Boorjian, Stephen A.

695 Background: Small cell carcinoma of the bladder (SCCB) is a rare variant of bladder cancer with limited data informing prognosis. We present a novel prognostic model for disease specific survival (DSS) for patients with non-metastatic (M0) SCCB, derived from the Surveillance, Epidemiology and End Results (SEER) database. Methods: The SEER database (18 registries/November 2020) was queried with the ICD-10 topography codes C67.0-C67.9 (bladder), and the morphologic code 8041 (SCCB). Eligible patients (adults, histologic confirmation, available follow-up/staging data, M0) were randomly divided into a training (TC) and a validation cohort (VC) (7:3 ratio). Variables significantly associated with DSS were identified with multivariate Cox regression and backwards stepwise conditional approach and inserted in the model. Points were assigned to each variable based on the formula: Probability of an event at time t=S0(t)exp(β1x1, β2x2...), (β = regression coefficients, x = observed covariate values, S0(t) = survival function). Cumulative risk points were assigned to each patient and three distinct risk categories for DSS were constructed. Harrel’s C-statistic with bootstrap resampling was used for internal (TC) and external (VC) validation. Model performance was compared to the AJCC 8th edition (likelihood ratio test -LRT). Results: A total of 1039 patients were included (739 TC, 300 VC). No statistically significant differences in baseline characteristics/survival outcomes were identified between TC and VC. Age (years), T/N stage, radical cystectomy, chemotherapy, and radiation were significant variables inserted in the multivariate model (table). Patients were stratified to three risk groups (low, intermediate, high) based on the total cumulative risk points collected. Median DSS was NR (95%CI; NR, NR), 25 (95% CI; 18-32) and 9 months (95% CI; 7-11) for the low, intermediate, and high-risk category, log-rank p<.001. Harrel's C-statistic for the model was 0.70 (95%CI;0.67-0.73) in the TC and 0.66 (95%CI; 0.61-0.71) in the VC. In comparison, C-statistic for the AJCC 8th edition was 0.56 (95% CI; 0.52-0.59) and 0.53 (95% CI; 0.51 to 0.57), respectively. The LRT demonstrated superior performance of the model compared to AJCC (p<.001). Conclusions: We present a novel prognostic model for DSS in patients with locoregional SCCB composed of variables readily available in daily practice, which may serve as a useful tool for individualized risk assessment of patients with this rare malignancy. Further validation in prospective studies/clinical trials is warranted. [Table: see text]

572 Background: Bladder preservation with trimodal therapy (TMT), which consists of maximal transurethral resection of bladder tumors followed by chemoradiation, is now included in guidelines with radical cystectomy (RC) as options for definitive management of muscle-invasive bladder cancer (MIBC). Prospective randomized controlled trial data to help guide treatment selection are lacking, and prior efforts to bridge this knowledge gap have failed primarily due to poor accrual. A recent retrospective analysis comparing TMT to RC reported similar oncologic outcomes between these treatments when performed in highly selected patients. However, treatment toxicities and costs vary significantly between these management options. To investigate the impact of these outcomes on relative treatment value, we evaluated the comparative cost-effectiveness of TMT and RC for treatment of MIBC. Methods: Cost-effectiveness was compared between TMT and RC for patients with a solitary, muscle-invasive tumor less than 7cm, no or unilateral hydronephrosis, limited carcinoma in situ, and adequate bladder function (criteria utilized in a recent retrospective comparative series) using a microsimulation model with a 5-year horizon from a Medicare payer perspective. Additionally, a 10-year lifetime horizon was evaluated to better understand the impact of long-term outcome uncertainty on cost-effectiveness. Based on recently published multicenter retrospective propensity score matched data, metastatic progression and survival probabilities were assumed to be equivalent between treatments. Utility values and additional probabilities, including both short and long-term treatment toxicities, were obtained from published literature. Primary outcomes of interest included effectiveness measured in quality adjusted life years (QALYs) and incremental cost-effectiveness ratios (ICER) using a willingness-to-pay threshold of $100,000/QALY. One-way and probabilistic sensitivity analyses were performed to assess the robustness of the model. Results: At 5 years, the average cost was $32,286.35 higher for TMT versus RC. The average QALYs were 3.88 and 3.96 for RC and TMT respectively. TMT was not cost-effective at 5-year (ICER: $379,917.21/QALY) or 10-year (ICER: $222,704.78/QALY) time horizons. On one-way sensitivity analyses, TMT would become cost effective if: 1) TMT costs were less than $16,152; or 2) TMT resulted in a 13.3% improvement in metastasis free survival relative to RC. Conclusions: Although it resulted in similar quality and duration of life, TMT was not cost-effective relative to RC at 5 and 10 years given higher treatment costs. These findings support the role of both TMT and RC in management of MIBC and highlight the need for continued efforts to reduce healthcare costs associated with TMT.

