Patients receiving radical nephrectomy at risk for chronic kidney disease

Twenty-six percent of patients in this retrospective study had pre-existing chronic kidney disease prior to surgery.

Issue: October 1, 2006

Radical nephrectomy could lead to chronic kidney disease and may no longer be the preferred treatment for small, renal cortical tumors, according to a retrospective cohort study of 662 patients.

Patients who received partial nephrectomy developed chronic kidney disease at a rate one-third lower than patients who received radical nephrectomy, according to researchers. The three-year probability of staying free of chronic kidney disease was 80% for patients who received partial nephrectomy compared with 35% for patients who underwent a radical nephrectomy. Radical nephrectomy was shown to be a significant risk factor for developing chronic kidney disease.

“The results of our study demonstrated that prior to surgery, the baseline kidney function of patients with small kidney tumors was significantly lower than previously recognized,” said lead researcher William C. Huang, MD, member of the department of urology at Memorial Sloan-Kettering Cancer Center in New York. “Patients who undergo a radical nephrectomy, the most common treatment for small kidney tumors, are at significantly greater risk for the development of chronic kidney disease after surgery compared with those who undergo a partial nephrectomy.”

Results

All patients had normal serum creatinine and two otherwise healthy kidneys. They underwent either partial or radical nephrectomy for a solitary, renal cortical tumor (less than 4 cm). Researchers defined chronic kidney disease in patients who received a partial nephrectomy and who had a glomerular filtration rate (GFR) lower than 60 mL/min per 1.73 m², and in patients who received a radical nephrectomy and who had a GFR lower than 45 mL/min per 1.73 m². Researchers identified chronic kidney disease in patients before and after surgery by defining CKD as a GFR less than 60. Additionally, they analyzed the new onset of GFR less than 45 in patients following surgery as a separate endpoint.

Twenty-six percent of patients (n=171) had pre-existing chronic kidney disease prior to surgery, according to the study. After surgery, the three-year probability of freedom from new onset of GFR lower than 60 mL/min per 1.73 m² was 80% (95% CI, 73-85; P<.0001) after partial nephrectomy, and 35% (95% CI, 28-43; P<.0001) after radical nephrectomy; corresponding values for GFRs lower than 45 mL/min per 1.73 m² were 95% (95% CI, 91-98; P<.0001) and 64% (95% CI, 56-70; P<.0001), respectively.

A multivariable analysis showed that radical nephrectomy remained an independent risk factor for patients developing new onset of GFR lower than 60 mL/min per 1.73 m² (HR 3.82; 95% CI, 2.75-5.32; P<.0001) and 45 mL/min per 1.73 m² (HR 11.8; 95% CI 6.24-22.4; P<.0001).

The study appeared in the September issue of The Lancet Oncology.

Prevalence of nephrectomy

Paul Russo, MD [photo]
Paul Russo

Although partial nephrectomies account for 30% to 65% of all kidney surgeries performed in tertiary care centers in the United States, the latest analysis from the Nationwide Inpatient Sample reported in the journal Urology indicated that 92.5% of all kidney cancer surgeries in the United States from 1998 to 2002 were radical nephrectomies.

“Evidence has accumulated from our center and elsewhere that partial nephrectomy provides effective local tumor control and equivalent survival rates to that of radical nephrectomy for small tumors,” said Paul Russo, MD, member of the department of urology at Memorial Sloan-Kettering and senior researcher. “However, while approximately 70% of kidney tumor operations at MSKCC are partial nephrectomies, national databases from the United States and abroad suggest that greater than 80% of patients may be unnecessarily undergoing the more radical surgery to remove the entire kidney, even for small renal tumors. One explanation may be that partial nephrectomy is a more complex surgical procedure.”

Complex procedure

Physicians at major American medical centers are comfortable performing a partial nephrectomy in 60% to 70% of operations on small renal tumors, according to Russo. However, across the country and around the world, partial nephrectomy is performed less than 20% of the time. This may be due to a lack of training in partial nephrectomy or the outdated belief that the kidney is a “dispensable” organ and that radical nephrectomy is the best option.

The decision to opt for partial nephrectomy is supported by a wealth of data. Most importantly, most small kidney tumors do not pose a significant health risk: 20% of such tumors are benign (ie, oncocytoma or angiomyolipoma), Russo said. Another 25% are indolent cancers with limited metastatic potential (chromophobe or papillary) and 54% are the most potentially metastatic clear-cell variant that can metastasize, but it is uncommon when they are smaller than 4 cm.

In the last six years, research has shown that future renal function could be compromised by radical nephrectomy. Whether chronic kidney disease was “earned” by hypertension, smoking, diabetes, etc., or accentuated or induced by radical nephrectomy, the condition could have a detrimental effect on the overall health of the patient, Russo said. Patients with chronic kidney disease are also susceptible to cardiovascular disease, which gives surgeons even more incentive to spare as much of the organ as possible.

“I think our data in 700 patients is compelling and is similar to that of other high volume kidney centers such as Mayo and Cleveland Clinics,” Russo said in an interview. “Radical nephrectomy should not be liberally applied to small renal tumors and partial nephrectomy should be done whenever technically possible. I do not believe a formal randomized clinical trial would be the right thing to do since the wealth of information available so strongly supports partial nephrectomy for the small renal mass.” – by Mark Palacio

For more information:

Huang WC, Levey AS, Serio AM, et al. Chronic kidney disease after nephrectomy in patients with renal cortical tumours: a retrospective cohort study. Lancet Oncol. 2006;7:735-740.