What Is Kidney Cancer?
The kidneys are 2 large, bean-shaped organs. One is just to the left and the other to the right of the backbone. The lower rib cage protects the kidneys. The kidneys filter the blood and help the body get rid of excess water, salt, and waste products in the form of urine. Urine travels through long tubes (ureters) to the bladder where it is stored until the person passes the urine, or urinates.
Although we have two kidneys, it is possible to survive with less than even 1 complete kidney. Some people live without any working kidneys at all. Their blood is filtered by a machine in a process called dialysis.
There are many types of kidney cancer. Renal cell cancer is the most common, accounting for more than 9 out of 10 cases of kidney cancer. The information that follows refers only to renal cell cancer.
Renal Cell Cancer
Like all cancers, kidney cancer begins small. It usually grows as a single mass within the kidney, but more than one tumor can be present. In some cases, tumors are found in both kidneys simultaneously. The cancer, which may not be detected until it has become quite large, is usually found before it has spread to other organs.
There are 5 main types of renal cell cancer:
clear cell
papillary
chromophobe
collecting duct
unclassified
Approximately 8 out of 10 cases of renal cancer are clear cell.
How common is kidney cancer?
The American Cancer Society estimates that there will be about 38,890 new cases of kidney cancer in 2006 in the United States and approximately 12,840 people will die from the disease. Although kidney cancer is not common among people under age 45, these numbers include both children and adults.
What Causes Kidney Cancer?
Although an exact cause is not known, there are certain risk factors are linked to the disease. A risk factor is anything that increases a person's chance of getting a disease such as cancer. Some risk factors, such as smoking, can be controlled. Others, like a person's age or family history, can't be changed. But having a risk factor, or even several, doesn’t mean that a person will get the disease.
Risk Factors That Can Be Controlled:
Smoking: Cigarette smoking increases the risk of kidney cancer by about 40%. and drops slightly if the smoker quits.
Weight: Obesity increases the risk of kidney cancer.
Exercise: Several studies have found that people who are not very active are more likely to get kidney cancer than people who exercise.
Job hazards: Many studies suggest that exposure to certain chemicals on the job increases the risk of kidney cancer.
Other Risk Factors :
Inherited risk factors: Some people inherit a tendency to get certain types of cancer.
Family history: People with family members who have kidney cancer (especially a brother or sister) have a much higher chance of getting the disease.
High blood pressure: This also increases the risk. People with high blood pressure are often treated with drugs, so it is hard to tell if the higher risk is caused by the drugs or the high blood pressure itself.
Medicines: A once popular pain-reliever (phenacetin) has been linked to kidney cancer. Because this medicine has not been used in the United States for over 20 years, it no longer appears to be a major risk factor. Some drugs used to treat high blood pressure and certain heart problems have also been linked to kidney cancer. It’s not clear whether the higher risk is caused by the drugs or the disease. But people who need these drugs should take them.
Kidney disease: People with advanced kidney disease who need to be on dialysis have a higher risk of kidney cancer. Dialysis is a treatment used to remove toxins from the body of people whose kidneys are not working.
Gender: Kidney cancer is found about twice as often among men as among women. This could be because men are more likely to be smokers and to be exposed to cancer-causing chemicals at work.
Can Kidney Cancer Be Prevented?
Many cases of kidney cancer could be prevented. Stopping smoking can lower your risk. Being overweight and having high blood pressure are also risk factors for kidney cancer. You may reduce your risk by getting treatment for high blood pressure if you need it, staying at a healthy weight, and eating plenty of fruits and vegetables.
Also, you should avoid exposure to harmful substances such as cadmium, asbestos, and organic solvents in the workplace.
How Is Kidney Cancer Found?
Kidney cancer is often found at a late stage because it can become quite large without causing any pain. Since the kidneys are deep inside the body, there is no way to see or feel small tumors during a physical exam. And there are no simple tests to find kidney cancer early.
Small amounts of blood in the urine could point to kidney cancer, but there are many other causes of blood in the urine, including infections and kidney stones. And some people with kidney cancer don’t have blood in their urine until the cancer is quite large.