381 Background: Venous tumor thrombus (VTT) is associated with worse oncologic outcomes in clear cell renal cell carcinoma (ccRCC). It is unknown if VTT and pulmonary embolism (PE) predispose patients to pulmonary metastasis. Methods: We queried our institutional registry for ccRCC patients undergoing radical nephrectomy (1970-2019). Cox proportional hazards regression models, adjusting for factors associated with ccRCC progression, were used to determine if VTT and PE were associated with pulmonary metastasis. Results: Of 3,410 patients studied, 1,025 (30%) had VTT, and patients with VTT were more likely to present with pulmonary metastasis at nephrectomy (20% vs 7%, p<0.001). Within the VTT subset, level of VTT was not significantly associated with pulmonary metastasis at nephrectomy (p=0.3). For all patients who had metastatic disease at nephrectomy (n=643), pulmonary metastasis was more common in those with VTT versus those without VTT (68% vs 51%, p<0.001). Excluding patients with pulmonary metastasis at nephrectomy, on multivariable analysis, VTT remained associated with post-nephrectomy pulmonary metastasis (hazard ratio (HR) 1.31, p<0.001) without a notable difference in HRs between renal vein (1.27) and caval (1.38) VTT. Presence of PE in the setting of VTT was associated with increased pulmonary metastasis post-nephrectomy (HR 2.31, p<0.001). Conclusions: VTT is associated with disproportionately increased pulmonary metastasis at presentation and post-nephrectomy in ccRCC patients. Further, the presence of PE at nephrectomy for VTT was associated with increased pulmonary metastasis post-nephrectomy. These results support a metastatic predilection of ccRCC with VTT to the lungs.

Robotic-assisted radical prostatectomy (RARP) has become the leading approach for radical prostatectomy driven by innovations aimed at improving functional and oncological outcomes. The initial advancement in this field was transperitoneal multiport robotics, which has since undergone numerous technical modifications. These enhancements include the development of extraperitoneal, transperineal, and transvesical approaches to radical prostatectomy, greatly facilitated by the advent of the Single Port (SP) robot. This review offers a comprehensive analysis of these evolving techniques and their impact on RARP. Additionally, we explore the transformative role of artificial intelligence (AI) in digitizing robotic prostatectomy. AI advancements, particularly in automated surgical video analysis using computer vision technology, are unprecedented in their scope. These developments hold the potential to revolutionize surgeon feedback and assessment and transform surgical documentation, and they could lay the groundwork for real-time AI decision support during surgical procedures in the future. Furthermore, we discuss future robotic platforms and their potential to further enhance the field of RARP. Overall, the field of minimally invasive radical prostatectomy for prostate cancer has been an incubator of innovation over the last two decades. This review focuses on some recent developments in robotic prostatectomy, provides an overview of the next frontier in AI innovation during prostate cancer surgery, and highlights novel robotic platforms that may play an increasing role in prostate cancer surgery in the future.

Abstract Background The Surgery in Early Metastatic Seminoma (SEMS) trial examined retroperitoneal lymph node dissection as first-line treatment for patients with isolated 1-3 cm retroperitoneal lymphadenopathy. To date, the standard of care for these patients has been either chemotherapy or radiotherapy. Herein, we evaluated the relative cost-effectiveness of these management strategies. Methods A microsimulation model assessed the cost-effectiveness of retroperitoneal lymph node dissection, chemotherapy, and radiotherapy for stage IIA seminoma. Sensitivity analyses were performed to evaluate model robustness. Retroperitoneal lymph node dissection recurrence probabilities were obtained from the SEMS trial. All other probability and utility values were obtained from published literature. Primary outcomes included costs from a commercial insurer’s perspective, effectiveness (quality adjusted life-years [QALYs]), and incremental cost-effectiveness ratios using a willingness-to-pay threshold of $100 000/QALY. Results At a lifetime horizon, the mean costs per patient for retroperitoneal lymph node dissection, radiotherapy, and chemotherapy were $58 469, $98 783, and $104 096, and the mean QALYs were 40.61, 40.70, and 39.15, respectively. Retroperitoneal lymph node dissection was found to be the most cost-effective approach because of high costs and accrued disutility of chronic toxicities associated with radiotherapy (cost-effectiveness ratios = $433 845/QALY) and chemotherapy (dominated). On 1-way sensitivity analyses, retroperitoneal lymph node dissection was no longer cost-effective if the probabilities of infertility and cardiovascular toxicity after radiotherapy were less than 13% and 16%, respectively, or if the 2-year probability of progression after retroperitoneal lymph node dissection was more than 26%. Conclusions Retroperitoneal lymph node dissection was the most cost-effective treatment approach for stage IIA seminoma. These findings support clinical guideline consideration of including retroperitoneal lymph node dissection as a treatment option for well-selected patients with stage IIA seminoma.