Bayesian Interim Analysis and Efficiency of Phase III Randomized Trials.

IMPORTANCE: Improving the efficiency of interim assessments in phase III trials should reduce trial costs, hasten the approval of efficacious therapies, and mitigate patient exposure to disadvantageous randomizations. OBJECTIVE: We hypothesized that in silico Bayesian early stopping rules improve the efficiency of phase III trials compared with the original frequentist analysis without compromising overall interpretation. DESIGN: Cross-sectional analysis. SETTING: 230 randomized phase III oncology trials enrolling 184,752 participants. PARTICIPANTS: Individual patient-level data were manually reconstructed from primary endpoint Kaplan-Meier curves. INTERVENTIONS: Trial accruals were simulated 100 times per trial and leveraged published patient outcomes such that only the accrual dynamics, and not the patient outcomes, were randomly varied. MAIN OUTCOMES AND MEASURES: Early stopping was triggered per simulation if interim analysis demonstrated ≥ 85% probability of minimum clinically important difference/3 for efficacy or futility. Trial-level early closure was defined by stopping frequencies ≥ 0.75. RESULTS: A total of 12,451 simulations (54%) met early stopping criteria. Trial-level early stopping frequency was highly predictive of the published outcome (OR, 7.24; posterior probability of association, >99.99%; AUC, 0.91; P < 0.0001). Trial-level early closure was recommended for 82 trials (36%), including 62 trials (76%) which had performed frequentist interim analysis. Bayesian early stopping rules were 96% sensitive (95% CI, 91% to 98%) for detecting trials with a primary endpoint difference, and there was a high level of agreement in overall trial interpretation (Bayesian Cohen's κ, 0.95; 95% CrI, 0.92 to 0.99). However, Bayesian interim analysis was associated with >99.99% posterior probability of reducing patient enrollment requirements ( P < 0.0001), with an estimated cumulative enrollment reduction of 20,543 patients (11%; 89 patients averaged equally over all studied trials) and an estimated cumulative cost savings of 851 million USD (3.7 million USD averaged equally over all studied trials). CONCLUSIONS AND RELEVANCE: Bayesian interim analyses may improve randomized trial efficiency by reducing enrollment requirements without compromising trial interpretation. Increased utilization of Bayesian interim analysis has the potential to reduce costs of late-phase trials, reduce patient exposures to ineffective therapies, and accelerate approvals of effective therapies. KEY POINTS: Question: What are the effects of Bayesian early stopping rules on the efficiency of phase III randomized oncology trials?Findings: Individual-patient level outcomes were reconstructed for 184,752 patients from 230 trials. Compared with the original interim analysis strategy, in silico Bayesian interim analysis reduced patient enrollment requirements and preserved the original trial interpretation. Meaning: Bayesian interim analysis may improve the efficiency of conducting randomized trials, leading to reduced costs, reduced exposure of patients to disadvantageous treatments, and accelerated approval of efficacious therapies.

Pan-cancer subclonal mutation analysis of 7,827 tumors predicts clinical outcome.

Intra-tumor heterogeneity is an important driver of tumor evolution and therapy response. Advances in precision cancer treatment will require understanding of mutation clonality and subclonal architecture. Currently the slow computational speed of subclonal reconstruction hinders large cohort studies. To overcome this bottleneck, we developed Clonal structure identification through Pairwise Penalization, or CliPP, which clusters subclonal mutations using a regularized likelihood model. CliPP reliably processed whole-genome and whole-exome sequencing data from over 12,000 tumor samples within 24 hours, thus enabling large-scale downstream association analyses between subclonal structures and clinical outcomes. Through a pan-cancer investigation of 7,827 tumors from 32 cancer types, we found that high subclonal mutational load (sML), a measure of latency time in tumor evolution, was significantly associated with better patient outcomes in 16 cancer types with low to moderate tumor mutation burden (TMB). In a cohort of prostate cancer patients participating in an immunotherapy clinical trial, high sML was indicative of favorable response to immune checkpoint blockade. This comprehensive study using CliPP underscores sML as a key feature of cancer. sML may be essential for linking mutation dynamics with immunotherapy response in the large population of non-high TMB cancers.

