Thompson, Robert Houston

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.

Objective To evaluate the association between renal tumour complexity and outcomes in a large cohort of patients undergoing percutaneous cryoablation ( PCA ). Patients and Methods Patients with renal tumours treated with PCA were identified using our prospectively maintained ablation registry (2003–2015). Salvage procedures and inherited tumour syndromes were excluded. The associations between R.E.N.A.L. nephrometry score ( NS ) and risk of complications, renal function impairment, local failure and cancer‐specific mortality ( CSM ) were evaluated using univariate and multivariable logistic, linear and Cox regression models. Results The cohort included 618 tumours treated during 580 procedures in 565 patients. The median (interquartile range [ IQR ]) follow‐up was 34 (14.66) months. Complications (any grade) during a procedure ( n [total] = 87, 15%) were more frequent with higher NS ( NS 4–6: 10%; NS 7–9: 14%; NS 10–12: 36%; P < 0.001). Higher NS was independently associated with risk of complications (odds ratio [ OR ; per 1 point] = 1.3; 95% confidence interval [ CI ] 1.2–1.5; P < 0.001). Of all the NS components, tumour size was the most strongly associated with complication risk ( OR 3.4; 95% CI 2.2–5.2; P < 0.001). The median ( IQR ) decline in glomerular filtration rate ( GFR ) from baseline was 9% (0, 22) at last follow‐up. Each additional point in NS was associated with a 1.3% (95% CI 0.4–2.1; P = 0.005) greater GFR decline from baseline. NS was not significantly associated with local failure ( n [total] = 14, 2%; NS 4–6: 2%; NS 7–9: 3%; NS 10–12: 5%; P = 0.32) or CSM ( n [total] = 8, 2%; NS 4–6: 2%; NS 7–9: 3%; NS 10–12: 2%; P = 0.88). Conclusion In high‐complexity tumours PCA was associated with a tumour size‐driven increased risk of post‐procedural complications. Higher NS was associated with a small, clinically minor additional decline in renal function. Risks for local failure and CSM were low, regardless of tumour complexity.

Objective To evaluate the incidence, predictors and oncological outcomes of pT 0 prostate cancer ( PC a). Methods We conducted a retrospective analysis of 20 222 patients undergoing radical prostatectomy ( RP ) for PC a at the Mayo Clinic between 1987 and 2012. Disease recurrence was defined as follow‐up PSA >0.4 ng/mL or biopsy‐proven local recurrence. Systemic progression was defined as development of metastatic disease on imaging. Comparisons of baseline characteristics between pT 0 and non‐ pT 0 groups were carried out using chi‐squared tests. Recurrence‐free survival was estimated using the Kaplan–Meier method and compared using the log‐rank test. Results A total of 62 patients (0.3%) had pT 0 disease according to the RP specimen. In univariable analysis, pT 0 disease was significantly associated with older age ( P = 0.045), lower prostate‐specific antigen ( PSA ; P = 0.002), lower clinical stage ( P < 0.001), lower biopsy Gleason score ( P = 0.042), and receipt of preoperative transurethral resection, hormonal and radiation therapies (all P < 0.001). In multivariable analysis, lower PSA levels, lower Gleason score, and receipt of preoperative treatment were independently associated with pT 0 (all P < 0.05). Seven patients (11%) with pT 0 PC a developed disease recurrence over a median follow‐up of 10.9 years. All seven patients had preoperative treatment(s) and three had recurrence with a PSA doubling time of <9 months. Compared with non‐ pT 0 disease, pT 0 disease was associated with longer recurrence‐free survival ( P < 0.05). Only one (1.6%) patient with pT 0 disease developed systemic progression. Conclusions pT 0 stage PC a is a rare phenomenon and is associated with receipt of preoperative treatment and features of low‐risk PC a. Although pT 0 has a very favourable prognosis, some men, especially those who received preoperative treatment, experience a small but non‐negligible risk of disease recurrence and systemic progression.

Objective To evaluate the outcome of patients after surgical resection of isolated retroperitoneal lymph node ( RPLN ) recurrence of renal cell carcinoma ( RCC ) using a multicentre international cohort. Patients and Methods In all, 50 patients were identified who underwent resection of isolated RPLN recurrence of RCC at four institutions after nephrectomy for pT any N any M0 disease. Progression‐free ( PFS ) and cancer‐specific survival ( CSS ) were estimated using the Kaplan–Meier method. Cox proportional hazards regression models were used to assess the association of clinicopathological characteristics with disease progression. Results The median (interquartile range, IQR ) age at resection was 57.0 (50.0–62.5) years. The median ( IQR ) time to RPLN recurrence after nephrectomy was 12.6 (6.9–39.5) months, with no significant difference in median time to RPLN recurrence between patients with N+ disease at nephrectomy (10.7 [6.5–24.6] months) and those with Nx/pN0 disease at nephrectomy (13.7 [8.7–44.2] months) ( P = 0.66). The median ( IQR ) size of the RPLN recurrence before resection was 2.6 (1.9–5) cm. The most common site for RPLN recurrence was within the interaortocaval region (34%). The median ( IQR ) follow‐up after RPLN resection for patients alive at last follow‐up was 28.0 (13.7–51.2) months. During follow‐up, 26 patients developed RCC recurrence, at a median ( IQR ) of 9.9 (4.0–18.5) months after RPLN resection. Of those who developed a secondary recurrence, disease was again isolated to the retroperitoneum in seven patients. In all, 11 patients subsequently died, including 10 who died from disease. The median PFS after RPLN resection was 19.5 months, with a 3‐ and 5‐year PFS of 40.5% and 35.4%, respectively. We also found that RPLN recurrence at ≤12 months after nephrectomy was associated with a significantly inferior median PFS (12.3 months) compared with RPLN recurrence at >12 months after nephrectomy (47.6 months; P = 0.003). Moreover, on multivariate analysis, a shorter time to recurrence remained associated with a significantly increased risk for subsequent disease progression (hazard ratio 3.51; P = 0.005). Conclusion Surgical resection of isolated RPLN recurrence from RCC may result in durable cancer control in appropriately selected patients. Recurrence at ≤12 months after nephrectomy was associated with a significantly increased risk of progression after resection, underscoring the importance of this variable for risk stratification. Thus, we recommend that, in the setting of isolated RPLN recurrence of RCC (in patients without precluding comorbidities), careful consideration with the patients and medical oncology colleagues be undertaken about the relative and individualised benefits of surgical resection, systemic therapy, and surveillance.