Kidney cancer (also called renal cancer) is among the 10 most common cancers in men and in women. The American Cancer Society estimates that in 2015, 61,560 new cases of kidney cancer, 38,270 in men and 23,290 in women, will be diagnosed, and 14,080 patients will die from this disease in the United States. The lifetime risk for kidney cancer is about 1 in 63 (1.6%); the risk is higher in men than in women.
Certain factors can increase the risk for kidney cancer. Perhaps the biggest risk factor is increasing age: being older than age 40 puts an individual at greater risk for kidney cancer. Certain lifestyle behaviors and medical conditions are also believed to increase the risk for kidney cancer. These include:
- Cigarette smoking
- Exposure to environmental substances, such as asbestos, cadmium, benzene, and herbicides
- High blood pressure
- Kidney disease and long-term dialysis
People with a strong family history of kidney cancer, especially siblings, are at higher risk for this cancer. African Americans and American Indians/Alaska Natives have slightly higher rates of kidney cancer than Caucasians.
There are genetic syndromes that run in families, such as defects (mutations) in the VHL, MET, FH, FLCN, SDHB, and SDHD genes, that increase the risk for kidney cancer. Defects in the SDHB and SDHD genes can cause Cowden-like syndrome, which puts people at greater risk for breast, thyroid, and kidney cancers.
Therefore, it is important to let your physician know if anyone else in your family has been diagnosed with cancer.
Early kidney cancers do not usually cause any symptoms, but as the tumors grow larger, symptoms may appear. Possible signs and symptoms of kidney cancer include blood in the urine (hematuria); a lump or mass on the side or lower back; lower back pain on one side, not related to an injury; fatigue; weight loss; anemia; and swelling of the ankles or legs.
Types of Kidney Cancer
Renal-cell carcinoma (cancer in the lining of the tubules of the kidney) is the most common type of kidney cancer. Approximately 9 in 10 kidney cancers are renal-cell carcinoma. Renal-cell carcinoma is divided into several subtypes, including clear cell renal-cell carcinoma; papillary renal-cell carcinoma; and chromophobe renal-cell carcinoma.
Other types of kidney cancers include transitional-cell carcinoma (urothelial), Wilms tumor, and renal sarcoma.
At this time, there is no screening used in the general population to reduce the risk for kidney cancer. The diagnosis of kidney cancer is made with a physical exam; health history; laboratory tests, including blood work and urinalysis; and imaging tests, including ultrasound, intravenous pyelogram, CT scan, MRI, and renal arteriogram.
Once a diagnosis is confirmed and the staging is complete, surgeons and oncologists can initiate the treatment plan. The types of treatment for kidney cancer include surgical removal of the kidney (nephrectomy), cryotherapy and radiofrequency ablation, radiation therapy, chemotherapy, and targeted therapy.
Surgery is the main treatment for most kidney cancers.
Because the kidneys are not very sensitive to radiation, radiation therapy is generally used for patients who cannot tolerate surgery or for palliative control of symptoms related to the spread of cancer.
As researchers have learned more about what makes kidney cancer cells different from normal cells, newer drugs have been developed that “target” the specific cancer cells. These targeted drugs block the growth of new blood vessels that nourish cancer cells (angiogenesis) or important proteins (tyrosine kinases) that help the cancer cells to grow and divide.
Targeted drugs, such as Nexavar (sorafenib), Sutent (sunitinib), and Avastin (bevacizumab), block the formation of new blood vessels in the cancer cells. Torisel (temsirolimus), Votrient (pazopanib), and Inlyta (axitinib) are targeted drugs that block tyrosine kinase proteins.
Clinical trials are being conducted to further study targeted drugs, as well as immunotherapy (drugs that use the body’s own immune system to fight cancer) for the treatment of kidney cancer.