Kidney (renal) cancer develops when abnormal kidney cells begin growing out of control, forming a mass of malignant tissue that becomes a tumor. Nearly all forms of kidney cancers initially start in the lining of tubules (tiny tubes) within the kidney.
According to the American Cancer Society, nearly 64,000 new cases of kidney cancer will be diagnosed in the United States in 2017. The horrible affliction affects approximately one out of 63 individuals over the course of their lifetime and remains ranked in the top 10 of common cancers affecting Americans.
- Causes of Kidney Cancer
- Types of Kidney Cancer
- Kidney Cancer Symptoms
- Diagnosing Kidney Cancer
- Treating the Cancer
Types of Kidney Cancer
Most patients suffering from kidney cancer have developed renal cell carcinoma (renal cell adenocarcinoma/renal cell cancer) that represents nearly 90 percent of all kidney cancer cases. This form of the disease initially starts as a single tumor. However, some patients are diagnosed with two or more tumors in one or both kidneys simultaneously.
- Renal pelvis-associated urothelial cell carcinoma
- Mesoblastic nephroma
- Reninoma (juxtaglomerular cell tumor)
- Squamous cell carcinoma
- Mixed epithelial stromal tumor
- Renal oncocytoma
- Bellini duct carcinoma
- Wilm's Tumor
Though rare, cancerous tumors associated with those starting in the kidneys can originate in other areas of the body. This includes transitional cell carcinoma, adenocarcinoma, carcinosarcoma, teratoma, renal lymphoma, inverted papilloma, and renal pelvis associated carcinoid tumors.
Causes of Kidney Cancer
All cancers, including cancer of the kidney, begin with an abnormality in the DNA structure inside cells. The abnormality mutates the gene and causes the cell to grow uncontrollably during its maturation, reproduction, and death phases. Because the cell does not die, it continually reproduces, eventually forming a tumor cell. If the cancer is left untreated, it can easily metastasize (spread) beginning in the lymphatic system and out to distant body sites.
The most popular form of kidney cancer (renal cell carcinoma) usually begins in the tiny tubules in the nephron. Within time, the built-up tissue will develop a tumor that can grow in one kidney or simultaneously in both kidneys. Transitional cell carcinoma usually starts in the tubes connecting the bladder to the kidney or in that ureters or the bladder alone. While no direct cause has been found by scientists, doctors, and researchers, there are specific risk factors for most kidney cancers that include:
- Growing Older – The risk of developing kidney cancer increases significantly once the individual has reached 60 years of age.
- Gender – Without a known explanation, men have a 50 percent greater chance of developing kidney cancer compared to women.
- Obesity – Being extremely overweight can significantly increase the potential of developing the disease.
- Smoking Tobacco Products – Smokers are at a much greater risk of developing the disease. However, that risk and drop significantly once the individual quit smoking.
- High Blood Pressure (Hypertension) – Doctors have yet to determine if it is high blood pressure or the medication used to treat hypertension is the root cause of developing kidney cancer.
- Environmental Exposure – Individuals exposed to chemicals including cadmium, trichloroethylene, and asbestos have a high potential risk of developing renal cell carcinoma.
- Existing Kidney Condition – Individuals suffering from chronic kidney failure or are taking immunosuppressive medications after receiving a kidney transplant are more likely to develop renal cell carcinoma than those without an existing kidney condition.
- Genetic Predisposition – Individuals whose family have a history of kidney cancer has a five percent chance of inheriting the disease. However, only a few known genes have been correlated to the development of kidney cancer and many of those have been linked to certain genetic syndromes.
Kidney Cancer Symptoms
Many of the first signs of kidney cancer are not obvious. However, over time, individuals can develop certain signs, and symptoms associated with the disease including:
- Hematuria (blood found in urine)
- High blood pressure (hypertension)
- A lump or mass on the back or side
- Swollen legs or ankles
- Pressure or pain on the back or side
- Unexpected weight loss
- Loss of appetite
- Ongoing fatigue
- Low red blood cell count (anemia)
- Recurring fever not associated with infections, flu or the cold
- Enlarged testicle varicocele veins in men that form in clusters
May the signs and symptoms of cancer of the kidney also occur in other diseases. Because of that, the doctor must perform numerous tests to rule out kidney stones, urinary tract infections, bladder infections and other conditions that mimic the early stages of kidney disease.
Diagnosing Kidney Cancer
While some cases a kidney cancer are diagnosed by the symptoms associated with the disease, often, the early stages a kidney cancer are detected in it laboratory test results or imaging (CT scan, MRI, PET scan, x-ray) or when the patient is receiving to diagnose another condition. If the diagnostician suspects that the individual has a kidney cancer, they need to confirm the diagnosis with other tools including:
- A Comprehensive Medical History – The doctor will confirm whether the patient has a personal, medical, or family history of kidney cancer.
- A Complete Physical Examination – Through a physical exam, the doctor can be informed of health problems including developing kidney cancer. Typically, the doctor will examine the abdomen to look for an abnormal mass before ordering imaging and laboratory tests.
- A Complex Laboratory Test Panel – This test panel will include a urinalysis, complete blood count, and comprehensive blood chemistry test.
- Imaging Tests – The patient can undergo imaging tests including x-rays, magnetic field resonance imaging, sound waves or the use of radioactive material to create a picture of the body's internal organs. These tests can determine what is happening in the affected area, if cancer is present and has spread, or the treatment used by the patient has been effective.
Treating Kidney Cancer
The most successful approach to treating kidney cancer will often be based on a variety of factors including the patient's overall health, the type, and severity of cancer, and if it has metastasized (spread) to other areas of the body. Usually, the doctor will recommend:
- Nephrectomy – The surgeon can perform a nephrectomy surgical procedure to remove the diseased kidney and adjacent lymph nodes and surrounding tissue. Sometimes, the doctor also removes the adrenal gland associated with the affected organ. These surgeries are done robotically, laparoscopically through a tiny incision or through a large open incision operation.
- Nephron Sparing Procedure – During this procedure, the doctor will remove only the tumor and a small portion of how the surrounding tissue instead of removing the entire affected kidney. This can be a better option than a radical nephrectomy that removes the entire organ, which can diminish the need for dialysis and reduce the potential for future complications.
- Cryoablation – In this procedure, the doctor freezes the cancerous cells using a special insert needle using x-ray guidance into the kidney tumor.
- Radiofrequency Ablation – During the surgical procedure, the doctor inserts a special needle through the skin into the kidney tumor and use heat to destroy the cancer cells.
- Radiation Therapy – Using high-powered energy beams generated by x-ray machines, the therapist can isolate and destroy cancer in the kidney or to other areas in the body.
The type of treatment the patient will receive is highly dependent on the severity and type of cancer that have and whether it has spread to other areas of the body.