How do treatments for renal cell carcinoma differ in their effect on kidney function?

Stereotactic body radiotherapy (SBRT) may provide the best combination of preserved renal function and low toxicity compared with radical nephrectomy, partial nephrectomy, and ablative therapies (including microwave, cryo, thermal, and radiofrequency) in the treatment of patients with localized renal cell carcinoma (RCC), according to data from a recent meta-analysis.¹

Nicholas Zaorsky, MD, MS

The findings were presented by Nicholas Zaorsky, MD, MS, at the 2024 American Society for Radiation Oncology Annual Meeting in Washington, DC. Zaorsky is vice chair of education and associate professor in the Department of Radiation Oncology, University Hospitals Seidman Cancer Center, Case Western Reserve School of Medicine, in Cleveland, Ohio.

Overall, the analysis included data from 42 studies published from 2013 to 2023. Of those, 17 studies evaluated partial nephrectomy, 12 evaluated ablative therapies, 11 evaluated SBRT, and 5 evaluated radical nephrectomy. The median follow-up between all studies was 47 months.

Data showed that the mean difference in pre- vs post-treatment estimated glomerular filtration rate (eGFR) was highest among patients who underwent radical nephrectomy. Specifically, the difference was 21.8 (95% CI, 17.2-26.3) for radical nephrectomy, 8.6 (95% CI, 2.9-14.3) for SBRT, 5.5 (95% CI, 3.1-7.9) for partial nephrectomy, and 5.1 (95% CI, 2.2-8.0) for ablative therapies.

There was a statistically significant difference in eGFR decline for radical nephrectomy vs all other treatment modalities (P < .0001) based on meta-regression. No statistically significant difference in eGFR was seen between ablative therapies, partial nephrectomy, and SBRT.

However, regarding safety, SBRT was associated with significantly fewer grade 3-5 toxicity events vs other treatment modalities. Specifically, SBRT was associated with 0.2 events per 100 treatments (95% CI, 0-1.1) compared with 4.7 events with partial nephrectomy (95% CI, 3.6-6.0; P = .003) and 4.3 with ablative therapies (95% CI, 3.3-5.4; P = .0057).

In total, the study assessed data from 7810 patients with T1-3N0M0 RCC who underwent definitive local therapy with either SBRT, radical nephrectomy, partial nephrectomy, or an ablative therapy (including microwave, cryo, thermal, and radiofrequency). The median age of patients was 65 years, and the median tumor size was 3.4 cm.

The primary end point for the study was pre- and post-treatment eGFR. The secondary outcome measure was grade 3-5 toxicity events.

Based on these findings, Zaorsky concluded in an interview with Urology Times, “This, in combination with the results of trials that have been presented and published within the past few years from the IROC consortium—where we see that the cancer control rate is above 95% or close to 100%—we think that radiation therapy is one of the best treatment options available for kidney cancer. And so, we hope that this study can help guide discussions among physicians and patients, in terms of selecting the best treatment option, and it can also help to guide a randomized, controlled trial—and powering the trial appropriately—so that we can get some prospective data to compare the different treatments.”

Reference

1. Rajoulh C, Ali M, Wang M, et al. Renal function after definitive local therapy for primary renal cell carcinoma: A meta-analysis. Presented at: American Society for Radiation Oncology Annual Meeting. September 29-October 2, 2024. Washington, DC. Abstract 219. https://www.redjournal.org/article/S0360-3016(24)00888-5/fulltext