While tests such as CT scans (computed tomography) and MRI (magnetic resonance imaging) can sometimes find small tumors, these tests are expensive and can’t always tell cancerous tumors from benign ones. They are recommended routinely only for a very few people with certain risk factors.
It is important to tell your doctor if members of your family have had kidney cancer or other problems linked to kidney disease.
Often kidney cancer is found "incidentally," meaning that the cancer is found during tests for some other illness such as gallbladder disease. The survival rate for kidney cancer found this way is very high because the cancer is usually found at a very early stage.
Signs and Symptoms of Kidney Cancer
Possible signs and symptoms of kidney cancer include:
blood in the urine
low back pain on one side (not from an injury)
a mass or lump in the belly
tiredness
weight loss, if you are not trying to lose weight
fever that doesn’t go away after a few weeks and that is not from a cold, the flu, or other infection
swelling of ankles and legs
Talk to your doctor if you notice any of these problems. They are often caused by less serious conditions, but only your doctor can tell for sure. If there is any reason to suspect kidney cancer, the doctor will take your medical history and do a
physical exam.
Imaging Tests
CT scan (computed tomography): several x-rays are taken from different angles and then combined by a computer to give a detailed picture of the inside of the body. A CT scan is one of the most useful tests for finding a mass inside your kidney.
MRI (magnetic resonance imaging): strong magnets and radio waves are used to produce a picture of the inside of the body. An MRI gives more detailed pictures than a CT scan. It can help doctors tell if the cancer has spread to the brain or spinal cord.
Ultrasound: sound waves are used to produce an image of internal organs. A wand (transducer) is rubbed over the skin. This test is painless and easy to take.
PET scan (positron emission tomography): PET scans involve injecting a slightly radioactive form of sugar into the bloodstream. The substance travels throughout the body. Cancer cells absorb large amounts of the sugar. A special camera is then used to find these deposits and turn them into pictures. This test is useful to see if the cancer has spread to lymph nodes. They can also be used when the doctor thinks the cancer has spread but doesnÂ’t know where.
Intravenous urography: a special dye is injected into the bloodstream. X-rays taken afterwards can help identify a cancer or show kidney damage caused by the tumor. This test is sometimes called an IVP (intravenous pyelogram).
Angiography: this test also uses x-rays and a contrast dye, but the dye is injected into an artery leading to the kidney. It can help outline the blood vessels feeding a kidney tumor and help doctors plan surgery to remove the tumor.
Chest x-ray : a chest x-ray can show if the cancer has spread to the lungs.
Bone scan: a slightly radioactive substance is injected into the bloodstream, which then travels to the bones, where it is detected by a special camera. A bone scan can to help find cancer and other diseases that affect the bones. By itself, a bone scan canÂ’t show the difference between cancer and other problems, so other tests may be needed.
Lab Tests
Urinalysis: this test looks for blood and other substances in a urine sample. Sometimes special microscopic tests will be done to look for cancer cells.
Blood tests : blood tests are done to look for problems that might occur along with kidney cancer such as too few or too many red blood cells.
FNA biopsy (fine needle aspiration): this test may be done if other tests have not shown for sure that there is a cancer. During FNA, a thin needle is placed through the skin to remove fluid or small pieces of tissue from the kidney or from another place where the cancer may have spread. The sample is looked at under a microscope.
Staging
Staging is the process of finding out how far the cancer has spread. This is very important because your treatment and the outlook for your recovery depend, to a large extent, on the stage of your cancer.
While there are 2 staging systems for renal cell cancer, each uses Roman numerals from I through IV (1-4) to describe the stages. In general, the lower the number, the less the cancer has spread. A higher number, such as stage IV, means a more serious cancer. Ask your doctor to explain the stage of your cancer in a way you can understand.
Your doctor will consider both the grade (discussed earlier) and stage of your cancer when recommending a treatment plan.
How Is Kidney Cancer Treated?
