Nephron-Sparing Surgery Leads to Better Functional Outcomes for Large Renal Tumors

Nephron-sparing surgery is more effective than radical nephrectomy for preserving long-term renal function in patients with renal tumors >4 cm, a German team has found. Importantly, nephron-sparing surgery seems to be the superior approach, irrespective of the patient’s age.

Frederik C. Roos, MD, from Johannes Gutenberg University in Mainz, Germany, and colleagues examined functional outcome in patients undergoing elective treatment for unilateral renal tumors >4 cm. The study included 81 “younger” patients who were aged <55 years and 85 “older” patients aged >65 years.

Overall, 84.5% of younger and 75.8% of older patients maintained good long-term renal function with nephron-sparing surgery. The researchers pointed out that this is important given that loss of renal function is associated with increased cardiac mortality, decreased physiological reserves in multiple organ systems, and a higher incidence of cardiovascular disease.

Renal cell carcinoma primarily affects individuals in their 60s and 70s. Nephron-sparing surgery has been the mainstay of treatment in patients presenting with renal tumors ≤4 cm and is recommended for cT1b lesions at high-volume cancer centers. There are, however, limited data on oncologic or perioperative outcomes in elderly patients undergoing elective nephronsparing surgery for renal tumors >4 cm compared with radical nephrectomy.

Roos and colleagues believed that open radical nephrectomy was overused in older patients in order to minimize operating time, even in patients with small tumors (cT1a), and thus decided to examine whether elderly patients would benefit from nephron-sparing surgery. The median length of follow-up in their study was 5.69 years for younger patients and 5.48 years for older patients. Renal function and perioperative morbidity were co-primary endpoints. Overall survival (OS) was a secondary endpoint.

When deciding between radical nephrectomy and nephronsparing surgery in renal tumors >4 cm, clinicians need to carefully consider tumor characteristics, comorbidities, biological age, and the patient’s own wishes.

Results showed that the incidence of new onset of chronic kidney disease in younger patients was 31.1% after radical nephrectomy and 15.5% after nephron-sparing surgery. The corresponding figures in older patients were 50.9% and 24.2%, respectively. Chronic kidney disease was defined as a glomerular filtration rate <60 mL/min/1.73m². Complications occurred in 34.5% of younger patients and 25.8% of older patients (P = .656).

OS did not differ significantly between the 2 procedures in young (P = .655) and older patients (P = .058). The authors suggested that the lack of a difference in OS between younger and older patients may be due to “an underpowered statistical analysis for OS and a lack of follow-up in both age groups mainly after radical nephrectomy.”

Roos and associates emphasized that when deciding between radical nephrectomy and nephronsparing surgery in renal tumors >4 cm, clinicians need to carefully consider multiple factors. These include tumor characteristics, comorbidities, biological age, and the patient’s own wishes and social support. If nephron-sparing surgery is deemed feasible in a given patient, it is preferable to radical nephrectomy for both younger and older patients.

Eventually, minimally invasive techniques, including robotassisted laparoscopy and thermal ablation, may have expanded indications to include the treatment of patients with more severe comorbidities and tumors >4 cm, they added.

Roos FC, Brenner W, Jäger W, et al. Perioperative morbidity and renal function in young and elderly patients undergoing elective nephron-sparing surgery or radical nephrectomy for renal tumours larger than 4 cm. BJU Int. 2011. Feb;107(4):554-61. doi: 10.1111/j.1464- 410X.2010.09516.x. Epub ahead of print, August 12, 2010.