New Paradigms for Cytoreductive Nephrectomy: Comparison
Please note this is a comparison between Version 2 by Jason Zhu and Version 1 by Benjamin Jared Lichtbroun.

Cytoreductive surgery (CS) is performed to remove the primary tumor in the setting of metastatic disease. In metastatic renal cell carcinoma (mRCC), the role of cytoreductive nephrectomy (CN) in the treatment paradigm has evolved, adjusting to new changes in systemic therapy agents. In particular, immunotherapeutic agents, which utilize the body’s own immune system to attack cancerous cells, have improved over the past decade. Newer immunotherapy agents offer more effective treatments in mRCC, with the goal of more tolerable side effect profiles.

  • cytoreductive nephrectomy
  • immune-oncologic agents
  • metastatic renal cell carcinoma

1. The Cytokine Period

During the cytokine era in the early 2000s, the SWOG group performed a prospective, randomized trial to assess whether a nephrectomy offered a survival benefit in patients with mRCC. Patients with mRCC were offered a nephrectomy followed by interferon alpha-2b compared with others who received interferon alpha-2b alone. In tThis study, there was a median survival benefit of 11.1 months vs. 8.1 months (p = 0.05) in the group that received surgery [10][1]. During that time, the EORTC group also published a similar study looking at nephrectomy plus interferon therapy compared with interferon therapy alone in patients with mRCC. In their study, they found a PFS benefit of 5 months vs. 3 months in the surgery group (HR 0.6, 95% CI 0.36–0.97, p = 0.04) and an OS benefit of 17 months vs. 7 months in the surgery group (HR 0.54, 95% CI 0.31–0.94, p = 0.03) [11][2]. Given the similarities in these prospective randomized trials, the groups later published a combined analysis of their data. When assessed in this way, using an intention-to-treat analysis, the overall median survival was 13.6 months in the CN group and 7.8 months in the interferon-alone group (HR 0.69, 95% CI 0.55–0.87, p = 0.002). There was a 31% decrease in risk of death in the nephrectomy group. There was a 51.9% 1-year survival rate with the nephrectomy group compared to 37.1% in the interferon-alone group. The combined analysis provided a more accurate assessment of the treatment difference associated with CN. For instance, in the SWOG study alone, when controlling for performance status, there was no significant survival difference. With this combined analysis, there was now a significant survival difference when controlling for performance status.

