What is Kidney Cancer?

May 28, 2021

Kidney cancer is a cancer that starts in the kidneys, and begins when cells there begin to grow abnormally. Tumors may be benign (non-cancerous) or malignant (cancerous). The most common non-cancerous kidney tumor is a fluid-filled area called a cyst. Simple cysts are benign and do not progress to cancer. Solid kidney tumors are cancerous more than 80% of the time. The most common kidney cancer is called renal cell carcinoma. Approximately 9 out of 10 kidney cancers are renal cell carcinoma (RCC). There are several subtypes of RCC, which are identified based on how the cancer cells look under a microscope. Knowing the subtype of RCC can be a factor in deciding treatment.

In the U.S., approximately 2% of all cancers arise from the kidney. Each year, kidney cancer is diagnosed in approximately 52,000 Americans. Kidney cancer is about twice as common in males than females and is usually diagnosed between the ages of 50 and 70 years. With early diagnosis and treatment kidney cancer can be cured, and survival rates for patients with kidney cancer range from 79-100%.

Most people have two functional kidneys. The kidneys produce urine that drains through narrow tubes (ureters) into the bladder. The kidneys are located in each flank and protected by the back muscles and ribcage. The kidney is the main filter of the body and performs many bodily functions, such as controlling fluid balance, regulating electrolytes, preventing acid buildup, eliminating waste products, producing urine, and regulating blood pressure. The kidney also manufactures hormones, which aids in the production of red blood cells.

When the kidneys are damaged, or a significant portion of kidney tissue is removed due to cancer, the normal functions of the kidneys may be impaired. In most cases, mild to moderate impairment causes very minor problems. In cases where kidney function is severely impaired, dialysis may be required.

There are some known links that may increase the risk of developing kidney cancer:
-Workplace exposure to substances like cadmium, herbicides, organic solvents and trichloroethylene
-Race: African Americans, American Indians, Alaska Natives are at higher risk
-Chronic kidney failure and/or dialysis
-Diet with high caloric intake or high in fried/sautéed meat
-Other hereditary or genetic risk factors

Oftentimes many cancerous kidney tumors do not produce symptoms. Instead they are found incidentally on imaging when evaluating for an unrelated problem or during a routine screening for those at high risk. However, more advanced cancerous tumors may compress, stretch and invade the structures near the kidney, causing pain in the flank, abdomen or back. A mass may be felt, and blood in the urine (either visible or seen through a microscope) is also typical. Currently, however, there are no blood or urine tests available that directly detect the presence of kidney tumors. If the cancer has spread to other parts of the body, then shortness of breath, coughing up blood, bone pain or bone fracture may occur. Neurologic functions may change if it has reached the brain.

When a kidney tumor is suspected, an imaging study is obtained. The initial imaging study is usually a renal ultrasound or CT scan of the abdomen and pelvis. In some cases, a combination of imaging studies may be required to completely evaluate the tumor. If cancer is suspected, the patient is then further evaluated to determine if the cancer has spread beyond the kidney using additional imaging and blood tests.

Be sure to check out our next blog that explores treatment options for kidney cancer.

If you have any concerns about kidney cancer or have been diagnosed and want to learn more about treatment options, you can schedule a consultation with a provider at Austin Urology Institute by calling 512.694.888,