Renal Cancer
Renal cancer, also known as kidney cancer, is a disease where cells in the kidney grow abnormally and out of control, forming tumors. It is one of the ten most common cancers in adults, with the majority of cases being renal cell carcinoma. While early stages often have no symptoms, advances in imaging and treatment have made kidney cancer more treatable than ever before.
Table of contents
- What is renal cancer?
- Types of renal cancer
- Who is affected?
- Symptoms and signs
- Risk factors
- Diagnosis
- Treatment options
- Living with renal cancer
What is renal cancer?
Renal cancer is a disease in which cells in the kidney tissue grow abnormally and out of control. Over time, these cells form a mass called a tumor (an abnormal growth of tissue). The kidneys are two bean-shaped organs, each about the size of a fist, located on either side of the backbone above the waist. Their main job is to filter excess water, salt, and waste products from the blood, turning these substances into urine. The kidneys also help control blood pressure and stimulate the production of red blood cells[1][2].
A cancerous or malignant tumor (a tumor that can spread to other parts of the body) can spread to other tissues and vital organs. When this happens, it is called metastasis (the spread of cancer from where it started to other parts of the body)[2].
Kidney cancer develops when something triggers a change in the cells, causing them to divide out of control. Many risk factors can increase the chance of DNA damage in cells that may lead to renal cancer[9].
- Kidneys
- Renal tubules
- Renal pelvis
- Ureters
Types of renal cancer
There are different types of kidney cancer. The most common is renal cell carcinoma (cancer that begins in the cells lining the tiny tubes in the kidney), which accounts for about 85% to 90% of all kidney cancers in adults. About nine out of ten kidney cancers are renal cell carcinomas[1][2].
Renal cell carcinoma has several subtypes. Clear cell renal cell carcinoma is the most common, making up between 70% and 80% of renal cell cancers. Other main types include papillary renal cell carcinoma (between 5% and 10% of cases) and chromophobe renal cell carcinoma (between 3% and 5% of cases)[8].
Around 5% of renal cell cancers have sarcomatoid features, meaning that some cancer cells look different under a microscope. Sarcomatoid renal cell cancer tends to grow more quickly than other types and is more likely to be diagnosed at an advanced stage[8].
Transitional cell carcinoma (also called upper urinary tract urothelial cancer) accounts for about 6% to 7% of all kidney cancers. This cancer usually begins in the area where the ureter connects to the main part of the kidney, called the renal pelvis. Transitional cell carcinoma can also occur in the ureters or bladder[2][8].
Renal sarcoma is the least common form of kidney cancer, accounting for only about 1% of cases. It begins in the connective tissues of the kidneys and, if not treated, can spread to nearby organs and bones[2].
Wilms tumor is the most common type of kidney cancer in children, accounting for about 5% of kidney cancers overall. Between 500 and 600 children are diagnosed with a Wilms tumor every year in the United States[2].
kidney cancer, renal cell carcinoma, renal cell cancer, hypernephroma, Grawitz tumor
Who is affected?
Kidney cancer represents about 3.7% of all cancers in the United States. Each year, more than 62,000 Americans are diagnosed with kidney cancer[2]. Globally, there are an estimated 400,000 cases of kidney cancer diagnosed each year[16].
Kidney cancer is most common in people between the ages of 65 and 74. The average age of those diagnosed with kidney cancer is 64. Men are about twice as likely as women to develop the disease. It is also more common in Native American and Black populations[1][2].
The risk of kidney cancer increases with age. Most cases are diagnosed between 60 and 70 years of age[1][5].
Symptoms and signs
Kidney cancer may not produce any noticeable symptoms in its early stages. Unfortunately, kidney cancer is often hard to detect early because symptoms may not appear until the tumor has begun to grow or spread. As the tumor grows, symptoms may begin to appear[1][2].
