Djaladat, Hooman

454 Background: Immune checkpoint inhibitor (ICI)-based combination therapy has become the standard of care for advanced renal cell carcinoma (RCC). A pathologic complete response (pCR) in the primary tumor may be observed in up to one-third of patients; however, data on the outcomes of these patients remain limited. This study aimed to evaluate the clinical outcomes of patients who achieved a pCR following ICI therapy. Methods: Patients with advanced RCC who underwent nephrectomy following ICI therapy were evaluated across five high-volume U.S. academic centers between 2015 and 2023. Clinical characteristics and outcomes were compared between those with and without a pCR in the primary tumor (ypT0N0/Nx). Multivariable logistic regression models were used to identify factors associated with pCR. Recurrence-free (RFS) and overall survival (OS) rates were estimated using the Kaplan-Meier (KM) method. Results: A total of 182 patients were included (Table 1). Among all patients, downstaging to ≤ypT1N0/Nx was observed in 45 patients (25%), of whom 21 (11%) achieved a pCR. In multivariable analysis, the presence of clinical thrombus was marginally associated with a lower likelihood of achieving pCR (odds ratio [95% CI]: 0.39 [0.15–1.00], p=0.06). During a median follow-up of 25 months, 70 patients (38%) experienced recurrence, including 4 (2%) in the pCR group. Median time to recurrence was 7.5 months. KM analysis demonstrated a higher estimated 5-year RFS in the pCR group compared to those with residual disease; however, the difference was not statistically significant (68% vs. 54%, p=0.2). In addition, OS rates were comparable between the two groups. Conclusions: In our cohort, 11% of patients who underwent nephrectomy following ICI therapy for advanced RCC showed pCR, which correlated with improved oncologic outcomes. Despite the lower recurrence rates observed in the pCR group, sustained long-term surveillance remains necessary due to the continued, albeit reduced, risk of disease recurrence. Clinical characteristics of patients who underwent post-ICI nephrectomy, stratified by their pathologic complete response (pCR). Variable pCR (n=21) No pCR (n=161) p-value Median (IQR) age, year 61 (56 – 70) 64 (56 – 71) 0.46 Gender (male), n (%) 15 (71) 118 (73) 0.8 Tumor advancement, n (%) Locally advanced Metastatic 2 (10)19 (90) 36 (22)125 (78) 0.26 Risk group (for metastatic), n (%) Favorable Intermediate Poor 3 (25)6 (50)3 (25) 38 (34)59 (54)13 (12) 0.42 ICI regimen, n (%) ICI monotherapy ICI+ICI ICI+TKI 4 (19)9 (43)8 (38) 46 (28)64 (40)51 (32) 0.64 Immunotherapy cycles (>4), n (%) 8 (50) 49 (37) 0.42 Median (IQR) clinical tumor size, cm 9.3 (6.7 – 11.9) 8.4 (6.6 – 12) 0.68 Clinical nodal involvement, n (%) 8 (38) 53 (33) 0.63 Clinical thrombus, n (%) 12 (57) 60 (37) 0.1 ICI: immune checkpoint inhibitor; TKI: tyrosine kinase inhibitor.

Objectives To develop an internationally validated, structured robot‐assisted radical nephroureterectomy (RARNU) training programme through expert consensus. Materials and Methods A RARNU‐specific questionnaire was developed/adapted from previously published, validated questionnaires for robot‐assisted urological procedures. This included five key domains and 11 surgical steps. In all, 30 upper tract urothelial carcinoma experts were invited to participate. A two‐stage modified Delphi approach was employed. Consensus was defined as ≥80% agreement. Modifications and additional statements were proposed during the second round following qualitative/quantitative feedback from the initial round. Results Response rates for the first and second Delphi rounds were 80% (24/30) and 92% (22/24), respectively. All agreed that adoption of a standardised training curriculum can improve clinical outcomes during the RARNU learning curve. There was ≥92% agreement on all proposed RARNU steps. Five RARNU clinical modules of increasing complexity were defined using individual step difficulty and number of prior RARNU cases required, with ≥96% agreement among respondents. Respondents unanimously agreed that the final assessment should be based on a procedure‐specific scale focusing on the hilar dissection, ureteric dissection, and bladder cuff excision steps. No consensus was reached for the annual minimum RARNU volume required for eligibility as a RARNU curriculum host centre. Conclusion This is the first structured training curriculum for RARNU using international expert consensus. This will help guide surgical educators and trainees toward independent completion of a full RARNU.