2. Targeted Therapies

In the years following the publication of these aforementioned landmark studies, there were improvements in ourthe understanding of the molecular basis of RCC. At that time, there was a transition to the use of targeted therapies such as VEGF inhibitors, mTOR inhibitors, and tyrosine kinase inhibitors (TKIs). In 2010, Choueiri et al. performed a retrospective review looking at 314 patients with mRCC who either received VEGF targeted therapy alone or VEGF targeted therapy with CN [14][3]. The specific therapies used were sorafenib, sunitinib, or bevacizumab. In tThis study, there was a median OS benefit of 19.8 months vs. 9.4 months in the surgery group compared to the VEGF-alone group (HR 0.44, 95% CI 0.32–0.59, p < 0.01) [14][3]. The National Cancer Database was then used in order to assess the survival benefit of CN in patients treated with targeted therapy. In the 15,390 patients treated with targeted therapy at that time, 5374 (35%) underwent CN between 2006–2013. The OS was 17.1 months vs. 7.7 months in the cytoreductive nephrectomy group compared to targeted therapy alone (p < 0.001). There were multiple patient factors and socioeconomic factors associated with receiving a CN, including being younger, being treated at an academic center, being privately insured, having a lower tumor stage, and having N0 [15][4]. A meta-analysis was also performed at that time looking at the role of CNs in patients treated with targeted therapies, which also showed an overall survival benefit with CN (HR 0.46, 95% CI 0.32–0.64, p < 0.01) [16][5].
Up until 2017, there were numerous studies supporting nephrectomies performed in the cytoreductive setting. In 2018, the results of the CARMENA trial called into question the utility of CN in the targeted therapy era. The CARMENA trial was a prospective, randomized, phase III trial. It was a non-inferiority design that compared sunitinib alone vs. sunitinib after CN in patients with mRCC. IOn this study, only intermediate-risk and poor-risk patients were included. With regard to OS, the sunitinib-alone group was found to be non-inferior to the CN group—18.4 months vs. 13.9 months (HR 0.89, 95% CI 0.71–1.10). One critique was that the study was underpowered as they were only able to accrue 450 of a planned 576 subjects. The study was also slow to accrue, in that it took 8 years to accrue the necessary patients across 79 centers. This accounts for 0.7 subjects per center per year, which points out that the study sites were either low-volume centers or there was a lack of equipoise, and not all providers recommended trial participation to all potential participants. Patient selection was also a major issue in that the study had mostly poor-risk patients with a high burden of disease. Furthermore, 57% of these patients had high-risk disease according to the MSKCC/Motzer score. In addition, 72% of the patients in this trial had non-lung metastasis with a median tumor burden of 14.2 cm, making this population particularly high-risk. There was also significant cross-over between the two groups with 15% of the patients in the nephrectomy group not receiving sunitinib and 17% of the patients in the sunitinib-alone group undergoing a nephrectomy. In addition, the 18.4-month OS reported in the sunitinib group was lower than other previously published reports, again raising questions about patient selection and generalizability. While the sunitinib-alone arm did show non-inferiority, the previously mentioned critiques largely limited its broad applicability [17][6].
Shortly after the publication of the CARMENA trial, the results of the SURTIME trial were published. In this trial, the reseauthorchers compared immediate vs. deferred CN in patients with mRCC receiving sunitinib therapy [18][7]. Initially, the primary end point of the study was set to be PFS with an initial sample size of 458 patients. Due to low accrual at 3 years, the independent data monitoring committee endorsed reporting a 28-week progression-free rate and decreased the sample size to 98 patients. OS, adverse events, and post-operative progression were secondary end points. The 28-week progression-free rate was 42% in the immediate CN and 43% in the deferred CN arm.
Much like the CARMENA trial, thise study also had certain significant limitations. For one, there was low accrual. In addition, the primary end point with 28-week progression-free survival required complex timing in order to appropriately ascertain these data. Notably, the superiority of the combination of nivoulumab and ipilimumab over sunitinib, in terms of survival and quality of life, changed the first-line therapy for patients with intermediate and poor-risk mRCC, limiting the applicability of the results of the SURTIME and CARMENA trials [18][7]. The reseauthorchers of the CARMENA trial did later perform a post-hoc analysis of overall survival in patients who had a secondary nephrectomy. A total of 40 patients (18%) in the sunitinib-alone group ultimately underwent secondary CN. Of those, 31% resumed sunitinib therapy after surgery.
The SURTIME group did later assess their data with regard to surgical safety. When comparing the immediate and deferred CN groups, the rates of all adverse events were essentially the same—52% vs. 53%, respectively [20][8]. These data show that while CN is of course a morbid procedure, the use of TKIs in either setting did not increase the rates of adverse events [20][8]. Following this publication, an analysis on the Registry for Metastatic Renal Cell Carcinoma registry was performed in order to measure the rates and predictors of perioperative complications [21][9]. Data from 736 mRCC patients undergoing CN at 14 institutions were retrospectively studied. Logistical regression analysis was used in order to identify predictors of intraoperative complications, post-operative complications, as well as 30-day readmission rates. Intraoperative complications were seen in 10.9% of patients. Interestingly, 29.5% of patients encountered a post-operative complication of any grade, with 6.1% encountering high grade complications. The 30-day readmission rate was 11.5% overall.