Clinical Characteristics, Management, and Outcomes of Patients with Renal Medullary Carcinoma: A Single-center Retrospective Analysis of 135 Patients.

BACKGROUND AND OBJECTIVE: SMARCB1-deficient renal medullary carcinoma (RMC) is a rare kidney cancer associated with sickle cell hemoglobinopathies with poor outcomes described only in case reports and small series. We report disease and management characteristics as well as contemporary survival outcomes in a large cohort of patients with RMC. METHODS: Data were extracted retrospectively from all patients with RMC treated at MD Anderson Cancer Center between January 2003 and December 2023. Multivariable Cox regression was used to estimate overall survival (OS) by diagnosis period. KEY FINDINGS AND LIMITATIONS: Among 135 patients (median follow-up of 54.9 mo), only nine did not harbor a sickle hemoglobinopathy and were categorized as having renal cell carcinoma, unclassified with medullary phenotype (RCCU-MP). Most patients (78%) presented with metastatic disease, predominantly to the retroperitoneal lymph nodes (81.7%), and hematuria was the most frequent presenting symptom (60%) in RMC associated with sickle hemoglobinopathy. Survival outcomes improved by diagnosis year (adjusted hazard ratio 0.70, 95% confidence interval 0.53-0.92, p = 0.01). RCCU-MP occurred in slightly older patients with median OS of 19.5 mo from diagnosis, did not show a predilection to the right kidney or male predominance, and afflicted mainly Caucasians (89%). The study is limited by its retrospective nature conducted at one center. CONCLUSIONS AND CLINICAL IMPLICATIONS: RMC frequently presents with hematuria and is highly likely to spread to the retroperitoneal lymph nodes. Survival outcomes are improving with contemporary management. RCCU-MP is very rare and may be slightly less aggressive. PATIENT SUMMARY: Renal medullary carcinoma (RMC) is a rare and aggressive subtype of kidney cancer afflicting primarily young men and women of African descent. There exist limited data regarding patient demographics and disease characteristics. We reported our institution's experience in treating patients with RMC. The first symptom most patients with RMC reported was blood in the urine, and the most common places where the cancer spread were the lymph nodes around the kidney. Patients with RMC are living longer with contemporary treatments.

Durable Objective Response to Lurbinectedin in Small Cell Bladder Cancer with TP53 Mutation: A Molecular-Directed Strategy.

Small cell bladder cancer (SCBC) is a rare and aggressive disease, often treated with platinum/etoposide-based chemotherapy. Key molecular drivers include the inactivation of onco-suppressor genes (TP53, RB1) and amplifications in proto-oncogenes (MYC). We report a patient with SCBC who achieved an objective and prolonged response to lurbinectedin, which has been approved for metastatic small cell lung cancer, after developing disease progression on cisplatin/etoposide and nivolumab/ipilimumab. A genomic analysis of a metastatic biopsy prior to lurbinectedin initiation revealed a TP53 mutation and amplification of the cell cycle regulators E2F3 and MYCL. A repeat biopsy following the development of lurbinectedin resistance showed a new actionable ERBB2 alteration without significant change in the tumor mutation burden (six mutations/Mb). The present report suggests that lurbinectedin may be active and should be further explored in SCBC harboring TP53 mutations and amplifications in E2F3 and MYC family complexes.

Lost in the plot: missing visual elements in Kaplan-Meier plots of phase III oncology trials.

Missing visual elements (MVE) in Kaplan-Meier (KM) curves can misrepresent data, preclude curve reconstruction, and hamper transparency. This study evaluated KM plots of phase III oncology trials. MVE were defined as an incomplete y-axis range or missing number at risk table in a KM curve. Surrogate endpoint KM curves were additionally evaluated for complete interpretability, defined by (1) reporting the number of censored patients and (2) correspondence of the disease assessment interval with the number at risk interval. Among 641 trials enrolling 518 235 patients, 116 trials (18%) had MVE in KM curves. Industry sponsorship, larger trials, and more recently published trials were correlated with lower odds of MVE. Only 3% of trials (15 of 574) published surrogate endpoint KM plots with complete interpretability. Improvements in the quality of KM curves of phase III oncology trials, particularly for surrogate endpoints, are needed for greater interpretability, reproducibility, and transparency in oncology research.

