Kidney cancer is a form of cancer that develops in the kidneys. Your kidneys are two bean-shaped organs, each roughly the size of your fists, and are located behind the abdominal organs, one on each side of the spine. Their main function is to remove waste products and excess fluids from the body through urine. Additionally, the kidneys are responsible for balancing the body’s fluids, releasing hormones that regulate blood pressure, producing an active form of vitamin D that promotes strong and healthy bones, and controlling the production of red blood cells. With that said, when cancer forms in the kidneys, more than just the kidneys are affected.
What is Kidney Cancer
In adults, renal cell carcinoma is the most common type of kidney cancer. This type of cancer makes up about 90 percent of cancerous tumors. Urothelial carcinoma is another form of cancer that may arise from the central urine collection area of the kidney. Lymphoma and sarcoma of the kidney may occur but are considered very rare. Wilms tumor is a type of kidney cancer that generally develops in young children.
In recent years, the incidence of kidney cancer seems to be growing. One reason could be attributed to the fact that imaging techniques like computerized tomography (CT) scans are being utilized more frequently. Tests such as these may lead to a discovery of kidney cancer by accident. More often than not, kidney cancer is found at an early stage, when the tumors are still small and confined to the kidney, making treatment much easier.
Causes of Kidney Cancer
The causes of renal cell carcinoma, the most common form of kidney cancer, are not clear, , although several risk factors may be implicated.
Doctors know that kidney cancer begins when some kidney cells acquire mutations in their DNA. These mutations tell the cells to grow and divide more rapidly than normal. The accumulating abnormal cells form a tumor that can extend beyond the kidney itself. Some of these cells may break off and spread, also referred to as metastasizing, to distant parts of the body.
The risk factors that can increase the chances of developing kidney cancer include:
- Older age – Your risk of kidney cancer increases as you age.
- Obesity – People who are obese have a higher risk of kidney cancer than people who are considered average weight.
- High blood pressure (hypertension) – High blood pressure can increase your risk of developing kidney cancer.
- Treatment for kidney failure – People who receive long-term dialysis to treat chronic kidney failure have a greater risk of developing kidney cancer.
- Inherited syndromes – People who are born with certain inherited syndromes may have an increased risk of kidney cancer, such as those who have Von Hippel-Lindau disease, Tuberous Sclerosis Complex, Birt-Hogg-Dube syndrome, Hereditary Papillary Renal Cell Carcinoma, or familial renal cancer.
- Family history of kidney cancer – Even without an inherited syndrome, people who have a strong family history of renal cell cancer have a greater risk of developing kidney cancer.
- Smoking – Smokers have a greater risk of kidney cancer than nonsmokers do. The risk greatly decreases after you quit.
- Exposure to certain substances in the workplace – This may include, but is not limited to, exposure to cadmium or specific herbicides.
Symptoms of Kidney Cancer & Diagnosing
There are no current routine tests used to screen for kidney cancer without symptoms. Kidney cancer does not often cause signs or symptoms in its early stages; however, in the later stages of kidney cancer, you may experience the following signs and symptoms:
- Blood in your urine, which could appear pink, red, or cola colored
- Unexplained weight loss
- Intermittent fever
- Loss of appetite
- Persistent pain in your back or sides
Unfortunately, there are no blood or urine tests that can directly detect kidney cancer. As mentioned above, most often a tumor is diagnosed incidentally during a workup of an unrelated issue.
To properly diagnose kidney cancer, your doctor may want to utilize various imaging tests. These tests allow the doctor to visualize a kidney tumor or abnormality. Imaging tests might include an ultrasound, a computerized tomography (CT) scan, or magnetic resonance imaging (MRI). Another option is to remove a sample of kidney tissue, also referred to as a biopsy. The sample will be tested in a lab to look for signs of cancer.
Again, blood and urine tests can be performed, but they do not provide a clear yes or no answer to whether cancer is present in the kidney. These tests may provide your doctor with clues about what is causing your signs and symptoms.
Treating Kidney Cancer
With the help of your doctor, a treatment plan will be developed to best serve your needs. The best approach may depend on several factors: your general health, the kind of kidney cancer you have, whether the cancer has begun to spread, and your preferences on treatment.
Surgery is the main treatment for most types of kidney cancers, with the goal being to remove the tumor and preserving normal kidney function. Radiation and chemotherapy are rarely used for kidney cancer due to their lack of effectiveness in curing this type of cancer when isolated to the kidney. However, chemotherapy or immunotherapy are often used in patients with advanced cancer or metastases.
Some of the surgical procedures used to treat kidney cancer may include removing the affected kidney (radical nephrectomy) or removing the tumor from the affected kidney (partial nephrectomy).The type of surgery your doctor recommends will be determined by your cancer and its stage, as well as your health prior to the surgery. Surgery can carry a risk of bleeding and infection, so general health is always considered before surgery.
Aside from surgery, ablation of the tumor is another viable option to kill the cancer cells. This includes either heating (RFA- Radiofrequency Ablation) or cooling (Cryotherapy) to kill the cancer cells using temperature probes placed into the tumor. These procedures have proven effective in killing the cancer cells and decreasing risk of recurrence of the cancer without having to undergo a potentially major operation. Size and location of the tumor are key in determining whether a tumor is suitable for ablation. Generally, masses less than 4cm located in the periphery of the kidney are preferred. Cryotherapy is usually the treatment of choice when it comes to ablation, as it has proven to be slightly better with regards to cure rates.
For more information regarding surgery (radical and partial nephrectomy) and cryotherapy, please access the links provided.