Estimating Post-Nephrectomy GFR May Guide Treatment Decisions

Accurate estimation of future glomerular filtration rate (GFR) could help clinicians decide whether to perform partial or radical nephrectomy for challenging cases of renal cell carcinoma (RCC) or upper tract urothelial carcinoma (UTUC) and whether to use neoadjuvant or adjuvant therapies, according to a new editorial published in Nature Reviews Urology.

“Precision in the measurement of [future] GFR is increasingly needed owing to the potential influence of [future] GFR on decision-making about surgical as well as systemic treatment options for a large number of patients with RCC and UTUC,” Federico Ferraris, MD, of Sanatorio Otamendi in Buenos Aires, Argentina, and colleagues wrote.

The reviewers noted, for example, that a low predicted post-nephrectomy GFR might encourage the use of neoadjuvant therapies, which could downsize the tumor and permit partial nephrectomy.

The reviewers lauded a recent GFR equation that provides accurate estimation of post-nephrectomy GFR based on 5 key clinical points: estimated preoperative GFR; patient age; type of nephrectomy; tumor size; and presence of diabetes mellitus.

Diego Aguilar Palacios, MD, of the Glickman Urological and Kidney Institute, Cleveland Clinic Foundation in Ohio, and colleagues developed the equation using data from 7860 patients with RCC undergoing partial or radical nephrectomy at Veterans Affairs facilities. They analyzed 94,327 first-year postoperative GFR measurements and defined new baseline GFRs as the final GFR within 3 to 12 months after surgery. The simplest equation for new baseline GFR was: 35 + preoperative GFR (× 0.65) – 18 (if radical nephrectomy) – age (× 0.25) + 3 (if tumor size greater than 7 cm) – 2 (if diabetes). The investigators validated the equation using both an internal and external cohort.

“Our study provides a validated equation to accurately predict postoperative new baseline glomerular filtration rate in patients being considered for radical nephrectomy or partial nephrectomy that can be easily implemented in daily clinical practice,” Dr Palacios’ team concluded in The Journal of Urology.

The main limitation of the equation is the use of estimated preoperative GFR rather than measured GFR and may need to be refined.

In their editorial, Dr Ferraris and his coauthors commented, “This equation (or any similar equation with the same characteristics) should be included in future diagnosis and treatment guidelines to generate personalized recommendations for patients with RCC and UTUC about the type of surgery, as well as the potential use and timing of treatment with systemic adjuvant therapies.”

Disclosure: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.

References

Ferraris F, Raman JD, Musso CG, Rozanec J. Measuring renal function before kidney surgery – evolving towards precision in medicine. Nat Rev Urol. 2022 Aug;19(8):450-451. doi:10.1038/s41585-022-00613-1

Aguilar Palacios D, Wilson B, Ascha M, et al. New baseline renal function after radical or partial nephrectomy: A simple and accurate predictive model. J Urol. 2021 May;205(5):1310-1320. doi:10.1097/JU.0000000000001549

This article originally appeared on Renal and Urology News