Differential Treatment Effects of Subgroup Analyses in Phase 3 Oncology Trials From 2004 to 2020.

Importance: Subgroup analyses are often performed in oncology to investigate differential treatment effects and may even constitute the basis for regulatory approvals. Current understanding of the features, results, and quality of subgroup analyses is limited. Objective: To evaluate forest plot interpretability and credibility of differential treatment effect claims among oncology trials. Design, Setting, and Participants: This cross-sectional study included randomized phase 3 clinical oncology trials published prior to 2021. Trials were screened from ClinicalTrials.gov. Main Outcomes and Measures: Missing visual elements in forest plots were defined as a missing point estimate or use of a linear x-axis scale for hazard and odds ratios. Multiplicity of testing control was recorded. Differential treatment effect claims were rated using the Instrument for Assessing the Credibility of Effect Modification Analyses. Linear and logistic regressions evaluated associations with outcomes. Results: Among 785 trials, 379 studies (48%) enrolling 331 653 patients reported a subgroup analysis. The forest plots of 43% of trials (156 of 363) were missing visual elements impeding interpretability. While 4148 subgroup effects were evaluated, only 1 trial (0.3%) controlled for multiple testing. On average, trials that did not meet the primary end point conducted 2 more subgroup effect tests compared with trials meeting the primary end point (95% CI, 0.59-3.43 tests; P = .006). A total of 101 differential treatment effects were claimed across 15% of trials (55 of 379). Interaction testing was missing in 53% of trials (29 of 55) claiming differential treatment effects. Trials not meeting the primary end point were associated with greater odds of no interaction testing (odds ratio, 4.47; 95% CI, 1.42-15.55, P = .01). The credibility of differential treatment effect claims was rated as low or very low in 93% of cases (94 of 101). Conclusions and Relevance: In this cross-sectional study of phase 3 oncology trials, nearly half of trials presented a subgroup analysis in their primary publication. However, forest plots of these subgroup analyses largely lacked essential features for interpretation, and most differential treatment effect claims were not supported. Oncology subgroup analyses should be interpreted with caution, and improvements to the quality of subgroup analyses are needed.

Charting the Path to Systemic Therapy De-escalation-Oligometastatic Kidney Cancer as a Paradigm.

This Viewpoint discusses whether select patient populations may benefit from de-escalation rather than escalation of systemic therapy for kidney cancer.

Efficacy, Safety, and Tolerability of Tivozanib in Heavily Pretreated Patients With Advanced Clear Cell Renal Cell Carcinoma.

BACKGROUND: Tivozanib has been approved as a third-line or later therapy for advanced renal cell carcinoma based on the TIVO-3 trial, which was conducted before immune checkpoint therapies (ICT), cabozantinib, and lenvatinib/everolimus became incorporated in the current sequential treatment paradigm for advanced clear cell RCC (ccRCC). METHODS: We performed a retrospective study of patients with advanced ccRCC treated with tivozanib at MD Anderson Cancer Center during 6/2021-7/2023. A blinded radiologist assessed tumor response by RECIST v1.1. We assessed overall response rate (ORR), clinical benefit rate (CBR) [percentage of all treated patients who achieved radiologic response or stable disease (SD) for ≥ 6 months], progression-free survival (PFS), overall survival (OS), and safety. RESULTS: Of 30 analyzed patients, 23% had performance status ≥ 2; 47% had International Metastatic RCC Database Consortium (IMDC) poor-risk disease. Median number of prior therapies was 4 (range 1-8). All patients received prior ICT, 87% cabozantinib and 60% lenvatinib ± everolimus. Of 26 evaluable patients, 2 patients had confirmed partial response (ORR 7.7%); 5 patients had SD for ≥ 6 months (CBR 23.3%). Median PFS was 3.8 months (range 0.7-13.9); median OS was 14.1 months (range 0.3-28.5). Fifteen patients (50%) had ≥ 1 treatment-related adverse event (TRAE). There were 6 grade ≥ 3 TRAEs [hypertension, congestive heart failure (3), mucositis, and GI perforation (grade 5)]. CONCLUSIONS: In this cohort of heavily pretreated patients with advanced ccRCC, tivozanib yielded a modest clinical benefit in a minority of patients who received prior ICT, cabozantinib, and lenvatinib ± everolimus. TRAEs were consistent with previously published reports.

