Radical Nephrectomy May Be Overkill for Small, Renal Cortical Tumors

NEW YORK SEP 08, 2006 (Reuters Health) - As a treatment for small, renal cortical tumors, radical nephrectomy increases the risk of chronic kidney disease compared with partial nephrectomy, according to a new report.

This finding, coupled with previous reports showing comparable oncologic control with both surgeries, suggests that radical nephrectomy may entail excessive morbidity for treating these small tumors, which are typically detected incidentally on abdominal imaging performed for other reasons.  These tumors are thought to account for up to 70% of all diagnosed renal masses.   

"We hope that surgeons who read this article will think long term, beyond cancer survival," senior author Dr. Paul Russo, from Memorial Sloan-Kettering Cancer Center in New York, told Reuters Health. 

"The cancer threat of small, renal cortical tumors is minimal at most and the vast majority of patients will survive with treatment.  So, the focus is now on improving long-term outcomes," such as kidney function, he added.  

The new study, which is reported in the September issue of The Lancet Oncology, involved 662 patients who underwent partial or radical nephrectomy for a small renal cortical tumor, defined as one no greater than 4 cm in diameter, at Memorial Sloan-Kettering between 1989 and 2005.  All of the subjects had a normal serum creatinine level and two healthy kidneys before surgery.

Glomerular filtration rate (GFR) before and after surgery was estimated using a validated measure called the abbreviated Modification in Diet and Renal Disease Study equation. 

Prior to surgery, 26% of patients met GFR criteria for chronic kidney disease, the report indicates. 

At 3 years post surgery, patients treated with partial nephrectomy were more likely to remain free of kidney disease than those treated with radical nephrectomy (p < 0.0001).  Depending on the GFR definition of kidney disease, the percentage of disease-free subjects ranged from 80% to 95% in the partial nephrectomy group compared with 35% to 64% in the radical nephrectomy group.    

On multivariate analysis, radical nephrectomy was an independent risk factor for chronic kidney disease, raising the risk by up to 11.8-fold. 

"Roughly, 70% of our nephrectomies are partial," which is in sharp contrast to what is seen nationally, Dr. Russo noted.  "Even for small kidney tumors, 80% of patients across the country are still getting radical nephrectomy." 

Dr. Russo believes the difference may relate to a lack of experience.  Partial nephrectomy is a more technically demanding procedure than radical nephrectomy "and many surgeons do not have a high enough caseload to feel comfortable doing it," he added.   

SOURCE;

• Lancet Oncology 2006.