Overview of the Kidneys
The kidneys are two bean-shaped organs fixed to the back wall of the abdominal cavity. One kidney is to the left and the other is to the right of the backbone. Both are protected by the lower ribcage. The kidneys' function is to filter the blood and eliminate the body of excess fluid, salt and waste products. Filtered blood (urine) leaves the kidney through a long tubular structure called a ureter. The ureters connect the kidneys to the bladder. Urine is stored in the bladder until urination.
All of the important functions of kidney can be handled with one kidney and that's why many people are living normal healthy lives with just one kidney. Kidney cancers may start within the kidney (primary) or have spread from another organ/source. Primary kidney cancers may include renal cell carcinoma, transitional cell carcinoma (renal pelvic tumor), sarcomas and collecting duct tumors.
First & Foremost
Kidney cancers tend to grow impressively before they can be diagnosed based on symptoms. Fortunately, the increased use of imaging techniques such as CT scans and ultrasound have allowed incidental detection of kidney tumors at an earlier stage. Additionally, a better evaluation of growths within the kidney are possible with improved CT scanning techniques and MRI scans as well. Taken together, smaller tumors can now more commonly be treated by partial nephrectomy (removal of just the tumor and a small rim of normal kidney tissue) instead of taking out the entire kidney.
Better molecular techniques have allowed more accurate identification of the source of kidney tumors, allowing better classification of kidney cancers. This new classification will allow better management approaches as well as to help direct newer treatments for kidney (renal cell) cancers. Genetic evaluation has also helped to identify the causes of some kidney cancers, especially those that run in families or occur in conjunction with the Von Hippel-Lindau syndrome.
Unfortunately, only limited treatments still exist for kidney cancers that have spread beyond the kidney. Immune based treatments such as IL-2 (interleukin-2) are able to result in suppression and remission for some kidney cancers. Many kidney cancers appear to reject chemotherapy drugs by "ejecting" them out of cancer cells with a protein referred to as the MDR (multi-drug resistance) gene. Radiation also has limited activity in kidney cancers. A number of experimental approaches to better target and attack kidney cancers are being developed.
One very exciting prospect for treatment of kidney cancers is the use of monoclonal antibodies, which act as "magic bullets" to attack surface elements on kidney cancer cells. These antibodies have been worked on extensively by Dr. Neil Bander of the Department of Urology at Cornell. This approach has been used to image where the cancer is in the body. Future developments will likely result in monoclonal antibody-based techniques for destruction of kidney cancers.
In the past, RCCs were diagnosed only after they have become quite large or symptoms of flank pain, blood in the urine, or palpable mass in the abdomen developed. But fortunately, most RCC are now found incidentally (during evaluation of unrelated medical problems) by imaging studies such as ultrasound, CAT scan, or MRI.
It is expected that there will be about 30,000 new cases of kidney cancer (17,800 in men and 12,200 in women) in 1999 in the United States. In 1999 about 11,900 people (7,200 men and 4,700 women) will die from this disease. RCC accounts for about 85% of all kidney tumors.
About one-third of patients are found to already have developed metastases by the time their RCC is diagnosed. The five-year survival rate is about 40%-45% for all RCC stages combined.
The 5-year survival rate refers to the percent of patients who live at least 5 years after their cancer is diagnosed. Five-year relative survival rates exclude from the calculations patients dying of other diseases, and are considered to be a more accurate way to describe the prognosis for patients with a particular type and stage of cancer. Of course, 5-year survival rates are based on patients diagnosed and initially treated more than 5 years ago. Improvements in treatment often result in a more favorable outlook for recently diagnosed patients.
Kidney Cancer - Renal Cell Carcinoma (RCC)
RCC is the most common type of kidney cancer. RCC begins small and grows larger over time, like many other cancers. Based on limited observations, renal cancers appear to grow approximately 1 cm (1/2 inch) in diameter per year. RCC usually grows as a single mass.