Surgery is often the first step in treating kidney cancer, and new data, which contradict earlier research, questions whether removing only the tumor (partial nephrectomy) is better than removing the entire kidney (radical nephrectomy).
The strong trend for the past decade has been toward a partial resection in the case of smaller cancers. This was based on several earlier studies that suggested it is best to save as much kidney tissue as possible, with the goals of preserving kidney function and reducing the likelihood of kidney failure over the long term. Many physicians inferred that a radical nephrectomy would be worse for patients with kidney cancer, since they were concerned that even mild or moderate dysfunction in the remaining kidney could lead to an earlier death.
However, a study by the University of Rochester Medical Center in New York found that losing a whole kidney to surgery does not translate to poorer outcomes for patients. Overall survival was not improved in patients who had a partial nephrectomy. The study was published in European Urology (2013; doi: 10.1016/j.eururo.2013.06.044).
“Our data appears to seriously question the assumption that by saving kidney tissue, we are helping patients avoid future kidney failure,” said Edward Messing, MD, chair of Urology at URMC. “It may be that losing kidney tissue from surgery is not the same as losing kidney function from medical diseases like diabetes or hypertension.”
This study analyzed renal dysfunction based on trial data from over 500 patients registered for the European Organization for Research and Treatment of Cancer randomized trial from 1992 to 2003. The patients all had been diagnosed with a small kidney cancer and had a normal-functioning second kidney. The trial randomized 255 patients to treatment with a partial nephrectomy and 259 to treatment with a radical nephrectomy.
Each patient’s kidney function was analyzed for a median of seven years after surgery, and the cohort was followed for about nine years. At the median follow-up of 6.7 years, the frequency of moderate kidney dysfunction was 20% lower among the patients who had received a partial nephrectomy, compared with those who were randomized to a radical nephrectomy. However, the better overall kidney function in the partial nephrectomy group did not result in improved survival. At the last follow-up point of about nine years, the study found that fewer deaths had occurred in the radical-nephrectomy group.
Both groups had similar rates of kidney failure, about 1.5%. Messing stated that this was a bit surprising, as it demonstrated that patients in the radical-nephrectomy group who had initially suffered a mild or moderate degree of kidney dysfunction did not see their condition progress to kidney failure. When choosing a surgery, he explained that it is important to consider the best option for removing the cancer in the broader context of other medical conditions that impact kidneys.