Derazantinib alone and with atezolizumab in metastatic urothelial carcinoma with activating FGFR aberrations.

BACKGROUND: This Phase 1 b/2 study assessed the efficacy, in terms of objective response rate (ORR) of the FGFR1/2/3 kinase inhibitor derazantinib as monotherapy or in combination with atezolizumab in patients with metastatic urothelial cancer (mUC) and FGFR1-3 genetic aberrations (FGFR1-3GA). METHODS: This multicenter, open-label study comprised 5 substudies. In Substudies 1 and 5, patients with mUC with FGFR1-3GA received derazantinib monotherapy (300 mg QD in Substudy 1, 200 mg BID in Substudy 5). In Substudy 2, patients with any solid tumor received atezolizumab 1200 mg every 3 weeks plus derazantinib 200 or 300 mg QD. In Substudy 3, patients with mUC harboring FGFR1-3GA received derazantinib 200 mg BID plus atezolizumab 1200 mg every 3 weeks. In Substudy 4, patients with FGFR inhibitor-resistant mUC harboring FGFR1-3GA received derazantinib 300 mg QD monotherapy or derazantinib 300 mg QD plus atezolizumab 1200 mg every 3 weeks. RESULTS: The ORR for Substudies 1 and 5 combined was 4/49 (8.2%, 95% CI: 2.3, 19.6%), based on 4 partial responses. The ORR in Substudy 4 was 1/7 (14.3%, 95% CI: 0.4, 57.9%; 1 partial response for derazantinib 300 mg monotherapy, zero for derazantinib 300 mg plus atezolizumab 1200 mg). In Substudy 2, derazantinib 300 mg plus atezolizumab 1200 mg was identified as a recommended dose for Phase 2. Only 2 patients entered Substudy 3. CONCLUSIONS: Derazantinib as monotherapy or in combination with atezolizumab was well-tolerated but did not show sufficient efficacy to warrant further development in mUC.

Simulation of the effects of molecular urine markers in follow-up of patients with high-risk non-muscle invasive bladder cancer.

A plethora of urine markers for the management of patients with bladder cancer has been developed and studied in the past. However, the clinical impact of urine testing on patient management remains obscure. The goal of this manuscript is to identify scenarios for the potential use of molecular urine markers in the follow-up of patients with high-risk non-muscle-invasive BC (NMIBC) and estimate potential risks and benefits. Information on the course of disease of patients with high-risk NMIBC and performance data of a point-of-care test (UBC rapid™), an MCM-5 directed ELISA (ADXBLADDER™), and 2 additional novel assays targeting alterations of mRNA expression and DNA methylation (Xpert bladder cancer monitor™, Epicheck™) were retrieved from high-quality trials and/or meta-analyses. In addition, the sensitivity of white light cystoscopy (WLC) and the impact of a urine marker result on the performance of WLC were estimated based on fluorescence cystoscopy data and information from the CeFub trial. This information was applied to different scenarios in patient follow-up and sensitivity, estimated number of cystoscopies, and the numbers needed to diagnose were calculated. The sensitivity of guideline-based regular follow-up (SOC) at 1 year was calculated at 96%. For different marker-supported strategies sensitivities ranging from 77% to 97.9% were estimated. Calculations suggest that several strategies are effective for the SOC. While for the SOC 24.6 WLCs were required to diagnose 1 tumor recurrence (NND), this NND dropped below 5 in some marker-supported strategies. Based on the results of this simulation, a marker-supported follow-up of patients with HR NMIBC is safe and offers the option to significantly reduce the number of WLCs. Further research focusing on prospective randomized trials is needed to finally find a way to implement urine markers into clinical decision-making.

Interleukin-1ß/Interleukin (IL)-1-Receptor-Antagonist (IL1-RA) Axis in Invasive Bladder Cancer-An Exploratory Analysis of Clinical and Tumor Biological Significance.