Objectives: To report the outcomes of minimally invasive (MIS) nephrectomy following immune checkpoint inhibitor (ICI) therapy. Materials and Methods: This multicenter retrospective cohort study included consecutive patients who underwent nephrectomy following ICI therapy at five high-volume US academic centers between 2015 and 2023. Baseline clinical features and perioperative findings were recorded. After propensity-score matching (PSM), outcomes were compared between MIS and open nephrectomies. The primary outcome was 90-day complications, and secondary outcomes included length of hospital stay (LOS) and 90-day readmission. Results: A total of 158 patients were included, of whom 76 and 82 underwent MIS and open nephrectomies, respectively. The MIS procedures included robotic ( n = 56) and laparoscopic ( n = 20). A total of six (8%) patients converted to open. On multivariable analysis, patients with nonmetastatic vs metastatic renal-cell carcinoma (RCC) (hazard ratio [HR] 3.1, p = 0.01), those with smaller tumor size (HR 1.2 for each cm, p = 0.001), and no clinical evidence of inferior vena cava thrombus (HR 29, p = 0.002) were more likely to undergo the MIS approach compared with open approach. After PSM, including 56 MIS and 36 open nephrectomies, the MIS group compared with the open group had lower estimated blood loss (100 vs 460 mL, p < 0.001) and shorter LOS (2 vs 4 days, p < 0.001). Nevertheless, 90-day complications and readmissions were similar between the two groups. There were no 90-day mortality rates in either group. Conclusion: The MIS approach appears safe and offers more favorable perioperative outcomes compared with open surgery in properly selected patients with advanced RCC who are candidates for nephrectomy following ICI therapy.

Objectives To reassess the role of primary retroperitoneal lymph node dissection (RPLND) in patients with marker‐negative non‐seminomatous germ cell tumour (NSGCT) clinical stage (CS) 2a, to explore results in patients with CS 2b and to evaluate surgical methods, recurrence, and adjuvant chemotherapy indications. Materials and Methods Data from 17 institutions were collected, comprising 305 men who underwent primary RPLND for CS 2 NSGCT. Regression analyses were conducted to predict histology in the RPLND specimen and disease‐free survival (DFS). Results A larger retroperitoneal lymph node diameter was associated with pure teratoma in the RPLND specimen (odds ratio [OR] 1.02, 95% confidence interval [CI] 1.01–1.07; P = 0.03), but no association was observed with DFS. The 5‐year DFS rates in marker negative CS 2a and 2b were 79% and 76%. In men with non‐teratomatous viable cancer in the RPLND specimen, the 5‐year DFS rates for CS 2a and 2b were 95% and 87% with adjuvant chemotherapy, and 67% and 74% without adjuvant chemotherapy. We did not identify an association between the number of adjuvant chemotherapy cycles and DFS. Conclusions Our study suggests considering primary RPLND not only in marker‐negative CS 2a but also in CS 2b. Further research should determine the efficacy of primary RPLND in men with CS 2c and marker‐positive CS 2, as well as which patients may benefit from adjuvant chemotherapy and the optimal cycle number.

Background: Although previous literature shows tumor location as a prognostic factor in upper tract urothelial carcinoma (UTUC), there remains uninvestigated regarding the impact of tumor location on grade concordance and discrepancies between ureteroscopic (URS) biopsy and final radical nephroureterectomy (RNU) pathology. Methods: In this international study, we retrospectively reviewed the records of 1,498 patients with UTUC who underwent diagnostic URS with concomitant biopsy followed by RNU between 2005 and 2020. Tumor location was divided into four sections: the calyceal-pelvic system, proximal ureter, middle ureter, and distal ureter. Patients with multifocal tumors were excluded from the study. We performed multiple comparison tests and logistic regression analyses. Results: Overall, 1,154 patients were included; 54.4% of those with low-grade URS biopsies were upgraded on RNU. In the multiple comparison tests, middle ureter tumors exhibited the highest probability of upgrading, meanwhile pelvicalyceal tumors exhibited the lowest probability of upgrading (73.7% vs 48.5%, p = 0.007). Downgrading was comparable across all tumor locations. On multivariate analyses, middle ureteral location was significantly associated with a low probability of grade concordance (odds ratio [OR] 0.59; 95% confidence interval [CI], 0.35–1.00; p = 0.049) and an increased risk of upgrading (OR 2.80; 95% CI, 1.20–6.52; p = 0.017). The discordance did not vary regardless of caliceal location, including the lower calyx. Conclusions: Middle ureteral tumors diagnosed to be low grade had a high probability to be undergraded. Our data can inform providers and their patients regarding the likelihood of undergrading according to tumor location, facilitating patient counseling and shared decision making regarding the choice of kidney sparing vs RNU.

