Kidney, or renal, cancer refers to any cancer that involves the kidney. Older age, obesity, smoking, and high blood pressure increase the risk of developing kidney cancer.
The kidneys are part of the urinary system, which removes waste and excess fluid and electrolytes from the blood. These organs also produce hormones that aid the production of red blood cells and help regulate blood pressure.
Kidney cancers are those that start in the kidney. Cancer that develops elsewhere in the body and then spreads to the kidney is not kidney cancer. If it starts in the bladder, for example, it will be bladder cancer.
In 2019, the American Cancer Society (ACS) expect doctors to diagnose about 73,820 new cases of kidney cancer. They also predict that close to 14,770 people will die of kidney cancer.
The ACS add that kidney cancer is one of the 10 most common cancers. It affects about 1 in every 48 men and 1 in every 83 women over a lifetime. The average age at diagnosis is 64 years, and the disease is rare before the age of 45 years.
Symptoms do not usually appear in the early stages of kidney cancer, but some people may experience them, particularly when cancer is more widespread.
Some possible symptoms include:
- blood in the urine
- pain in the side
- a lump or mass in the side or lower back
- a fever and night sweats
- fatiguehigh blood pressure
- weight loss and loss of appetite
- vision changes
- changes in liver function
- an enlarged testicle or varicose veins in the testes
Anyone who experiences these symptoms should see a doctor.
Treatment options depend on several factors, including:
- overall health
- the type and stage of kidney cancer
- personal preferences
- previous treatments for cancer
In most cases, surgery is the first option. The surgeon may remove part or all of a kidney, as well as tissue from around the tumor. If necessary, they may need to remove lymph nodes and other tissues.
A person can function with just one kidney, so removing a whole kidney is an option.
Laparoscopic surgery, which requires only small incisions, is often possible.
A person who is unwell or frail may not be able to undergo surgery. In this case, some nonsurgical options are possible.
Embolization: The surgeon inserts a catheter and passes a synthetic material through it into the blood vessel. This material blocks the blood supply to the kidney, which starves the tumor of oxygen and nutrients and causes it to shrink.
Cryoablation: A doctor will insert one or more special needles called cryoprobes through small incisions into the tumor. Gases in the needles freeze the cells, then warm them, then freeze them again. This freeze-thaw cycle kills cancer cells. The procedure can be painful, and it may cause some bleeding, infection, and damage to the tissue close to the tumor.
Chemotherapy is the use of powerful drugs to attack and kill cancer cells, stopping or delaying the progress of cancer. These drugs often affect the whole body, and they can have widespread adverse effects. However, the effects often subside after treatment finishes.
Immunotherapy boosts the ability of the body’s immune system to fight cancer. Common side effects include nausea, vomiting, chills, elevated body temperature, and loss of appetite.
In targeted therapy, drugs target specific functions or genes that play a role in the development of cancer. They interrupt the functions that are necessary for cancer to survive and grow.
Alongside conventional treatments, some people say that taking certain vitamins may help. However, the individual should discuss this first with their doctor, as some supplements can worsen symptoms or result in new health problems.
Cancer develops over time. In the earliest stages, cells change to become precancerous. Sometimes, these cells can develop into cancer.
Localized: Cancer is only in the kidneys and has not spread.
Regional: Cancer has spread to nearby tissues.
Distant: Cancer has spread throughout the body and is affecting other organs, such as the liver.
Treatment is more likely to be effective if a person receives a diagnosis in the early stages. The further that cancer has spread, the more challenging it is to treat.
Doctors do not know exactly what causes kidney cancer, but genetic and environmental factors may play a role.
Cancer starts when there is a change in the structure of DNA in cells, which causes them to grow uncontrollably. Eventually, a tumor will form.
Without treatment, cancer grows and spreads. It usually spreads through the lymphatic system, which is a series of nodes or glands that exist throughout the body.
There are several different types of kidney cancer. They include the following:
Renal cell carcinoma (RCC) typically starts in the cells that line the tiny tubes of the nephron. Tumors usually grow as a single mass. Sometimes, however, more than one tumor can grow in one kidney or even in both kidneys. About 85% of kidney cancers in adults are this type.
Transitional cell carcinoma, or urothelial carcinoma, develops in the tissue that forms the tubes connecting the kidneys to the bladder. This type can begin in the ureters and also in the bladder. Approximately 10–15% of adult kidney cancers are of this type.
Wilms’ tumor is a childhood kidney cancer that results from the loss or inactivation of a tumor suppressor gene. Tumor suppressor genes usually inhibit tumor growth and control cell growth.
Risk factors for RCC, the most common type of kidney cancer, include:
Age: Kidney cancer is rare before the age of 45 years.
Gender: RCC affects about twice as many men as women.
Obesity: People with obesity have a higher risk, possibly due to hormonal factors.
Smoking: Regular tobacco smokers have a higher risk, but the risk starts to drop after the person quits.
High blood pressure: Doctors are unsure whether it is hypertension itself or the medication that people use for it that leads to an increased risk of RCC.
Toxic chemicals: People who work with certain chemicals, such as cadmium, some herbicides, and organic solvents, may have a higher risk.
Medications: The use of diuretics and some older pain relief medications may put a person at higher risk.
Dialysis: People with advanced kidney disease who receive dialysis may have a higher risk. It is not clear whether this is due to the disease or the treatment.
Genetic and hereditary factors: People with certain conditions may be more likely to develop RCC. Examples include von Hippel-Lindau disease, hereditary papillary renal cell carcinoma, and Cowden syndrome.
Being aware of these risk factors and following a healthful lifestyle — including not smoking — can help reduce the risk of kidney disease for many people.
If a person has symptoms of kidney cancer, a doctor will:
- ask about their symptoms
- ask about their personal and family medical history
- carry out a physical examination
- order some tests
If a doctor suspects that a person might have kidney cancer, they may order one or more of the following tests.
Blood and urine tests: These tests can rule out other possible causes of symptoms, such as kidney stones or an infection.
Imaging scans: An ultrasound, MRI, or CT scan can help the doctor identify changes in the shape of the kidney that could be due to cancer. The person may need to drink a dye first to improve the clarity of the images.
Biopsy: The doctor will use imaging technology to guide this procedure. They will insert a needle to remove a small sample of kidney tissue for examination under a microscope. Only a biopsy can confirm the presence of cancer.
The doctor may also recommend other tests to check for transitional cell cancer.
Getting an early diagnosis generally improves a person’s outlook. Medical experts use past statistics to calculate how likely people with cancer are to live at least 5 years after diagnosis compared with those in the overall population.
For kidney cancer, the percentages are:
- 93% for cancer that has not spread beyond the kidneys at diagnosis
- 69% for cancer that has affected nearby tissues
- 12% for cancer that has reached other parts of the body
Many different factors affect these estimates, including the type of kidney cancer and the age and overall health of the individual.
To learn more about the outlook for kidney cancer and to get some tips on living with this disease, click here.
Kidney cancer is treatable in many cases. It is important to seek help if symptoms appear, as treatment is more likely to be effective in the early stages.
After treatment, kidney cancer can sometimes go into remission, which means that a person no longer has cancer. However, some people can experience long term health problems as a result of cancer treatment.
Following a healthful lifestyle and attending regular health checkups can help an individual feel more in control of their health.
Anyone who has concerns about symptoms or kidney cancer should speak to their doctor.