It is important to realize that with timely diagnosis and treatment, kidney cancer can be cured. If found early, the survival rate for patients with kidney cancer ranges from 79 to 100 percent. More than 100,000 survivors of kidney cancer are alive in the United States today. The following information addresses the most common questions about kidney tumors and serves as a supplement to the discussion that you have with your physician.
What is a kidney tumor?
A kidney tumor is an abnormal growth within 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 lesion is a fluid-filled area called a cyst. Simple cysts are benign and have a typical appearance on imaging studies. They do not progress to cancer and usually require no follow-up or treatment. Solid kidney tumors can be benign, but are cancerous more than 80 percent of the time.
What are some facts about kidney cancer?
In the United States, 2 percent of all cancers arise from the kidney. In 2014, it is estimated that over 63,000 people will be diagnosed of kidney cancer. It is also estimated that over 13,000 people will die from kidney cancer. Kidney cancer is slightly more common in males and is usually diagnosed between the ages of 50 and 70 years. The most common kidney cancer is called renal cell carcinoma.
What risk factors are associated with kidney cancer?
The following associations may increase the risk of developing kidney cancer:
• family history of kidney cancer
• chronic kidney failure and/or dialysis
• diet with high caloric intake or fried/sauteed meat
• Von Hippel-Lindau syndrome
• tuberous sclerosis
What are the symptoms for kidney cancer?
Many kidney tumors do not produce symptoms, but may be detected incidentally during the evaluation of an unrelated problem or during routine screening for people who are in high-risk categories (e.g. Von Hippel-Lindau disease, tuberous sclerosis). Compression, stretching and invasion of structures near the kidney may cause pain (in the flank, abdomen or back), palpablemass, and blood in the urine (microscopic or grossly visible). If cancer spreads (metastasizes) beyond the kidney, symptoms depend upon the involved organ. Shortness of breath or coughing up blood may occur when cancer is in the lung, bone pain or fracture may occur when cancer is in the bone and neurologic symptoms may occur when cancer is in the brain. In some cases, the cancer causes associated clinical or laboratory abnormalities calledparaneoplastic syndromes. These syndromes are observed in approximately 20 percent of patients with kidney cancer 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. Laboratory findings include elevated red blood cellsedimentation rate, low blood count (anemia), high calcium level in the blood, abnormal liver function tests, elevated alkaline phosphatase in the blood, and high blood count. In many cases, the paraneoplastic syndrome resolves after the cancer is removed.
How is kidney cancer diagnosed?
Unfortunately, there are no blood or urine tests that directly detect the presence of kidney tumors.
When a kidney tumor is suspected, a kidney imaging study is obtained. The initial imaging study is usually an ultrasound or CT scan. In some cases, a combination of imaging studies may be required to completely evaluate the tumor. If cancer is suspected, the patient should be evaluated to see if the cancer has spread beyond the kidney (metastasis). An evaluation for metastasis includes an abdominal CT scan or MRI, chest X-ray and blood tests. A bone scan is also recommended if the patient has bone pain, recent bone fractures, or certain abnormalities on their blood tests. Additional tests may be obtained when indicated. Kidney cancer has the tendency to grow into the renal vein and vena cava. The portion of the cancer that extends into these veins is called “tumor thrombus.” Imaging studies, particularly CT or MRI, can help determine if tumor thrombus is present.
What are the treatment options for tumors that appear confined to the kidney?
When the tumor appears confined to the kidney (a “localized” tumor), there are three main treatment options: tumor removal, tumor ablation and surveillance. Chemotherapy, hormone therapy and radiation therapy are not effective treatments for kidney cancer.