The kidneys are fist-sized, bean-shaped organs that are attached to the upper back wall of the abdomen and act as the body’s filter for the blood. They filter out things like excess salt, waste products and water, which are then made into urine. Kidney cancer is a type of cancer that forms in the kidneys. Cancer can begin in any part of the body and once the cancerous cells spread, can settle in any area causing a tumor or overgrowth of cells.
The kidneys also have adrenal glands, which rest above each kidney on the right and left side of the body. The kidneys and adrenal glands are then wrapped in a thin, fibrous layer known as Gerota’s fascia and a layer of fat. After urine is made during the filtering process, it leaves the kidneys through long slender tubes called ureters, which connect each kidney at the area known as the renal pelvis. Urine then flows into the bladder where it is stored until urination happens.
The kidneys are also responsible for helping to control blood pressure by making the hormone called renin. They also help to ensure the body has enough red blood cells by making another hormone called erythropoietin. This hormone is connected to the bone marrow and instructs it to make more red blood cells.
While the kidneys are detrimental to our existence and survival, humans can live with only one kidney. In some cases, people are living with no kidneys due to illness, accident, or other medical reasons. These folks must have a procedure called dialysis done to have their blood filtered to do the job that the kidneys would if present.
What are the main types of kidney cancer?
Renal cell carcinoma, renal cell adenocarcinoma, is the most common type of kidney cancer diagnosed in the United States. Nearly nine out of ten cases of kidney cancer are renal cell carcinoma. While this cancer usually grows as a single tumor inside of the kidney, there can be two or more tumors in one kidney, or both kidneys.
There are numerous subtypes of renal cell carcinoma, and the exact type of cancer will be determined after a biopsy is taken and the cells are examined under a microscope. This will be a factor in your treatment plan and help your doctor identify any inherited genetic syndromes. Some of those subtypes are:
–Clear cell renal cell carcinoma is the most common form of renal cell carcinoma. About seven out of ten people with renal cell carcinoma have this kind of cancer. When seen under a microscope, the cells that make up clear cell renal cell carcinoma look very pale or clear.
–Papillary renal cell carcinoma is the second most common subtype – about one in ten renal cell carcinomas are of this type. These cancers form little finger-like projections, also called papillae, in some, if not most, tumors. Some doctors call these cancers chromophilic because the cells take in certain dyes and look pink under the microscope.
–Chromophobe renal cell carcinoma this subtype accounts for about five percent (roughly five cases in one hundred) of renal cell carcinomas. The cells of these cancers are also pale, like the clear cells, but are much larger and have certain other features that can be recognized when looked at with a microscope.
–Rare types of renal cell carcinoma have subtypes that are very rare, each making up less than one percent of renal cell carcinomas:
- Collecting duct renal cell carcinoma
- Multilocular cystic renal cell carcinoma
- Medullary carcinoma
- Mucinous tubular and spindle cell carcinoma
- Neuroblastoma-associated renal cell carcinoma
–Unclassified renal cell carcinoma occur rarely, as renal cell cancers are labeled as unclassifiedbecause the way they look does not fit into any of the other categories or because there is more than one type of cell present.
There are also other types of kidney cancer that include transitional cell carcinomas, Wilms tumors and renal sarcomas.
–Transitional cell carcinoma occurs more frequently. Of every one-hundred cancer in the kidney, about five to ten are transitional cell carcinomas, also known as urothelial carcinomas. These do not always originate in the kidney, but often in the lining of the renal pelvis. Cancers that develop from these cells often end up being bladder cancer.
–Wilms tumor or nephroblastoma almost always occur in children. This is a rare cancer to occur in adults.
–Renal sarcoma is a type of rare kidney cancer that begins in the blood vessels or connective tissues of the kidney. These make up less than one percent of diagnosed kidney cancers.
Are there other types of tumors that affect the kidneys?
Yes, some kidney tumors called benign kidney tumors, can be removed by destroying them, removing them, or using techniques like radiofrequency ablation. The treatment for these tumors depends on the size, problems cause, location, number of tumors, and the patient’s general health.
