AUA 2023: Complete Pathological Response in Patients Undergoing Nephrectomy for RCC Following Immune Checkpoint Inhibitor Therapy: A Multicenter Study

(UroToday.com) The 2023 AUA annual meeting included an advanced kidney cancer session, featuring a presentation by Dr. Alireza Ghoreifi discussing complete pathological response in patients undergoing nephrectomy for renal cell carcinoma (RCC) following immune checkpoint inhibitor therapy. Immune checkpoint inhibitors are now among frontline treatments for advanced RCC, as highlighted by the following timeline:

 

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However, there is limited data available regarding the pathologic response in patients receiving immune checkpoint inhibitors and the outcomes of these cases:1

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This study aimed to evaluate predictors and outcomes of patients with complete pathologic response in the primary tumor following immune checkpoint inhibitor therapy.

 Patients with RCC undergoing nephrectomy following immune checkpoint inhibitor therapy were evaluated in three high-volume US academic centers between 2011 and 2022. Available pre-immune checkpoint inhibitors and preoperative computed tomography imaging were reviewed by expert radiologists. Radiological data, clinical features, and outcomes of patients with and without complete pathological response were compared.

 A total of 92 patients with a median age of 63 (IQR: 56-69) years were included. Among patients with available data, immune checkpoint inhibitor regimens (median cycles = 3) were nivolumab ± ipilimumab (n=76), and pembrolizumab ± axitinib (n = 12). Clinical, radiological, and pathological features of the patients are as follows:

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Among all patients, 90 (98%) underwent radical and 2 (2%) partial nephrectomy; 40 (43.5%) open, 40 (43.5%) robotic, and 12 (13%) a laparoscopic approach. Median operative time, estimated blood loss, and length of stay were 3 hours, 200 mL, and 3 days, respectively. Eight patients (9%) showed complete pathological response in the kidney. Complete pathological response was marginally associated with higher number of immune checkpoint inhibitor cycles (> 3 vs. ≤3 cycles: 16% vs. 4%, p=0.06), and with no other clinical or pretreatment radiologic variable. The 3-year overall and progression-free survivals in patients with complete pathological response was 100%; however, the same outcomes in other patients were 89% and 53%, respectively. As follows are the Kaplan-Meier curves demonstrating overall survival and progression free survival in patients with RCC undergoing nephrectomy post-immune checkpoint inhibitor therapy:

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Dr. Ghoreifi concluded his presentation by discussing complete pathological response in patients undergoing nephrectomy for RCC following immune checkpoint inhibitor therapy with the following take-home messages:

  • In this cohort, 9% of patients who underwent nephrectomy following immune checkpoint inhibitors for advanced RCC showed complete pathological response in nephrectomy specimen
  • These patients demonstrated more favorable overall and progression-free survivals compared to those with residual tumor in the final specimen

Presented by: Alireza Ghoreifi, MD, Research Fellow of Urologic Oncology, Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, CA

Written by: Zachary Klaassen, MD, MSc – Urologic Oncologist, Assistant Professor of Urology, Georgia Cancer Center, Augusta University/Medical College of Georgia, @zklaassen_md on Twitter during the 2023 American Urological Association (AUA) Annual Meeting, Chicago, IL, April 27 – May 1, 2023

References:

  1. Ghoreifi A, et al. JAMA Oncology 2023 [In Press].