Association of differential censoring with survival and suboptimal control arms among oncology clinical trials.

Differential censoring, which refers to censoring imbalance between treatment arms, may bias the interpretation of survival outcomes in clinical trials. In 146 phase III oncology trials with statistically significant time-to-event surrogate primary endpoints, we evaluated the association between differential censoring in the surrogate primary endpoints, control arm adequacy, and the subsequent statistical significance of overall survival results. Twenty-four (16%) trials exhibited differential censoring that favored the control arm, whereas 15 (10%) exhibited differential censoring that favored the experimental arm. Positive overall survival was more common in control arm differential censoring trials (63%) than in trials without differential censoring (37%) or with experimental arm differential censoring (47%; odds ratio = 2.64, 95% confidence interval = 1.10 to 7.20; P = .04). Control arm differential censoring trials more frequently used suboptimal control arms at 46% compared with 20% without differential censoring and 13% with experimental arm differential censoring (odds ratio = 3.60, 95% confidence interval = 1.29 to 10.0; P = .007). The presence of control arm differential censoring in trials with surrogate primary endpoints, especially in those with overall survival conversion, may indicate an inadequate control arm and should be examined and explained.

The IL6/JAK/STAT3 signaling axis is a therapeutic vulnerability in SMARCB1-deficient bladder cancer.

SMARCB1 loss has long been observed in many solid tumors. However, there is a need to elucidate targetable pathways driving growth and metastasis in SMARCB1-deficient tumors. Here, we demonstrate that SMARCB1 deficiency, defined as genomic SMARCB1 copy number loss associated with reduced mRNA, drives disease progression in patients with bladder cancer by engaging STAT3. SMARCB1 loss increases the chromatin accessibility of the STAT3 locus in vitro. Orthotopically implanted SMARCB1 knockout (KO) cell lines exhibit increased tumor growth and metastasis. SMARCB1-deficient tumors show an increased IL6/JAK/STAT3 signaling axis in in vivo models and patients. Furthermore, a pSTAT3 selective inhibitor, TTI-101, reduces tumor growth in SMARCB1 KO orthotopic cell line-derived xenografts and a SMARCB1-deficient patient derived xenograft model. We have identified a gene signature generated from SMARCB1 KO tumors that predicts SMARCB1 deficiency in patients. Overall, these findings support the clinical evaluation of STAT3 inhibitors for the treatment of SMARCB1-deficient bladder cancer.

Locoregional Therapies in Immunologically "Cold" Tumors: Opportunities and Clinical Trial Design Considerations.

Immunotherapy has revolutionized cancer management, but many tumors, particularly immunologically "cold" tumors, remain resistant to the therapy. The combination of conventional systemic immunotherapies and locoregional interventional radiology approaches is being explored to transform these cold tumors into immunologically active "hot" ones. The present article uses the example of chromophobe renal cell carcinoma (ChRCC), a renal cell carcinoma subtype resistant to current systemic immunotherapies, to address practical and conceptual challenges that have prevented the activation of clinical trials specifically designed for this malignancy to date. The practical framework discussed herein can help overcome logistic and funding limitations and facilitate the development of biology-informed clinical trials tailored to specific rare diseases such as ChRCC.

The immune-related adverse events paradox in locally advanced or metastatic urothelial cancer after atezolizumab immunotherapy: analysis of individual patient data from IMvigor210 and IMvigor211 trials.