3. Optimizing Patient Selection

In patients undergoing CN, Akimi et al. aimed to determine the association between certain modifiable International Metastatic Renal Cell Carcinoma Database Consortium (IMDC) risk factors and oncologic outcomes. Furthermore, 245 patients were treated at a single institution between 2009 and 2019 [22][10]. The primary variable of interest was the type and number of IMDC risk factors such as anemia, hypercalcemia, neutrophilia, thrombocytosis, and reduced Karnofsky performance status at the time of initial clinical evaluation. The final IMDC risk factor, “less than 1 year from diagnosis to systemic therapy”, was not assessed in the treatment-naïve cohort as it was calculated at the time of commencing therapy. In the patients who underwent CN, IMDC-modifiable risk factors were assessed at 6 weeks and 6 months after surgery with the Karnofsky performance status calculated each time. Radiographic imaging was used to assess disease burden each time. Sites were grouped broadly into viscera, bones, nodes, or other sites. They were also grouped as either unifocal (one organ) or multifocal (multiple organs). In all time points—pre-operatively, 6 weeks post-op, and 6 months post-op—higher numbers of IMDC risk factors were all associated with adverse overall survival (HR 1.41, 95% CI 1.19–1.68, p < 0.001; HR 1.55, 95% CI 1.25–1.92, p < 0.001; HR 2.43, 95% CI 1.85–3.21, p < 0.001). In patients who had a decrease in IMDC risk factors at 6 weeks, they were shown to have improved overall survival (HR 0.64, 95% CI 0.46–0.89, p = 0.007). When assessing only high-risk patients with 2 or more IMDC risk factors, patients who were able to reduce the number of IMDC risk factors to one or fewer saw an increase in overall survival at 6 weeks (p = 0.36) and 6 months (p < 0.001) [22][10]. A recent retrospective multicenter study aimed to evaluate the survival benefit of upfront CN in mRCC, stratified by IMDC risk factors. Charts were reviewed for patients who received upfront CN, deferred CN, and systemic therapy alone over an 11-year span. Of the 259 patients who met the inclusion criteria, 107 were classified as being in the upfront CN group. After inverse probability of treatment weighting, upfront CN was found to have a survival benefit in patients with IMDC intermediate- and poor-risk disease [23][11].

4. Immune Checkpoint Inhibitors—What We Know

Immune checkpoint inhibitors have ushered in a contemporary era of immunotherapy in mRCC. First with the CheckMate 025 trial and subsequently with the CheckMate 214, KEYNOTE-426, CLEAR, IMmotion151, and JAVELIN Renal 101 trials, immunotherapies have become a staple in the management of mRCC. In the metastatic setting, immune checkpoint inhibitor combination therapies have led to primary tumor shrinkage [25][12]. With the advent of immune checkpoint inhibitors, the role for cytoreductive surgery remains unknown. A recent NCDB study reviewed 391 surgical candidates diagnosed with metastatic clear cell RCC. Patients were treated with either contemporary immunotherapy alone or combined with CN. No other systemic therapies were used in this cohort. Patients who underwent CN and received immunotherapy had a significantly better OS than those who received immunotherapy alone (HR 0.23, 95% CI 0.15–0.37, p < 0.001) [26][13].
To highlight the superiority of newer immune checkpoint inhibitors over the previous first-line therapy, sunitinib, in advanced renal cell carcinoma, a recent Phase 3, open-label, randomized trial compared sunitinib alone against nivolumab with cabozantinib. TIt his studyas been found that in the non-cytoreductive setting, the combination of nivolumab and cabozantinib offered an increase in overall survival, progression-free survival, and likelihood of response [27][14].

5. Immune Checkpoint Inhibitors—Ongoing Trials

In the contemporary immunotherapy era, the role of CN has yet to be clearly elucidated by publications with high levels of evidence. Currently, there are multiple trials looking at this exact clinical question [9][15]. With the superiority of nivolumab and cabozantinib over sunitinib in the advanced renal cell carcinoma population, researchers are aiming to determine the complete response rate in patients receiving neoadjuvant nivolumab and cabozantinib followed by nephrectomy and subsequent systemic therapy in the Cyto-KIK trial [28][16]. Within thprevious studyies, patients will also have renal mass biopsies prior to beginning treatment in order to determine biomarkers of response in this population through analysis of RNA sequencing. Comparing these samples to the nephrectomy specimens may help to clarify the mechanism of action in responding patients and the mechanism of resistance in non-responders [28][16].