516 Background: Based on only smaller retrospective cohort studies, current guidelines recommend primary retroperitoneal lymph node dissection (RPLND) for men with marker-negative stage 2a non-seminomatous germ cell tumor (NSGCT). We aimed to reassess the role of primary RPLND in marker negative stage 2a, explore results in stages 2b/c and/or marker-positive disease, and evaluate surgical methods, recurrence, and adjuvant chemotherapy indications. Methods: Data from 17 institutions were collected, comprising 305 men who underwent primary RPLND for stage 2 NSGCT. Regression analyses were conducted to predict histology in the RPLND specimen and progression-free survival (PFS). Results: A larger retroperitoneal lymph node diameter was associated with pure teratoma in the RPLND specimen (odds ratio [OR] 1.03, 95% confidence interval [CI] 1.01-1.09, p-value = 0.02), but it did not correlate with PFS. The 5-year PFS rates were 85% for men with pure teratoma, 94% for men with viable cancer who received adjuvant chemotherapy, and 72% for men with viable cancer who did not receive adjuvant chemotherapy. The number of adjuvant chemotherapy cycles did not significantly affect PFS. Conclusions: Our study suggests considering primary RPLND not only in marker negative clinical stage 2a but also marker negative clinical stage 2b. Further research should identify the efficacy in men in other stages (2C or marker positive) and which patients may benefit from adjuvant chemotherapy and the optimal cycle number.

475 Background: Emerging evidence supports use of neoadjuvant chemotherapy (NAC) prior to radical nephroureterectomy (RNU) for appropriately selected patients with upper tract urothelial carcinoma (UTUC). However, oncologic outcomes have not been well characterized for patients with residual muscle-invasive disease after NAC. Methods: We used a multi-institutional cohort from 24 centers in the U.S., Europe, and Japan to retrospectively identify patients who underwent RNU for UTUC from 1985-2022 and had high-grade muscle-invasive disease. We stratified the cohort based on receipt of NAC (>ypT2 vs. >pT2). Exclusion criteria included receipt of adjuvant chemotherapy, concurrent cystectomy with RNU, and distant metastatic disease. Baseline characteristics were compared between groups. Kaplan-Meier survival analysis with log-rank test was used to compare differences in recurrence-free survival (RFS), overall survival (OS), and cancer-specific survival (CSS). Multivariable Cox regression and Fine-Gray competing risk regression were used to determine predictors of these outcomes. Results: A total of 1,233 patients were included, 62 of whom received NAC prior to RNU. A platinum-based regimen was used in 90% of NAC recipients, and the median number of cycles administered was 4 (IQR: 3-5). Median follow-up time among all patients was 22 months (IQR: 8-47 mo.). NAC recipients were more likely to have pathologic node positivity (35% vs. 13%) and less likely to have positive tumor margins (8% vs. 28%). On Kaplan-Meier analysis, NAC recipients with residual >ypT2 disease had poorer outcomes than those with >pT2 disease (2-year RFS [NAC vs. no NAC]: 52% vs. 80%, p<0.001; 2-year OS: 60% vs. 78%, p=0.003; 2-year CSS: 61% vs. 86%, p<0.001). Multivariable analyses also showed a statistically significant association between residual muscle-invasive disease after NAC and poorer RFS, OS, and CSS (Table). Conclusions: NAC recipients with >ypT2 disease at RNU after exhibit poorer outcomes than stage-matched chemotherapy naïve counterparts. This may reflect effects of occult micrometastatic disease or chemoresistant primary tumors in non-responders. Our data highlight the need to improve prospective identification of candidates most likely to respond to NAC prior to RNU for UTUC in order to maximize its therapeutic benefit. [Table: see text]