OBJECTIVE: To investigate the association between immune-related adverse events (irAEs) and oncological outcomes in patients with advanced urothelial cancer receiving immune checkpoint inhibitors (ICIs), and whether the administration of systemic corticosteroids diminishes therapeutic impact. PATIENTS AND METHODS: The association between irAEs occurrence and clinical progression-free survival (PFS), overall survival (OS), and cancer-specific survival (CSS) was tested by means of multivariable Cox or competing-risks regression, when appropriate. Patients experiencing irAEs were further stratified based on systemic corticosteroids administration. A sensitivity analysis was conducted by repeating all the analyses with median time to irAE as landmark point. RESULTS: We relied on individual participant data from two prospective trials for advanced urothelial cancer: IMvigor210 and IMvigor211. A total of 896 patients who received atezolizumab for locally advanced or metastatic urothelial cancer were considered. Overall, irAEs were recorded in 195 patients and the median time to irAEs was 64 days. On multivariable analysis, irAEs were inversely associated with the risk of disease progression (hazard ratio [HR] 0.50, 95% confidence interval [CI] 0.40-0.61; P < 0.001), overall mortality (HR 0.51, 95% CI 0.41-0.64; P < 0.001), and cancer-specific mortality (subdistributional HR [sHR] 0.55, 95% CI 0.45-0.72; P < 0.001). Moreover, our results did not refute the supposition that the administration of systemic corticosteroids does not impact oncological outcomes (PFS: HR 0.92, 95% CI 0.62-1.34, P = 0.629; OS: HR 0.86, 95% CI 0.51-1.64, P = 0.613; CSS: sHR 0.90, 95% CI 0.60-1.36, P = 0.630). The sensitivity analysis confirmed our findings. CONCLUSIONS: The development of irAEs while receiving atezolizumab treatment was associated with improved oncological outcomes, namely overall and cancer-specific mortality, and PFS. These findings seem to not be substantially affected by administration of systemic corticosteroids.

Risk-benefit trade-offs and precision utilities in phase I-II clinical trials.

BACKGROUND: Identifying optimal doses in early-phase clinical trials is critically important. Therapies administered at doses that are either unsafe or biologically ineffective are unlikely to be successful in subsequent clinical trials or to obtain regulatory approval. Identifying appropriate doses for new agents is a complex process that involves balancing the risks and benefits of outcomes such as biological efficacy, toxicity, and patient quality of life. PURPOSE: While conventional phase I trials rely solely on toxicity to determine doses, phase I-II trials explicitly account for both efficacy and toxicity, which enables them to identify doses that provide the most favorable risk-benefit trade-offs. It is also important to account for patient covariates, since one-size-fits-all treatment decisions are likely to be suboptimal within subgroups determined by prognostic variables or biomarkers. Notably, the selection of estimands can influence our conclusions based on the prognostic subgroup studied. For example, assuming monotonicity of the probability of response, higher treatment doses may yield more pronounced efficacy in favorable prognosis compared to poor prognosis subgroups when the estimand is mean or median survival. Conversely, when the estimand is the 3-month survival probability, higher treatment doses produce more pronounced efficacy in poor prognosis compared to favorable prognosis subgroups. METHODS AND CONCLUSIONS: Herein, we first describe why it is essential to consider clinical practice when designing a clinical trial and outline a stepwise process for doing this. We then review a precision phase I-II design based on utilities tailored to prognostic subgroups that characterize efficacy-toxicity risk-benefit trade-offs. The design chooses each patient's dose to optimize their expected utility and allows patients in different prognostic subgroups to have different optimal doses. We illustrate the design with a dose-finding trial of a new therapeutic agent for metastatic clear cell renal cell carcinoma.

A Phase 2 Study of Sitravatinib in Combination with Nivolumab in Patients with Advanced or Metastatic Urothelial Carcinoma.