Other ongoing studies, including the NORDIC-SUN and PROBE trials, are comparing patients who are receiving immune checkpoint inhibitors alone or in combination compared to patients receiving those medications in addition to cytoreductive surgery [28]. In the PROBE trial, researchers are evaluating if CN offers a survival benefit in patients who had an objective response or stable disease at metastatic sites after receiving any of the multiple first-line options for systemic therapy. This study includes patients with histologically proven clear cell RCC or non-clear cell RCC. Patients will be evaluated after 12 weeks of systemic immune checkpoint inhibition to assess their response to treatment and whether there is benefit in performing a CN.

The NORDIC SUN trial is evaluating the role of deferred CN in patients who have at least three IMDC high-risk features and are receiving combination nivolumab and ipilimumab [25]. The rationale behind the deferred CN is that it still provides the benefit of surgery while not delaying systemic immune checkpoint inhibition. It also spares surgery in patients with progressive tumors. The primary end point in both the NORDIC SUN and PROBE trials is OS.

References

  1. Flanigan, R.C.; Salmon, S.E.; Blumenstein, B.A.; Bearman, S.I.; Roy, V.; McGrath, P.C.; Caton, J.R.; Munshi, N.; Crawford, E.D. Nephrectomy Followed by Interferon Alfa-2b Compared with Interferon Alfa-2b Alone for Metastatic Renal-Cell Cancer. N. Engl. J. Med. 2001, 345, 1655–1659.
  2. Mickisch, G.H.J.; Garin, A.; Van Poppel, H.; de Prijck, L.; Sylvester, R. Radical nephrectomy plus interferon-alfa-based immunotherapy compared with interferon alfa alone in metastatic renal-cell carcinoma: A randomised trial. Lancet 2001, 358, 966–970.
  3. Choueiri, T.K.; Xie, W.; Kollmannsberger, C.; North, S.; Knox, J.J.; Lampard, J.G.; McDermott, D.F.; Rini, B.I.; Heng, D.Y.C. The impact of cytoreductive nephrectomy on survival of patients with metastatic renal cell carcinoma receiving vascular endothelial growth factor targeted therapy. J. Urol. 2011, 185, 60–66.
  4. Hanna, N.; Sun, M.; Meyer, C.P.; Nguyen, P.L.; Pal, S.K.; Chang, S.L.; de Velasco, G.; Trinh, Q.-D.; Choueiri, T.K. Survival analyses of patients with metastatic renal cancer treated with targeted therapy with or without cytoreductive nephrectomy: A National Cancer Data Base study. J. Clin. Oncol. 2016, 34, 3267.
  5. Petrelli, F.; Coinu, A.; Vavassori, I.; Cabiddu, M.; Borgonovo, K.; Ghilardi, M.; Lonati, V.; Barni, S. Cytoreductive nephrectomy in metastatic renal cell carcinoma treated with targeted therapies: A systematic review with a meta-analysis. Clin. Genitourin. Cancer 2016, 14, 465–472.
  6. Méjean, A.; Ravaud, A.; Thezenas, S.; Colas, S.; Beauval, J.-B.; Bensalah, K.; Geoffrois, L.; Thiery-Vuillemin, A.; Cormier, L.; Lang, H.; et al. Sunitinib Alone or after Nephrectomy in Metastatic Renal-Cell Carcinoma. New Engl. J. Med. 2018, 379, 417–427.