Objectives: To identify correlates of survival and perioperative outcomes of upper tract urothelial carcinoma (UTUC) patients undergoing open (ORNU), laparoscopic (LRNU), and robotic (RRNU) radical nephroureterectomy (RNU). Methods: We conducted a retrospective, multicenter study that included non-metastatic UTUC patients who underwent RNU between 1990–2020. Multiple imputation by chained equations was used to impute missing data. Patients were divided into three groups based on their surgical treatment and were adjusted by 1:1:1 propensity score matching (PSM). Survival outcomes per group were estimated for recurrence-free survival (RFS), bladder recurrence-free survival (BRFS), cancer-specific survival (CSS), and overall survival (OS). Perioperative outcomes: Intraoperative blood loss, hospital length of stay (LOS), and overall (OPC) and major postoperative complications (MPCs; defined as Clavien–Dindo > 3) were assessed between groups. Results: Of the 2434 patients included, 756 remained after PSM with 252 in each group. The three groups had similar baseline clinicopathological characteristics. The median follow-up was 32 months. Kaplan–Meier and log-rank tests demonstrated similar RFS, CSS, and OS between groups. BRFS was found to be superior with ORNU. Using multivariable regression analyses, LRNU and RRNU were independently associated with worse BRFS (HR 1.66, 95% CI 1.22–2.28, p = 0.001 and HR 1.73, 95%CI 1.22–2.47, p = 0.002, respectively). LRNU and RRNU were associated with a significantly shorter LOS (beta −1.1, 95% CI −2.2–0.02, p = 0.047 and beta −6.1, 95% CI −7.2–5.0, p < 0.001, respectively) and fewer MPCs (OR 0.5, 95% CI 0.31–0.79, p = 0.003 and OR 0.27, 95% CI 0.16–0.46, p < 0.001, respectively). Conclusions: In this large international cohort, we demonstrated similar RFS, CSS, and OS among ORNU, LRNU, and RRNU. However, LRNU and RRNU were associated with significantly worse BRFS, but a shorter LOS and fewer MPCs.

ObjectivesTechnical limitations of ureteroscopic (URS) biopsy has been considered responsible for substantial upgrading rate in upper tract urothelial carcinoma (UTUC). However, the impact of tumor specific factors for upgrading remain uninvestigated.MethodsPatients who underwent URS biopsy were included between 2005 and 2020 at 13 institutions. We assessed the prognostic impact of upgrading (low‐grade on URS biopsy) versus same grade (high‐grade on URS biopsy) for high‐grade UTUC tumors on radical nephroureterectomy (RNU) specimens.ResultsThis study included 371 patients, of whom 112 (30%) and 259 (70%) were biopsy‐based low‐ and high‐grade tumors, respectively. Median follow‐up was 27.3 months. Patients with high‐grade biopsy were more likely to harbor unfavorable pathologic features, such as lymphovascular invasion (p < 0.001) and positive lymph nodes (LNs; p < 0.001). On multivariable analyses adjusting for the established risk factors, high‐grade biopsy was significantly associated with worse overall (hazard ratio [HR] 1.74; 95% confidence interval [CI], 1.10–2.75; p = 0.018), cancer‐specific (HR 1.94; 95% CI, 1.07–3.52; p = 0.03), and recurrence‐free survival (HR 1.80; 95% CI, 1.13–2.87; p = 0.013). In subgroup analyses of patients with pT2‐T4 and/or positive LN, its significant association retained. Furthermore, high‐grade biopsy in clinically non‐muscle invasive disease significantly predicted upstaging to final pathologically advanced disease (≥pT2) compared to low‐grade biopsy.ConclusionsHigh tumor grade on URS biopsy is associated with features of biologically and clinically aggressive UTUC tumors. URS low‐grade UTUC that becomes upgraded to high‐grade might carry a better prognosis than high‐grade UTUC on URS. Tumor specific factors are likely to be responsible for upgrading to high‐grade on RNU.