Common symptoms of kidney cancer include:
- Blood in the urine (called hematuria, which means red blood cells are present in the urine)
- A lump or mass in the kidney area or abdomen
- Flank pain (pain in the side of the body between the upper abdomen and the back)
- Tiredness or fatigue
- A general sense of not feeling well
- Loss of appetite
- Weight loss for no clear reason
- Low-grade fever that keeps coming back
- Bone pain
- High blood pressure
- Anemia (low red blood cell count)
- High calcium levels in the blood
- Swelling of the ankles or legs
Many of these symptoms can be caused by other conditions. If you notice any of these symptoms, it is important to talk to your doctor[4].
Risk factors
The exact cause of kidney cancer is not known. However, certain things can increase your chances of developing the disease. A risk factor (something that increases the chance of getting a disease) does not mean you will definitely get kidney cancer. Many people with risk factors never develop renal cancer[9].
Risk factors for renal cancer include:
- Smoking: People who smoke are at greater risk for kidney cancer. Smoking is the strongest risk factor. The longer a person smokes, the higher the risk. Tobacco use is a leading cause of cancer and death from cancer[2][9].
- Obesity: Being overweight or having obesity increases the risk of kidney cancer. In general, the more overweight a person is, the higher the risk[2][9].
- High blood pressure: Also called hypertension (a condition where the force of blood against artery walls is too high), high blood pressure has been linked to an increased risk of kidney cancer. It is not known whether the increased risk is due to high blood pressure itself or the medicines used to treat it[2][4].
- Family history: People who have family members with kidney cancer may have an increased risk of developing cancer themselves[2][9].
- Certain genetic conditions: Having certain inherited conditions, such as von Hippel-Lindau disease or hereditary papillary renal cancer, increases the risk[2][9].
- Long-term use of certain pain medicines: Taking certain pain medicines, including over-the-counter pain medicines, for a long time increases the risk[4][9].
- Chronic kidney disease and dialysis: Long-term dialysis and chronic renal failure are risk factors[2][5].
- Occupational exposure to certain chemicals: Being exposed to a chemical called trichloroethylene (a substance used to remove grease from metal) can lead to the development of kidney cancer. Workers in jobs such as mechanics, dry cleaners, and metal manufacturers may be exposed to this chemical[4][5].
- Long-lasting infection with hepatitis C[4]
- Kidney stones[4]
- Sickle cell trait[4]
Learning about risk factors for renal cancer can help you make changes that might lower your risk of getting it[9].
Diagnosis
Tests that examine the abdomen and kidneys are used to diagnose renal cancer. After renal cell cancer has been diagnosed, tests are done to find out if cancer cells have spread within the kidney or to other parts of the body[9].
The first step in diagnosing any disease is to complete a medical history and physical examination. To diagnose kidney cancer, your doctor may order tests and procedures including:
- Blood and urine laboratory tests: These tests can show how well the kidneys are working and check for signs of disease[10].
- Imaging tests: These create pictures of the inside of the body. Computed tomography (CT) scans (a type of X-ray that creates detailed pictures) and magnetic resonance imaging (MRI) (a test that uses magnets and radio waves to create images) are advanced imaging technologies that can show the difference between diseased and healthy tissues. Contrast-enhanced, triple-phase CT is the best way to detect renal masses, either cystic or solid[10].
- Ultrasound: This test uses high-frequency sound waves to create images of the kidneys[10].
- Biopsy: In some cases, a small sample of kidney tissue may be removed and examined under a microscope to check for cancer cells[10].
Renal tumors are often detected incidentally during a CT scan of the abdomen or chest that was ordered for unrelated symptoms. Blood in the urine (hematuria) serves as a warning sign that requires further evaluation and imaging leading to a diagnosis and treatment plan[1][19].
Treatment options
Treatment for kidney cancer depends on individual factors, including the exact location of the tumor, stage of the tumor, and the person’s general health. Certain factors affect the chances of recovery and treatment options[9][10].