BACKGROUND AND OBJECTIVE: Checkpoint inhibitor therapy (CPI) has demonstrated survival benefits in urothelial carcinoma (UC); however, not all patients benefit from CPI due to resistance. Combining sitravatinib, a multitargeted receptor tyrosine kinase inhibitor of TYRO3, AXL, and MERTK (TAM) receptors and VEGFR2, with CPI may improve antitumor responses. Our objective was to assess the efficacy and safety of sitravatinib plus nivolumab in patients with advanced/metastatic UC. METHODS: The 516-003 trial (NCT03606174) is an open-label, multicohort phase 2 study evaluating sitravatinib plus nivolumab in patients with advanced/metastatic UC enrolled in eight cohorts depending on prior treatment with CPI, platinum-based chemotherapy (PBC), or antibody-drug conjugate (ADC). Overall, 244 patients were enrolled and treated with sitravatinib plus nivolumab (median follow-up 14.1-38.2 mo). Sitravatinib (free-base capsules 120 mg once daily [QD] or malate capsule 100 mg QD) plus nivolumab (240 mg every 2 wk/480 mg every 4 wk intravenously). KEY FINDINGS AND LIMITATIONS: The primary endpoint was objective response rate (ORR; RECIST v1.1). The secondary endpoints included progression-free survival (PFS) and safety. The Predictive probability design and confidence interval methods were used. Among patients previously treated with PBC, ORR, and median PFS were 32.1% and 3.9 mo in CPI-naïve patients (n = 53), 14.9% and 3.9 mo in CPI-refractory patients (n = 67), and 5.4% and 3.7 mo in CPI- and ADC-refractory patients (n = 56), respectively. Across all cohorts, grade 3 treatment-related adverse events (TRAEs) occurred in 51.2% patients and grade 4 in 3.3%, with one treatment-related death (cardiac failure). Immune-related adverse events occurred in 50.4% patients. TRAEs led to sitravatinib/nivolumab discontinuation in 6.1% patients. CONCLUSIONS AND CLINICAL IMPLICATIONS: Sitravatinib plus nivolumab demonstrated a manageable safety profile but did not result in clinically meaningful ORRs in patients with advanced/metastatic UC in the eight cohorts studied. PATIENT SUMMARY: In this study, the combination of two anticancer drugs, sitravatinib and nivolumab, resulted in manageable side effects but no meaningful responses in patients with bladder cancer.

The Influence of Obesity on Outcomes with Immune Checkpoint Blockade: Clinical Evidence and Potential Biological Mechanisms.

Immune checkpoint blockade (ICB) is a mainstay of treatment for advanced cancer, yet tumor response and host toxicity are heterogenous in those patients who receive ICB. There is growing interest in understanding how host factors interact with tumor intrinsic properties and the tumor microenvironment to influence the therapeutic index with ICB. Obesity, defined by body mass index, is a host factor associated with improved outcomes in select cancers when treated with ICB. While the biological mechanism for this obesity paradox is not fully understood, pre-clinical and translational studies suggest obesity may potentially impact tumor metabolism, inflammation, and angiogenesis. Herein, we summarize clinical studies that support an obesity paradox with ICB, explore potential biological mechanisms that may account for the obesity paradox, and address methodological challenges to consider when studying obesity and treatment outcomes.

Treatment Outcomes in Patients With Metastatic Renal Cell Carcinoma With Sarcomatoid and/or Rhabdoid Dedifferentiation After Progression on Immune Checkpoint Therapy.

BACKGROUND: Metastatic RCC with sarcomatoid and/or rhabdoid (S/R) dedifferentiation is an aggressive disease associated with improved response to immune checkpoint therapy (ICT). The outcomes of patients treated with VEGFR-targeted therapies (TT) following ICT progression have not been investigated. PATIENTS AND METHODS: Retrospective review of 57 patients with sarcomatoid (S), rhabdoid (R), or sarcomatoid plus rhabdoid (S + R) dedifferentiation who received any TT after progression on ICT at an academic cancer center. Clinical endpoints of interest included time on TT, overall survival (OS) from initiation of TT, and objective response rate (ORR) by RECIST version 1.1. Multivariable models adjusted for epithelial histology, IMDC risk, prior VEGFR TT, and inclusion of cabozantinib in the post-ICT TT regimen. RESULTS: 29/57 patients had S dedifferentiation and 19 had R dedifferentiation. The most frequently used TT was cabozantinib (43.9%) followed by selective VEGFR TT (22.8%). The median time on TT was 6.4 months for all, 6.1 months for those with S dedifferentiation, 15.6 months for R dedifferentiation, and 6.1 months for S + R dedifferentiation. Median OS from initiation of TT was 24.9 months for the entire cohort, and the ORR was 20.0%. Patients with R dedifferentiation had significantly longer time on TT than those with S dedifferentiation (HR 0.44, 95% CI, 0.21-0.94). IMDC risk was associated with OS. CONCLUSIONS: A subset of patients with S/R dedifferentiation derive clinical benefit from TT after they have progressive disease on ICT. Patients with R dedifferentiation appeared to derive more benefit from TT than those with S dedifferentiation.

