Nephron Sparing Surgery for Large Renal Tumors: Always, Sometimes, or Never?

Riccardo Autorino, MD, PhD, FEBU, presented “Nephron Sparing Surgery for Large Renal Tumors: Always, Sometimes, or Never?” at the Jackson Hole Seminars on February 7, 2018 in Jackson Hole, Wyoming.

How to cite: Autorino, Riccardo. “Nephron Sparing Surgery for Large Renal Tumors: Always, Sometimes, or Never?”   February 7, 2018. Accessed Nov 2024. https://grandroundsinurology.com/Nephron-Sparing-Surgery-for-Large-Renal-Tumors/

Nephron Sparing Surgery for Large Renal Tumors: Always, Sometimes, or Never?

Summary:

Riccardo Autorino, MD, PhD, summarizes the current EAU, AUA, and ASCO recommendations regarding partial and radical nephrectomies, the effect robotic surgery has had in this clinical area, and whether or not nephron sparing surgery is a beneficial and safe method for the management of large renal masses.

Current EAU, AUA, and ASCO Indications

Kidney cancer management guidelines, like any those for other cancerous disease, vary based upon stage of disease. Across European Association of Urology (EAU), American Urological Association (AUA), and American Society of Clinical Oncology (ASCO) guidelines, recommendations currently indicate nephron sparing surgery for small renal masses, or whenever technically feasible. The term “small renal tumors” encompasses clinical stage T1 tumors smaller than four centimeters. It also refers to localized T1 tumors between four and seven centimeters.

On the other hand, radical nephrectomy (RN) is still the standard option for clinical stage T2 masses, tumors larger than seven centimeters, and those that pose challenges in terms of surgical planning.

Robotic Surgery’s Role in the Rise of Partial Nephrectomies in Recent Years

Over the course of recent years, trends in the use of partial nephrectomies have increased. But, there is still some room for that trend to grow even more. A study published in Urologic Oncology: Seminars and Original Investigations revealed the use of partial nephrectomy (PN) is still very low in high risk disease, especially in T1B tumors.

Furthermore, Peter Schulam, MD, PhD, and a research group observed data from the NIS database and over 20,000 cases. The study’s objective was to identify which parameters impacted decisions to use PN versus RN. A significant trend the study highlighted was that hospitals that owned robotic systems tended to perform a relatively high number of partial nephrectomies. Robotic surgery provides a better visual aide through tools such as ultrasound. It generally allows clinicians to perform PN, even in complex-mass cases, with more technical ease than a laparoscopic method.

Nephron Sparing Surgery in the Small Mass Setting

Currently, it is widely accepted that PN should be the preferred option for smaller masses, as opposed to RN. Several studies show that both methods result in similar oncological outcomes, but PN offers a better recovery of renal function, and, correspondingly, a better survival.

While the the well-known EORTC trial, which ran from 1992- 2003, concluded that patients in a PN arm had a slightly higher complication rate and a worse 10 year survival rate then the RN arm, the study was subject to biases and limitations. On the other hand, Simon Kim, MD, MPH, led a meta-analyses in 2012. It showed that PN correlated with a reduction in all-cause mortality, cancer-specific mortality, and risk of severe chronic kidney disease (CKD). Furthermore, a more recent meta-analysis, which looked at functional cardiovascular outcomes in 26 studies, confirmed that PN reduced the postoperative risk of new-onset CKD.

Nephron Sparing Surgery for Large Renal Masses

Dr. Autorino and his research group published a meta-analysis in April of 2017. It looked at 21 case-controlled studies and over 11,000 patients. They ultimately found that RN implied less risk of complications. However, as is the case with small masses, PN allows for better preservation of renal function. It should be noted that this meta-analyses excluded randomized studies. Therefore, selection biases may have affected these results.

One randomized study, led by Ryan Kopp, MD and a group from San Diego, focused specifically on the subset of clinical T2 kidney cancer. They found that the benefits of performing a PN versus a RN disappear when patients have a R.E.N.A.L. score higher than 10. On top of that, they found that, in those patients, PN carries a high risk of bleeding and urine leak. The extensive resection, manipulation, and reconstruction related to treating larger masses exacerbates these risks.

Take-Home Message

Overall, it is important to analyze risk/benefit trade-offs when deciding to use either PN or RN, taking patient characteristics, age, comorbidities, baseline kidney function, tumor complexity (not simply tumor size), and the clinician’s surgical expertise into account. Also, clinicians should preoperatively counsel the patient to determine the best choice for that individual.

PN, or nephron sparing surgery, does not translate into clear benefit for any patient. But, it may represent a preferable option for patients with larger tumors in very selective cases. However, radical nephrectomy remains the standard.