What is Kidney Cancer?

A kidney tumor is an abnormal growth in the kidney. The terms “mass,” “lesion” and “tumor” are often used interchangeably. Tumors may be benign (non-cancerous) or malignant (cancerous). The most common kidney mass is a fluid-filled area called a cyst. Simple cysts are benign, do not turn into cancer and usually do not require follow-up care. Solid kidney tumors can be benign, but are cancerous more than 90 percent of the time. It is possible that kidney cancer can grow into the renal vein and vena cava. The renal vein is the kidney’s primary draining vein and the vena cava is the vein that takes blood to the heart. The portion of the cancer that extends into these veins is called “tumor thrombus.” Imaging studies, such as an MRI, can help to find out if tumor thrombus is present. For a tumor to grow and spread, it must stimulate new blood vessels to provide the tumor with nutrients and oxygen. This process, known as angiogenesis. Kidney cancers are considered very angiogenic and are very efficient at travelling through the blood vessels in the body. They do this by secreting a protein called vascular endothelial growth factor (VEGF). VEGF acts on nearby blood vessels and stimulates them to sprout new vessels to supply the tumor. Kidney cancer can form in the small tubes inside the kidney. Those tubes are located in the center of the kidney where urine collects and used to filter blood. The most common kidney cancer is called renal cell carcinoma.

SIGNS AND SYMPTOMS OF KIDNEY CANCER

Unfortunately, kidney cancer does not have early symptoms but you should see your doctor if you notice the following:

• Blood in your urine
• Lump in your abdomen
• Unexplained weight loss
• Pain in your side
• Loss of appetite

If cancer spreads (metastasizes) beyond the kidney, symptoms depend on the organ involved. Shortness of breath or coughing up blood may occur when cancer is in the lung. Bone pain or fractures may occur when cancer is in the bone. When cancer is in the brain, you may have neurologic symptoms. In some cases, kidney cancer causes related conditions called paraneoplastic syndromes. These syndromes occur in about 20 percent of kidney cancer patients and can occur in any stage, including cancers confined to the kidney. Symptoms from paraneoplastic syndromes include weight loss, loss of appetite, fever, sweats and high blood pressure. In many cases, the paraneoplastic syndrome improves or disappears after the cancer is removed.

CAUSES & RISK FACTORS

Researchers have found several risk factors that make you more likely to develop kidney cancer. The following may increase your risk of developing kidney cancer:

• Smoking
• Hypertension
• Obesity
• Family history of kidney cancer
• Chronic kidney failure and/or dialysis
• Diet with high caloric intake or fried/sautéed meat
• Von Hippel Lindau disease (rare genetic disorder that causes tumor growths)
• Tuberous sclerosis (common genetic condition that produces growths in the body from birth throughout adulthood)

SCREENING AND TESTING FOR KIDNEY CANCER

Unfortunately, there are no blood or urine tests that detect kidney cancer. When kidney cancer is suspected, your doctor will order a kidney imaging study. The initial imaging study is usually an ultrasound or CT scan. In some cases, a combination of imaging studies may be needed to completely evaluate the tumor. If cancer is suspected, you should be evaluated to see if it has spread beyond the kidney (metastasized). An evaluation consists of imaging studies such as an ultrasound or CT scan. These tests may be followed by an MRI, X-rays and blood tests. You may also need a bone scan if you have had bone pain, recent fractures, or abnormal blood tests. Additional tests may be ordered if your doctor feels they are needed to completely evaluate the tumor.

KIDNEY CANCER TREATMENT OPTIONS

The primary treatment option for kidney cancer is surgery to remove all or part of the kidney and the tumor; kidney cancer does not respond well to radiation and chemotherapy treatments.

Radical Nephrectomy versus Partial Nephrectomy (Kidney-sparing)

The removal of the entire kidney is called a radical nephrectomy. Depending on your disease state and tumor location, you may not have to lose your entire kidney to surgery. An emerging surgical technique, called partial nephrectomy, aims to remove only the diseased part of your kidney and spare the healthy, functioning kidney tissue. Sparing kidney tissue is important because studies show that patients who have their entire kidney removed are more likely to suffer from chronic kidney disease (CKD) after surgery compared to patients who receive a kidney sparing partial nephrectomy. In fact, the American Urological Association states that partial nephrectomy is the gold standard treatment option for small to medium-sized kidney tumors or masses.

Surgical Treatment Options

Thermal Ablation – An alternative therapy for kidney cancer is to treat the cancerous tissue using extreme temperatures. Cryotherapy freezes the tissue to kill cancer cells where radiofrequency uses heat to destroy cancer cells. Both methods use several tiny probes that are inserted into the kidney tumor either through an open or laparoscopic surgical technique. Thermal ablation therapy does not take the cancerous tissue out of the body, but rather uses probes to deliver extreme temperatures to tumors in the hopes that all cancerous tissue is destroyed. An important note, studies show that patients treated with ablation (cryoablation or radiofrequency) had a significantly higher rate of recurrence – meaning the cancer returned – as compared to partial nephrectomy patients. Traditional Open Surgery – Kidney surgery is traditionally performed using an open approach, meaning doctors must make a large incision in the abdomen. Another approach is conventional laparoscopic surgery. It is less invasive, but limits the doctor’s dexterity, vision and control, compared to open surgery.

Laparoscopic Surgery 

With laparoscopic surgery, the surgeon makes several small incisions, instead of the one large incision. The surgeon also uses telescoping equipment to view and remove the bladder. This surgery may take longer, but it is typically less painful during recovery. Because of the long-handled instruments used in laparoscopic surgery, there are certain limitations during delicate or complex operations.