Kidney, or renal, cancer refers to any type of 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 eliminates waste and excess fluid and electrolytes from the blood. They also control the production of red blood cells and regulate blood pressure.
Kidney cancers mainly originate in two parts of the kidney, the renal tubule and the renal pelvis. A cancer that starts outside the kidney and metastasizes to the kidney is not normally called kidney cancer.
Around 63,990 new cases of kidney cancer are diagnosed in the United States each year, causing over 14,000 deaths annually. In 2017, 40,610 American men and 23,380 women were expected to receive a diagnosis of kidney cancer.
Kidney cancer is one of the 10 most common cancers, affecting about 1 in every 63 people over a lifetime. It occurs more frequently among adults aged between 50 and 80 years.
Worldwide, North America has the highest rate of kidney cancer, but in developing countries, the incidence has been steadily increasing over the last three decades. This increase may be linked to a parallel rise in obesity rates, or it could be due to improved detection and diagnosis.
Growing rates of kidney cancer may be linked to a rise in obesity.
Symptoms do not usually appear in the early stages of kidney cancer.
In the later stages, the person may experience:
blood in the urine
a lump or mass in the back, near the kidneys
Less often, there may be:
a continuous pain in the side, near the kidneys
a lump in the abdomen
constant fever and night sweats
tiredness or fatigue
weight loss and loss of appetite
Other conditions can lead to similar symptoms, so it is important to see a physician if any of these occur.
Treatment options depend on several factors, including the patient’s general health, the type and stage of kidney cancer, and the patient’s own preferences.
Most kidney cancers are treated first by surgery. A person can function with just one kidney, so removing a kidney is an option.
Nephrectomy involves removing the kidney, the nearby adrenal gland, a border of healthy tissue, and the adjacent lymph nodes. The surgery can be done laparoscopically, through small incisions.
If the tumor is less than 1.5 inches, or 4 centimeters across, the surgeon may remove only part of the kidney in a partial nephrectomy.
If the cancer has spread outside the kidney, surgery may not cure it, but it can ease pain and make other non-surgical treatments more effective.
In nephron-sparing surgery, the tumor, but not the kidney, is surgically removed. This may be an option during the early stage of kidney cancer, or if the patient has only one kidney.
A patient who is unwell or frail may not be able to undergo surgery. In this case, a number of nonsurgical treatment options are possible.
It is important to get as much information as possible and to talk to a doctor or counselor about what to expect.
Embolization aims to block the flow of blood to the tumor. The surgeon inserts a small tube known as a catheter into the groin. X-ray images guide the catheter into the blood supply for the kidney. A special material passes through the catheter into the blood vessel, blocking the blood supply to the kidney and starving the tumor of oxygen and nutrients. This causes the tumor to shrink.
Cryoablation involves inserting one or more special needles, known as cryoprobes, through small incisions into the tumor. An imaging scan guides the process. A gas in the needles freezes the cells around the tip of each needle. Another gas warms thaws the tissue, and then the cells are refrozen. This freeze-thaw cycle kills the cancer cells.
Some pain may occur after the procedure, and, rarely, some bleeding, infection, and damage to the tissue close to the tumor.
Advanced or recurrent kidney cancer treatment is for kidney cancer that comes back, or kidney cancer that has spread out of the kidney.
Surgery aims to remove as much of the tumor as possible.
In biological therapy, or immunotherapy, drugs use the body’s own immune system to fight cancer. Examples are interferon and interleukin-2. Both are synthetic versions of chemicals that our bodies make. Side effects include nausea, vomiting, chills, elevated body temperature, and loss of appetite.
In targeted therapy, medicines interrupt the functions that cancer needs to survive, such as the blood supply.
Targeted therapies include:
Sunitinib, or Sutent
Sorafenib, or Nexavar
Radiation therapy cannot usually cure kidney cancer, but it may help reduce the spread and the severity of symptoms. Patients typically undergo a few minutes of treatment daily for a number of days. Radiation therapy that is used to control rather than to cure a cancer tends to have less severe side effects.
Side effects can include fatigue, nausea, and vomiting.
Complementary treatments may include taking certain vitamins alongside regular treatment. This should first be discussed with a physician. Some people have found that alternative treatments can relieve symptoms, but these can be unhelpful or hazardous, and should first be discussed with the medical team.
One way of staging kidney cancer is a four-stage system:
Stage 1: The tumor is under 2.8 inches, or 7 centimeters in diameter and it is limited to the kidney.
Stage 2: The tumor is greater than 2.8 inches, or 7 centimeters, in diameter, and it is still limited to the kidney.
Stage 3: The cancer is any size but has spread beyond the kidney to at least one other location. It may have reached the adrenal gland, nearby blood vessels, a lymph node, or the fat that surrounds the kidney.
Stage 4: The cancer has spread beyond the fatty tissue around the kidney, it affects at least one lymph node, or it has spread to other organs.
Below is a 3-D model of renal cell carcinoma, which is fully interactive.