  7. Bex, A.; Mulders, P.; Jewett, M.; Wagstaff, J.; van Thienen, J.V.; Blank, C.U.; van Velthoven, R.; Laguna, M.D.P.; Wood, L.; van Melick, H.H.E.; et al. Comparison of Immediate vs Deferred Cytoreductive Nephrectomy in Patients with Synchronous Metastatic Renal Cell Carcinoma Receiving Sunitinib: The SURTIME Randomized Clinical Trial. JAMA Oncol. 2019, 5, 164–170.
  8. De Bruijn, R.E.; Mulders, P.; Jewett, M.A.; Wagstaff, J.; Van Thienen, J.V.; Blank, C.U.; Velthoven, R.V.; Wood, L.; van Melick, H.E.; Aarts, M.J.; et al. Surgical safety of cytoreductive nephrectomy following sunitinib: Results from the multicentre, randomised controlled trial of immediate versus deferred nephrectomy (SURTIME). Eur. Urol. 2019, 76, 437–440.
  9. Roussel, E.; Campi, R.; Larcher, A.; Verbiest, A.; Antonelli, A.; Palumbo, C.; Derweesh, I.; Ghali, F.; Bradshaw, A.; Meagher, M.F.; et al. Rates and Predictors of Perioperative Complications in Cytoreductive Nephrectomy: Analysis of the Registry for Metastatic Renal Cell Carcinoma. Eur. Urol. Oncol. 2020, 3, 523–529.
  10. Silagy, A.W.; Kotecha, R.R.; Weng, S.; Holmes, A.; Singla, N.; Mano, R.; Attalla, K.; Weiss, K.L.; DiNatale, R.G.; Patil, S.; et al. Evolving biological associations of upfront cytoreductive nephrectomy in metastatic renal cell carcinoma. Cancer 2021, 127, 3946–3956.
  11. Kato, R.; Naito, S.; Numakura, K.; Hatakeyama, S.; Koguchi, T.; Kojima, T.; Kawasaki, Y.; Kandori, S.; Kawamura, S.; Arai, Y.; et al. Significance of upfront cytoreductive nephrectomy stratified by IMDC risk for metastatic renal cell carcinoma in targeted therapy era—A multi-institutional retrospective study. Int. J. Clin. Oncol. 2022, 27, 563–573.
  12. Méjean, A.; Bex, A. Cytoreductive Nephrectomy: Still Necessary in 2021. Eur. Urol. Open Sci. 2022, 36, 49–50.
  13. Singla, N.; Hutchinson, R.C.; Ghandour, R.A.; Freifeld, Y.; Fang, D.; Sagalowsky, A.I.; Lotan, Y.; Bagrodia, A.; Margulis, V.; Hammers, H.J.; et al. Improved survival after cytoreductive nephrectomy for metastatic renal cell carcinoma in the contemporary immunotherapy era: An analysis of the National Cancer Database. Urol. Oncol. Semin. Orig. Investig. 2020, 38, 604.e9–604.e17.
  14. Choueiri, T.K.; Powles, T.; Burotto, M.; Escudier, B.; Bourlon, M.T.; Zurawski, B.; Juárez, V.M.O.; Hsieh, J.J.; Basso, U.; Shah, A.Y.; et al. Nivolumab plus cabozantinib versus sunitinib for advanced renal-cell carcinoma. N. Engl. J. Med. 2021, 384, 829–841.
  15. Schmidt, A.L.; Tabakin, A.L.; Singer, E.A.; Choueiri, T.K.; McKay, R.R. Next Steps: Sequencing Therapies in Metastatic Kidney Cancer in the Contemporary Era. Am. Soc. Clin. Oncol. Educ. Book 2021, 41, 1–11.
  16. Tabakin, A.L.; Stein, M.N.; Anderson, C.B.; Drake, C.G.; Singer, E.A. Cytoreductive nephrectomy for metastatic renal cell carcinoma, the ultimate urologic ’Choosing Wisely’ campaign: A narrative review. Transl. Cancer Res. 2020, 9, 7337–7349.
More
ScholarVision Creations