Feb. 13, 2008 -- Are some people unnecessarily losing a kidney? That's the question raised by a new study that suggests that people with small kidney tumors are typically referred for surgical removal of the entire kidney even though kidney-conserving surgery is just as effective.
Researcher William Huang, MD, assistant professor of urologic oncology at New York University School of Medicine, says that due to their small size, over half of newly diagnosed kidney tumors are amenable to partial nephrectomy. Partial nephrectomy involves removal of the tumor and surrounding tissue, sparing the rest of the kidney.
Partial nephrectomy is just as likely to cure small kidney tumors -- "those less than 4 centimeters, and in some cases even up to 7 centimeters, in diameter" -- as removal of the entire affected kidney, Huang says. "Despite this, four in five patients with small kidney tumors are having their whole kidney removed.
"Just as lumpectomy can be less invasive but as effective as mastectomy for treating breast cancer, people with kidney cancer should be aware that partial nephrectomy is not only an option, but may be a better option than radical nephrectomy in many circumstances," Huang says.
Preserving Kidney Function
Howard M. Sandler, MD, a radiation oncologist at the University of Michigan who moderated a news briefing to discuss the findings, agrees that kidney-conserving surgery should be offered whenever possible.
That's because a partial nephrectomy can preserve the kidney and long-term kidney function, he says
While you can live with one kidney, Sandler notes that all our organs naturally lose function as we age.
"You'll run out of function earlier if you only have one kidney," he tells WebMD.
Huang says the incidence of kidney tumors is rapidly rising, with a 3% increase each year for the past 20 years; about 51,000 new kidney tumors will be diagnosed in the U.S. in 2008.
Huang and colleagues combed through the NCI's Surveillance, Epidemiology and End Results (SEER) database from 1995 to 2002, comparing the characteristics of 2,547 patients with small renal tumors who had radical nephrectomy and 556 who had partial nephrectomy. A radical nephrectomy is surgical removal of the whole kidney.
The findings are being presented later this week at the Genitourinary Cancers Symposium in San Francisco.
Results showed that older people and people who had suffered a stroke were each about 40% more likely to have their whole kidney removed. Women were about 30% more likely to undergo radical nephrectomy than men.
Huang speculates that some surgeons may prefer to perform a radical nephrectomy because it is technically less challenging to perform and has a lower risk of complications. This may make the operation particularly appealing for older people and those with other medical conditions, he says.
The reason for the gender bias is less clear, Huang says.
Results also showed people treated during the later part of the study period were more likely to have kidney-conserving surgery than those treated earlier. This suggests partial nephrectomy may be slowly catching on, Huang says.