by Jody A. Charnow, Editor, Renal and Urology News
February 9, 2015

Patients with renal cell carcinoma (RCC) are at lower risk of end-stage renal disease (ESRD) requiring renal replacement therapy (dialysis or transplant) if they undergo partial rather than radical nephrectomy, a new study suggests.

The population-based, retrospective cohort study of 11,937 RCC patients who underwent radical nephrectomy (RN) or partial nephrectomy (PN) during 1995–2010. Researchers divided subjects into an early cohort (those who had surgery from 1995–2002) and a modern cohort (those who had surgery from 2003–2010).

In the full cohort, the study revealed no significant association between type of surgery and ESRD rate, but PN was associated with a significant 52% decreased risk of chronic kidney disease (CKD).

In the modern cohort, PN recipients had a significant 56% decreased risk of ESRD requiring renal replacement therapy (RRT) compared with patients who underwent RN, after a median follow-up of 41 months, researchers led by Stanley A. Yap, MD, of the University of California Davis in Sacramento, reported online ahead of print in BJU International. In a propensity score analysis, which the investigators used to decrease bias and to control for differences between treatment groups, PN was associated with a significant 53% decreased risk of ESRD.

In the modern cohort, the RN and PN patients had a median time of progression to ESRD of 5 months and 16 months, respectively.

“Although it is well-known that RN is associated with more CKD than PN, we provide the first direct evidence that PN is associated with less ESRD requiring renal replacement therapy than RN in a modern cohort of patients with RCC,” the authors concluded.

They also stated, “The distinction of a modern cohort is important, as it consists of patients that encompass a more accurate representation of current practice,” the investigators wrote. “During earlier years of the present cohort, PN had yet to gain widespread use and acceptance.”

Of the 11,937 patients in the full cohort, 9,830 (82%) and 2,107 (18%) underwent RN or PN, respectively. Overall, during the postoperative period, ESRD developed in 292 patients (2.5%). The group included 47 patients in the PN group (2.2%) compared with 245 patients in the RN group (2.5%). The mean time to progression to ESRD was 19 months and 38 months for patients in the RN and PN groups, respectively.

The early cohort included 4,297 RN patients and 360 PN patients, which had unadjusted rates of ESRD of 3.7% and 8.6%, respectively. The modern cohort included 5,484 (76%) and 1,746 (24%) patients who underwent RN and PN, respectively, and their unadjusted rates of ESRD were 1.6% and 0.9, respectively.

Dr. Yap and his colleagues noted that their study was limited by a lack of pathological and staging data. Patients initially presenting with T1a tumors (4 cm or less) represent an important subpopulation in which it is considered a standard of care to perform PN instead of RN, they pointed. “The major limitation of our pathological data is the inability to isolate this population.”

This article originally printed in the March 2015 Issue of Renal And Urology News