–Renal adenoma is the most common benign kidney tumors. They are small, slow-growing tumors that are often found on imaging tests when the doctor is looking for something else. Seen with a microscope, they look a lot like low-grade renal cell carcinomas.
In rare cases, tumors first thought to be renal adenomas turn out to be small renal cell carcinomas. Because they are hard to tell apart, suspected adenomas are often treated like renal cell cancers.
–Oncocytoma are benign kidney tumors that can sometimes grow quite large. As with renal adenomas, it can sometimes be hard to tell them apart from kidney cancers. Oncocytomas do not normally spread to other organs, so surgery often cures them.
–Angiomyolipoma are rare. They often develop in people with tuberous sclerosis, a genetic condition that also affects the heart, eyes, brain, lungs, and skin. These tumors are made up of different types of connective tissues. If they are not causing any symptoms, they can often just be watched closely. If they start causing problems like pain or bleeding, they may need to be treated.
What are the risk factors for kidney cancer? Can I do anything to prevent this cancer from developing?
Risk factors are anything that can raise your chances of developing a cancer or illness. There are many risk factors that do increase your risk for developing kidney cancer. They are:
- Smoking.
- Obesity.
- Workplace exposures.
- Family History of Kidney cancer.
- High blood pressure.
- Medications.
- Gender.
- Race.
- Hereditary factors.
Preventing kidney cancer is not precisely possible, as the body tends to grow cancerous cells whenever it deems fit. In most kidney cancer cases, doctors are unable to find the cause for the abnormal cell growth and eventual cancer cells. Reducing your risk factors can help you to avoid cancer but comes with no guarantee. If you use tobacco products, stop immediately. If you are obese or overweight, find a way to balance your life and come to a manageable, steady weight. By doing these things, you will also help to control your blood pressure and blood sugar, which can also play a role in body homeostasis and help to prevent cancer.
What are the signs and symptoms of kidney cancer?
Early kidney cancers do not have many visible symptoms. Larger sized or more advanced kidney cancer may show these signs:
- Blood in the urine or hematuria
- Low back pain on one side that is not caused by injury
- A mass or lump on the side or lower back
- Fatigue or extreme tiredness
- Loss of appetite
- Weight loss not caused by dieting
- Fever that is not caused by an infection and that does not go away
- Anemia or low red blood cell counts
While these symptoms can mimic many other illnesses and types of cancer, if you are experiencing any of these, see your doctor so that the root cause for your struggle can be found.
What is the treatment plan for kidney cancer?
The treatment plan for your case of kidney cancer may be different from another who is also working through life with this cancer. Your biopsy results and exact genotyping of your cancer will give your doctor the results and answers as to which treatment is best for you. Here are descriptions of some of the treatment plans that are given to kidney cancer patients.
There are many doctors and specialists who can treat your kidney cancer. You may see one or more of these kinds of doctors on your journey. A urologist is a doctor who specializes in treating diseases of the urinary system and male reproductive system. A radiation oncologist administers that radiation therapy you may be prescribed. A medical oncologist is a doctor who treats cancer with medications like chemotherapy and other medications like it.
- Local treatments are also called local therapies and are done directly to the tumor without affecting the rest of the body in its entirety. These are most often used for early-stage cancers. These may include surgery, active surveillance, ablation, or radiation therapy.
- Systemic treatments can be used to help treat this cancer. These are given by mouth or vein, pushing the medication directly in to the blood stream. This treatment can reach cancer anywhere in the body. Therapies used for this systemic method are targeted therapy, immunotherapies, or chemotherapy.
- Palliative treatment is done when other options have been exhausted. This treatment focuses on comfort and care, ensuring that symptoms are controlled.
It is important to discuss all treatment plans and options available to you at the time of diagnosis. Early detection is key. If you suspect you may be dealing with kidney cancer, do not hesitate to make an appointment with your medical care team to begin proper testing for diagnosis and treatment.
Citations:
American Cancer Society
National Kidney Foundation
PKD Foundation