The main treatments for renal cancer include:
Surgery: Surgery may be the first step in treating kidney cancer. It may be the only treatment needed, or part of a larger treatment plan. There are two main types of kidney cancer surgery, called nephrectomy (surgical removal of all or part of a kidney):
- Partial nephrectomy removes just the part of the kidney that contains the tumor and some of the tissue around it. This is now the preferred treatment for patients with early-stage kidney cancer when possible[13][15].
- Radical nephrectomy removes the whole kidney and often the adrenal gland above the kidney, the tissue around it, and the lymph nodes next to the kidney[13].
Most people do fine living with one remaining kidney, but close monitoring may be needed. Surgery can be performed as open surgery (through one large cut) or laparoscopic surgery (through several small cuts using special instruments)[13].
Systemic treatments: These are medicines that travel through the bloodstream to treat cancer cells wherever they are in the body. They may be given as pills or as liquids through a vein. The two main types of systemic treatments for kidney cancer are:
- Targeted therapy: These medicines target specific molecules on or in cancer cells. Most targeted therapies for kidney cancer work by either blocking the process of how new blood vessels grow and feed the cancer or blocking certain proteins in cancer cells that help them grow[13].
- Immunotherapy: This type of therapy takes advantage of a person’s own immune system to help kill cancer cells. Several newer immunotherapies, particularly checkpoint inhibitors, have become an integral part of the management of advanced or metastatic kidney cancer[13][16].
Systemic treatments are used for kidney cancer that is stage 4, has recurred (come back after previous treatment), or may be given before or after surgery in certain cases[13].
Radiation therapy: This treatment uses high-energy rays to kill cancer cells. It may be used in certain situations[11][13].
Ablation therapy: This uses extreme heat or cold to destroy tumors[13].
Observation or active surveillance: For small kidney cancers or in people who cannot have surgery, careful monitoring without immediate treatment may be an option[13].
Kidney cancer tends to be resistant to traditional chemotherapy[16].
Living with renal cancer
Living with renal cancer can be tough both physically and emotionally. A kidney cancer diagnosis can bring many different feelings, including shock, fear, confusion, anger, sadness, and anxiety. All of these feelings are normal. It may help to know that other people have felt the same way[21][22].
Managing daily life: Eating a well-balanced diet with lots of fruits and vegetables can support your overall health, help preserve your strength, and reduce your risk of infection. Getting enough calories to stay at a good weight is especially important during treatment. Regular physical activity, such as walking or gentle exercise, can improve energy levels, mood, and overall well-being[22][24].
Living with one kidney: You can live a normal and healthy life with one working kidney or with only part of a kidney. Your remaining kidney tissue can still filter waste and extra water from the blood. It is important to take care of your remaining kidney by quitting smoking if you smoke, maintaining a healthy diet, limiting salt and protein intake if advised by your doctor, staying well-hydrated, limiting alcohol, and avoiding exposure to harmful chemicals[26].
Managing symptoms and side effects: Work with your healthcare team to manage treatment side effects. Always attend follow-up appointments to ensure that your doctor knows if you are having side effects or any new or worsening symptoms. Keep a journal to track symptoms. Managing pain through medication and other approaches such as massage, meditation, and relaxation techniques can help improve your quality of life[22][24].
Emotional support: Talking to your family and friends about your cancer can provide help and support. If you find it easier to talk to someone other than your friends and family, you may prefer to speak to a counselor. Support groups can connect you with others who are going through the same diagnosis. Let your care team know about your feelings and worries so they can refer you to counselors or support groups[21][22].
Self-care: Self-care is an essential part of managing the discomfort you may be experiencing. It is about prioritizing your needs, care, and comfort. This can include getting enough sleep, spending quality time with loved ones, setting aside time for activities you enjoy, meditation, gentle exercise, or taking quiet time for yourself[22][24].
Follow-up care: After treatment has ended, regular follow-up appointments are important. The end of cancer treatment may bring mixed emotions. Even though treatment has ended, there may be other issues to deal with, such as coping with long-term side effects[26].