Previous data indicate a role of IL-1 and IL-1RA imbalance in bladder carcinoma (BC); the inhibition of IL-1 signaling might be considered a treatment option. Objective: To assess expression patterns and the prognostic role of IL-1ß and IL-1RA in invasive BC and to evaluate their interaction with AKT signaling and proliferation. The study included two independent cohorts of n = 92 and n = 102 patients who underwent a radical cystectomy for BC. Specimen from BC and benign urothelium (n = 22 and n = 39) were processed to a tissue microarray and immunohistochemically stained for IL-1ß, IL-1RA, AKT, and Ki-67. Expression scores were correlated to clinical variables and Ki-67 and AKT expression. An association with outcome was assessed using Wilcoxon Kruskal-Wallis tests, Chi-square tests or linear regression, dependent on the variable's category. Kaplan-Meier and Cox proportional hazard analyses were used to estimate recurrence-free (RFS), cancer-specific (CSS) and overall survival (OS). Both IL-1ß and IL-1RA were significantly overexpressed in invasive BC compared to benign urothelium in both cohorts (p < 0.005). IL-1ß was associated with vascular invasion (210 vs. 183, p < 0.02), lymphatic invasion (210 vs. 180, <0.05) and G3 cancer (192 vs. 188, <0.04). The survival analysis revealed favorable RFS, CSS, and OS in the case of high IL-1ß expression (p < 0.02, <0.03, and <0.006, respectively). Multivariate analyses revealed an independent impact of (low) IL1ß expression on RFS, CSS, and OS. The IL-1ß and IL-1ß/IL-1RA ratios were positively correlated to the AKT expression (p < 0.05 and <0.01, respectively). Additionally, the high expression of Ki-67 (>15%) correlated with higher levels of IL-1ß (p = 0.01). The overexpression of IL-1ß and IL-1RA is frequently found in BC, with a prognostic significance observed for the IL-1ß protein expression. The observed link between the IL-1ß/IL-1RA axis and AKT signaling may indicate possible autophagy activation processes besides the known tumor-promoting effects of AKT.

Pembrolizumab and Enzalutamide in Patients with Abiraterone Acetate-Pretreated Metastatic Castration-Resistant Prostate Cancer: Cohort C of the Phase 1b/2 KEYNOTE-365 Study.

BACKGROUND: Limited responses have been observed in patients treated with enzalutamide after disease progression on abiraterone for metastatic castration-resistant prostate cancer (mCRPC), but androgen receptor signaling impacts T-cell function. OBJECTIVE: To evaluate the efficacy and safety of pembrolizumab plus enzalutamide in mCRPC. DESIGN, SETTING, AND PARTICIPANTS: Patients in cohort C of the phase 1b/2 KEYNOTE-365 study, who received ≥4 wk of treatment with abiraterone acetate in the prechemotherapy mCRPC state and experienced treatment failure or became drug-intolerant, were included. INTERVENTION: Pembrolizumab 200 mg intravenously every 3 wk plus enzalutamide 160 mg orally once daily. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The primary endpoints were safety, the confirmed prostate-specific antigen (PSA) response rate, and the objective response rate (ORR) according to Response Evaluation Criteria in Solid Tumors version 1.1 on blinded independent central review (BICR). Secondary endpoints included radiographic progression-free survival (rPFS) on BICR and overall survival (OS). RESULTS AND LIMITATIONS: A total of 102 patients received pembrolizumab plus enzalutamide. Median follow-up was 51 mo (interquartile range 37-56). The confirmed PSA response rate was 24% (95% confidence interval [CI] 16-33%). The confirmed ORR was 11% (95% CI 2.9-25%; 4/38 patients; two complete responses). Median rPFS was 6.0 mo (95% CI 4.1-6.3). Median OS was 20 mo (95% CI 17-24). Treatment-related adverse events (TRAEs) occurred in 94 patients (92%); grade 3-5 TRAEs occurred in 44 patients (43%). The incidence of treatment-related rash was higher with combination therapy than expected from the safety profile of each drug. One patient (1.0%) died of a TRAE (cause unknown). Study limitations include the single-arm design. CONCLUSIONS: Pembrolizumab plus enzalutamide had limited antitumor activity in patients who received prior abiraterone treatment without previous chemotherapy for mCRPC, with a safety profile consistent with the individual profiles of each agent. PATIENT SUMMARY: Pembrolizumab plus enzalutamide showed limited antitumor activity and manageable safety in patients with metastatic castration-resistant prostate cancer. The KEYNOTE-365 trial is registered on ClinicalTrials.gov as NCT02861573.

[Metastatic castration-resistant prostate cancer-emerging trends in therapy]. / Metastasiertes kastrationsresistentes Prostatakarzinom ­ Was kommt neues.