Müllerian-Type Clear Cell Carcinoma of Donor Origin in a Male Patient with a Kidney Transplant: Ascertained by Molecular Testing.

Clear cell carcinomas of Müllerian origin have a strong female predominance and only extremely rarely will arise within the kidney, presumably due to ectopic Müllerian embryogenesis. Herein, we report a unique case of metastatic Müllerian type clear cell carcinoma in a 37-year-old patient who had previously received a transplanted kidney from his father at age 11 (due to severe bilateral vesicoureteral reflux) and remained on chronic immunosuppression. The tumor was highly aggressive and demonstrated somatic mutations in NF2 and SETD2. Imaging of the transplanted kidney did not reveal any clear evidence of malignancy. However, targeted multigene sequencing and short tandem repeat testing revealed that the cancer was of donor origin, presumably from ectopic Müllerian tissue transplanted to the patient along with the kidney graft. The tumor was resistant to first-line therapy with a triple combination of carboplatin plus paclitaxel plus bevacizumab, as well as to second-line immunotherapy with nivolumab plus ipilimumab after tapering down the patient's immunosuppression. Despite the tumor being genetically distinct from the host, the use of immune checkpoint therapy with nivolumab plus ipilimumab did not yield a response. This unique case showcases the value of molecular testing in determining the tumor origin in patients with solid organ transplants who present with cancers of unknown primary. This can prompt the potential investigation of other recipients from the same donor.

Comparative Effectiveness Analysis of Treatment Strategies for Surgically Resectable Neuroendocrine Carcinoma of the Urinary Tract.

BACKGROUND: Neoadjuvant chemotherapy (neoCTX) has been recommended as the optimal strategy in surgically resectable neuroendocrine carcinoma (NEC) of the urinary tract (NEC-URO). OBJECTIVE: To determine the systemic therapy regimen and timing, which are most active against NEC-URO. DESIGN, SETTING, AND PARTICIPANTS: We used our institutional historical clinical and pathological database to study 203 patients (cT2, 74%; cT3/4a, 22%; and cTx, 4%) with surgically resectable NEC-URO between November 1985 and May 2020. A total of 141 patients received neoCTX and 62 underwent initial radical surgery, 24 of whom received adjuvant CTX (adjCTX). INTERVENTION: Neoadjuvant CTX with etoposide/cisplatin (EP), an alternating doublet of ifosfamide/doxorubicin (IA) and EP, dose-dense methotrexate/vinblastine/doxorubicin/cisplatin (MVAC), gemcitabine/cisplatin (GC), or others. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Overall survival (OS), downstaging rate, and pathological complete response using a multivariable model adjusting for tumor- and patient-related factors. RESULTS AND LIMITATIONS: Downstaging rate was significantly improved with neoCTX versus initial surgery (49.6% vs 14.5%, p < 0.0001), stage cT2N0 versus cT3/4N0 (44% vs 25%, p = 0.01), or presence of carcinoma in situ (47% vs 28%, p = 0.01). Downstaging was greatest with IA/EP (65%) versus EP (39%), MVAC/GC (27%), or others (36%, p = 0.04). After adjusting for age and Eastern Cooperative Oncology Group performance status, IA/EP was still associated with improved downstaging (odds ratio = 3.7 [1.3-10.2], p = 0.01). At a median follow-up of 59.7 mo, 5-yr OS rates for neoCTX followed by surgery, surgery alone, and surgery followed by adjCTX were 57%, 22%, and 30%, respectively. An NEC regimen (IA/EP or EP) versus a urothelial regimen (MVAC/GC or others) was associated with improved survival (145.4 vs 42.5 mo, hazard ratio = 0.49, 95% confidence interval: 0.25-0.94). CONCLUSIONS: Neoadjuvant CTX remains the standard-of-care treatment for NEC-URO with an advantage for NEC regimens over traditional urothelial regimens. IA/EP improves pathological downstaging at the time of surgery compared with EP, but is reserved for younger and higher function patients. PATIENT SUMMARY: In this report, we looked at the outcomes from invasive neuroendocrine carcinoma of the urinary tract in a large US population. We found that the outcomes varied with treatment strategy. We conclude that the best outcomes are seen in patients treated with chemotherapy prior to surgery and regimens tailored to histology and tolerance.