Surgery :Surgery is the main treatment for renal cell cancer. The chances of surviving kidney cancer without having surgery are poor. Depending on the type and stage, you might have one of the following types of surgery:
Radical nephrectomy: In this operation, the whole kidney, the adrenal gland (the gland that “sits” on top of the kidney), and some nearby fatty tissue are removed. Nearby lymph nodes are sometimes removed as well (regional lymphadenectomy).
Partial nephrectomy: The surgeon removes only the part of the kidney with the cancer. The rest of the organ is left in place. This might be a choice if your cancer is in both kidneys, if you have only one kidney, or if there is a very small cancer in only one kidney.
“Keyhole” surgery: In this method for removing kidney tumors, the operation is done through small incisions. The medical term for this approach is laparoscopic nephrectomy. Through these incisions, the surgeon can use instruments to do the surgery. The advantages include a shorter hospital stay, faster recovery, and less pain afterwards.
Removal of metastases: Sometimes surgery is done to remove cancer that has spread. This can help relieve pain or other symptoms even though it does not usually help patients live longer. It is most often done if there are only a few tumors that can be removed easily.
Arterial embolization: This is a technique that blocks the artery feeding the kidney with the cancer. This method, which is rarely done, is sometimes used before surgery to kill some of the cancer cells and to reduce bleeding during the operation.
Some people can’t have surgery because of poor health (heart or lung problems, for example). In those cases, radiation therapy or arterial embolization may be the best choices for treatment.
Radiation Therapy
Radiation therapy is treatment with high-energy rays (such as x-rays) to kill or shrink cancer cells. External radiation aims radiation from outside the body on the cancer.
This type of treatment is sometimes used as the main treatment for kidney cancer for patients who cannot have surgery. It can also be used to ease symptoms such as pain, bleeding, or problems caused by the cancer spreading. But kidney cancer does not respond well to radiation. It is not often used routinely after surgery because studies have shown that is doesn’t help people live longer.
Side effects of radiation can include:
mild skin changes that look like sunburn
nausea
diarrhea
tiredness
Often these go away after a short while. Radiation can also make the side effects of chemotherapy worse. Radiation to the chest area can cause lung damage and lead to trouble breathing and shortness of breath. Side effects of radiation to the brain usually become most serious 1 or 2 years after treatment and can include headaches and trouble thinking.
Chemotherapy
Chemotherapy is the use of anticancer drugs injected into a vein or given as a pill. These drugs enter the bloodstream and reach throughout the body, making the treatment useful for cancers that have spread to distant organs.
Unfortunately, kidney cancer does not usually respond well to chemotherapy.
Chemotherapy can have some side effects. These side effects depend on the type of drug, and the frequency and duration.
Most side effects go away when treatment is over. Anyone who has problems with side effects should talk with their doctor or nurse.
Biologic Therapy (Immunotherapy)
Because chemotherapy for kidney cancer does not work very well, doctors are looking at a newer approach called biologic therapy. This is treatment that boosts the body’s own defense system to help fight off or destroy cancer cells.
There are several different kinds of biologic therapy used to treat renal cell cancer.
Drugs called cytokines have become one of the standard treatments for kidney cancer that has spread. For a small number of patients, cytokines can shrink the cancer to less than half its original size.
The side effects of immunotherapy can be severe and, rarely, fatal. For this reason, only doctors experienced in the use of cytokines should give this treatment to people with kidney cancer.
Hormone Therapy
Some doctors treat patients who have widespread kidney cancer with a drug called Provera that acts like the female hormone progesterone. A very few patients will show improvement with this treatment. It has few side effects except for some fluid retention and weight gain.
Pain Control
Pain is a major concern for some people with advanced kidney cancer. Be sure to tell your doctor or nurse about any pain you are having. Unless they know about your pain, they can’t help. It is important for you to use treatments that can help relieve pain.
For most people, treatment with morphine or other opioids (medicines related to opium) will reduce the pain quite a lot. For the treatment to work best, the pain medicines must be taken on a regular schedule, not just when the pain becomes severe. Some forms of morphine and other drugs have been developed that need to be given only once or twice a day.
