidney cancer, hematuria can occur in other medical conditions, such as kidney stones, or nephrolithiasis.

Other common signs and symptoms include:

  • Abdominal mass
  • Back or flank pain
  • Weight loss
  • Low blood count, or anemia
  • Tumor calcification on x-ray
  • Fever
  • High levels of calcium in the blood, also known as hypercalcemia
  • High blood counts


Prognosis refers to the likely course of a disease or ailment. To determine the prognosis of kidney cancer, many factors must be considered. For example, the age of the patient and his or her functional status, or level of functioning, also plays a vital role in prognosis. Generally, younger and higher functioning patients will do best. Further, the amount of tumor able to be removed, also known as resected, impacts prognosis. If all of the tumor is removed, prognosis improves, while if only part of the tumor is removed, prognosis will likely deteriorate. If the tumor recurs, or comes back after removal, the prognosis is worse

Generally, the earlier the cancer is detected, the better the prognosis. Unfortunately, RCC usually has very few symptoms until it has progressed considerably. As a result, 30% of RCC patients have advanced disease at the time of diagnosis. 15-25% of these patients already have metastatic, or disease that has spread from the kidneys to other areas of the body.

Also very important for prognosis is staging and grading of the cancer. Staging of a cancer is the process of classifying how far a cancer has spread, while grading determines the makeup and characteristics of the cancer’s cells. In addition to prognostic value, staging and grading can help predict what therapy is most ideal and the effectiveness of the therapy. The American Joint Committee on

Cancer (AJCC) has standardized staging system that employs the size of the tumor (T), the number of involved lymph nodes (N), and the presence of metastasis (M). Thus, it is referred to as the TNM staging system. The more advanced each of these categories, like tumor size, the higher the number that follows the letter. The size of the tumor ranges from 0-4, while the staging of involved lymph nodes varies from 0-2 and the presence of metastases is determined with 0 or 1. A combination of these three variables and numbers then determines the stage of the cancer.

The grade of a cancer cell describes how similar or dissimilar the cell looks compared to a healthy cell observed under a microscope. Healthy tissue will have many different types of cells grouped together. If the tumor has many different types of cells and appears similar to healthy tissue, it is termed differentiated, or a low-grade tumor. Conversely, if the tumor appears very different from the healthy tissue, it is termed poorly differentiated, or a high-grade tumor. In general, the lower the grade of tumor, the better chance of treatment, survival, and prognosis.

As with most cancers, the prognosis of the disease depends on the type of cancer as well as the individual patients and the response to treatments. According to the University of California – Los Angeles, the 5-year survival rate for localized cancer is 62-97%, while those with metastatic disease have a 5-year survival rate of 8 – 41%.

Living With Kidney Cancer

People with cancer not only face physical challenges, but also mental and emotional challenges. It is important to understand your illness and treatment as it can make you feel more in control. Taking care of your emotional health is also vital. Family and friends can be an important source of support for you during this challenging time.

In addition, it is helpful to consider the following:

  • Explore all treatment options. Educate yourself on potential treatment methods and ask your doctor questions. Be sure to seek out reliable sources both online and in print. See the resources section for sources of information on brain cancer.
  • Weigh the benefits and risks of each treatment options. Ask yourself what the aim of your treatment should be, and what you wish to accomplish as you live with the disease.
  • Consider palliative care, a type of medical care specialized to help patients with terminal illnesses remain comfortable while living out their disease
  • Live out your dreams and goals to help you be as happy as possible. Don’t let prognosis or statistics discourage you from accomplishing want you want to accomplish



There are no official recommendations from the U.S. Preventive Services Task Force to suggest that it is beneficial to perform prophylactic kidney cancer screenings at the current time.


Unfortunately, there is no guaranteed preventative method to stop kidney cancer from developing.  However, cases of kidney cancer that are diagnosed early are less likely to progress and to carry worse a worse prognosis than cases that are diagnosed at later stages.

If you experience any of symptoms of kidney cancer, contact your physician immediately.

Medication And Treatment

RCC and Wilms tumor have five general treatment options:


  • Surgery to remove all or part of the kidney is often used for RCC treatment.
    • A partial nephrectomy is a surgery utilized to remove the cancer as well as some of the normal kidney tissue around it, while sparing the remaining healthy tissue.
    • A simple nephrectomy is a surgery to remove the entire kidney and cancer.
    • A radical nephrectomy involves removing the entire cancer, kidney, adrenal glands, nearby lymph nodes, and any other involved tissue. A person can live with a single kidney or even part of a single kidney. However, if this is not possible, he or she will be forced to undergo regular dialysis to remove toxins from the blood on a regular basis. A kidney transplant could then be performed to obviate the need to dialysis.
    • If surgical removal of the kidney proves difficult or impossible, a procedure known as an embolization can be performed. During this treatment, the artery, which supplies blood to the tumor, is scarred or surgically blocked to limit growth of the tumor.
  • Radiation. This treatment involves high energy x-rays focused on a specific site to kill cancer cells. The efficacy of radiation is cumulative, so multiple sessions of radiation are necessary for optimal treatment. Side effects of radiation include fatigue, skin damage, and necrosis of nearby structures to the cancer.
  • Chemotherapy uses medication via oral or intravenous routes to kill rapidly diving cells (which is characteristic of cancer cells, but other cells in the body divide quickly as well and may be killed by the chemotherapy, such as hair cells leading to baldness during chemotherapy). High-grade tumors may respond well to chemotherapy and shrink the tumor prior to a possible surgery, which makes resection easier for the surgeon. Besides the aforementioned baldness, chemotherapy may also cause loss of appetite, nausea, vomiting, weight loss, lethargy, and an increased risk of infection.
  • Targeted therapy utilizes drugs to identify and attack only the cancer cells, while avoiding normal healthy cells. Targeted therapy with antiangiogenic agents are used in renal cancers to prevent the formation of blood vessels that are supplying nutrients and oxygen to growing cancers. Monoclonal antibodies and kinases inhibitors are two examples of this type of treatment.
  • Biologic therapy uses specific compounds to amplify the body’s innate immune system to fight the cancer. This is also called biotherapy or immunotherapy.

Specific treatments for transitional cell cancer include:

  • Surgery. Specifically nephroureterectomy or segmental resection of the ureter
  • Laser surgery
  • Regional chemotherapy
  • Regional biologic therapy

Complementary and Alternative Treatment

As the definitive treatment for kidney cancer remains chemotherapy, radiation, and surgery, alternative treatments for this condition should only be considered after traditional interventions have been initiated or completed.

Complementary medicine, which refers to interventions performed in addition to traditional or standard treatment, are numerous and may provide additional symptom relief and improved quality of life for many patients. According to the National Center for Complementary and Integrative Health, these include:

Acupuncture – is particularly effective in alleviating treatment-related nausea and vomiting in cancer patients. It may even help control cancer pain. Although complications from acupuncture are rare, it is important to ensure that the needles are properly sterilized. Many cancer patients have weakened immune systems and more prone to infections.

Ginger – may help to control nausea secondary to cancer chemotherapy, especially when used along with standard anti-nausea medications.

Massage therapy – may help to alleviate symptoms experienced by many cancer patients, such as pain, nausea, anxiety, and depression. However, the massage therapist should be careful to avoid deep or too rigorous massage prior to physician approval, especially directly over a tumor or around sensitive skin, which is common following radiation treatments.

Mindfulness-based Stress Reduction – as a type of meditation, mindfulness-based stress reduction can help cancer patients by relieving anxiety, stress, fatigue, and general mood and sleep disturbances. As a result, this can lead to an overall improvement in quality of life.

Yoga – preliminary studies suggest that yoga may improve anxiety, depression, and stress in patients with cancer. It may also alleviate fatigue in breast cancer patients. However, additional studies need to be completed for better evidence and conclusions.

Hypnosis, relaxation therapies, and biofeedback – various studies are currently assessing the benefits of these activities in cancer patients.

Herbal supplements – a 2008 review of research regarding herbal supplements and cancer concluded that the scientific evidence is limited and many clinical trials were not well designed. Furthermore, there are specific concerns regarding some herbal supplements in terms of medication interactions. Thus, any use of herbal medications should be discussed thoroughly with your physician.

When To Contact A Doctor

If you are experiencing any of the signs or symptoms of kidney cancer (see above), you should seek medical attention as soon as possible. The earlier a diagnosis can be made, the earlier treatment can begin, which generally leads to improved outcomes and better prognosis.

Unless the symptoms are life threatening, you can make an appointment within a reasonable time period and do not need to visit the emergency department.


Questions For Your Doctor

Your medical team may consist of several healthcare professionals, including your primary care physician, a nephrologist , oncologist, and an oncologic surgeon. The National Cancer Institute can help you find a cancer center near you.

Questions For A Doctor

When you go to see your doctor, it’s good to have a list of the questions you’d like to have answered. Take a moment to write down some of the things you want to know. Your questions for your doctor might include some of these:

  • How far advanced is my cancer?
  • What are my options for treatment?
  • What is my prognosis?
  • What treatment would you recommend, and why?
  • What are the possible side effects?
  • Does my insurance cover these treatments?
  • What changes will I need to make in my day-to-day life?
  • Is there anything else I should know about my cancer?



Other useful resources to help you learn about kidney cancer can be found at:

The National Cancer Institute

Kidney Cancer Association

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