The American Cancer Society’s most recent estimates for kidney cancer in the United States are about 76,0800 new cases of kidney cancer (48,780 in men and 27,300 in women) will be diagnosed. Americans are diagnosed with kidney cancer every year, representing three percent of all adult cancers. Kidney cancer, referred to as renal cell carcinoma, occurs when kidney cells begin to grow out of control.
There are several different subtypes of kidney cancer: clear cell, papillary, chromaphobe, sarcomatoid, and urothelial, among others. Treatments vary depending on the type.
Kidney cancer, in its early stages, is quite “silent,” in that it causes no symptoms at all. As a kidney cancer grows larger, it can cause symptoms, such as blood in the urine, pain in the flank, and a bulge in the flank or abdomen. Less common symptoms include low blood count (anemia), high blood count, elevated blood calcium, fever, loss of appetite, weight loss, etc. Kidney cancer can spread to other organs, primarily to the bones, liver or lungs. Once it has spread, it is much more difficult to cure.
Fortunately, the vast majority of kidney cancers are discovered at early stages, due to the frequent use of abdominal CT scans and abdominal Ultrasound exams. More than 85 percent of patients with kidney cancer are diagnosed when the cancer is 5 cm (2 inches) or less. In general, the smaller the size of the cancer at the time of discovery, the greater the chance of cure. The cure rate for these small cancers is greater than 95 percent when treated appropriately.
The best test to diagnose kidney cancer is the computed tomography scan (CT scan) of the abdomen. This is often combined with an ultrasound exam. These imaging studies are 99 percent accurate in establishing the diagnosis of a solid mass in the kidney, and 95 percent of solid masses are kidney cancer. Only 5 percent are benign tumors, called oncocytoma.
Another scan which is occasionally ordered is MRI (magnetic resonance imaging), which can help to make the diagnosis in difficult cases, and determine if it is invading other structures. These imaging tests are so accurate that a biopsy is rarely indicated, and often contraindicated, due to the risk of bleeding and spread of the cancer cells.
Tests are often ordered to determine if there is any spread of the cancer to other organs. These imaging studies include chest X-ray, CT scan of the chest, and bone scan. The role of PET scans (positron emission tomography) is still being studied.
Treatment options for kidney cancer renal cell carcinoma) include:
The primary treatment of kidney cancer is either traditional surgery or robotic surgery to remove it before it has spread. Kidney cancer is not very responsive to radiation therapy or standard chemotherapy, so these options play a very limited role.
Large cancers are treated my removing the entire kidney (radical nephrectomy). Since 85 percent of kidney cancers are now discovered when they are small (less than 5 cm or 2 inches), most of these cancers can be treated by just removing the tumor and preserving the rest of the kidney (partial nephrectomy, cryoablation, radiofrequency ablation).
A partial nephrectomy leads to better overall kidney function compared to radical nephrectomy when treating these small tumors. The cure rate for partial nephrectomy has been shown to be just as good as a radical nephrectomy.