BACKGROUND: An increasing understanding of the cellular processes involved in growth, metastasis and development of resistance enable the development of new treatment strategies for advanced prostate cancer. OBJECTIVES: Using selected examples, the aim of this report is to present current developments to the reader and to give an outlook on possible upcoming changes in the treatment of advanced prostate cancer. MATERIALS AND METHODS: Narrative report based on expert consensus, supported by a literature search in PubMed (MEDLINE) and the abstract databases of the American Society of Clinical Oncology (ASCO) and European Society of Medical Oncology (ESMO). Examples were selected to illustrate current developments without claiming completeness. RESULTS: The androgen receptor (AR) signal transduction pathway remains a focus of scientific interest. Androgen synthesis inhibitors and AR degraders are promising new approaches to overcome resistance mediated by AR mutations or splice variants. Inhibition of key switch sites of alternative signaling pathways such as AKT or CDK4/6 provide additional treatment options, including combinational strategies through a tight linkage with the AR signaling pathway. A better understanding of tumor microenvironment and immune response is required for novel immunotherapeutic strategies using bispecific T­cell engagers (BiTEs) and chimeric antigen receptor (CAR) T cells. CONCLUSION: New treatment strategies give hope that we will be able to intervene even more effectively in the course of disease of advanced prostate cancer in the future. However, a major challenge, especially for the implementation of targeted treatment approaches, is likely to be the heterogeneity of tumor progression not only inter- but also intrapersonally.

Considering the Effects of Modern Point-of-Care Urine Biomarker Assays in Follow-Up of Patients with High-Risk Non-muscle-Invasive Bladder Cancer.

BACKGROUND: Although a plethora of urine markers for diagnosis and follow-up of patients with bladder cancer (BC) has been developed and studied, the clinical impact of urine testing on patient management remains unclear. The goal of this manuscript is to identify scenarios for a potential use of modern point-of-care (POC) urine marker assays in the follow-up of patients with high-risk non-muscle-invasive BC (NMIBC) and estimate potential risks and benefits. METHODS: To permit comparison between different assays, the results of 5 different POC assays studied in a recent prospective multicenter study including 127 patients with suspicious cystoscopy undergoing TURB were used for this simulation. For the current standard of care (SOC), a "marker-enforced" procedure, and a combined strategy sensitivity (Se), estimated number of cystoscopies, and the numbers needed to diagnose (NND) over a 1-year follow-up period were calculated. RESULTS: For regular cystoscopy (SOC), a Se of 91.7% and a NND of 42.2 repetitive office cystoscopies (WLCs) for 1 recurrent tumor at 1 year were calculated. For the "marker-enforced" strategy, marker sensitivities between 94.7% and 97.1% were observed. The "combined" strategy yielded for markers with a Se exceeding 50% an overall Se at 1 year similar or superior to the current SOC. Savings regarding the number of cystoscopies in the "marker-enforced" strategy vs. the SOC were small, while, depending on the marker, up to 45% of all cystoscopies may be saved using the "combined" strategy. CONCLUSIONS: Based on the results of this simulation, a marker-supported follow-up of patients with high-risk (HR) NMIBC is safe and offers options to significantly reduce the number of cystoscopies without compromising the Se. Further research focusing on prospective randomized trials is needed to finally find a way to include marker results into clinical decision-making.

Urine biomarkers in bladder cancer - current status and future perspectives.

Urine markers to detect bladder cancer have been the subject of research for decades. The idea that urine - being in continuous contact with tumour tissue - should provide a vector of tumour information remains an attractive concept. Research on this topic has resulted in a complex landscape of many different urine markers with varying degrees of clinical validation. These markers range from cell-based assays to proteins, transcriptomic markers and genomic signatures, with a clear trend towards multiplex assays. Unfortunately, the number of different urine markers and the efforts in research and development of clinical grade assays are not reflected in the use of these markers in clinical practice, which is currently limited. Numerous prospective trials are in progress with the aim of increasing the quality of evidence about urinary biomarkers in bladder cancer to achieve guideline implementation. The current research landscape suggests a division of testing approaches. Some efforts are directed towards addressing the limitations of current assays to improve the performance of urine markers for a straightforward detection of bladder cancer. Additionally, comprehensive genetic analyses are emerging based on advances in next-generation sequencing and are expected to substantially affect the potential application of urine markers in bladder cancer.

Differential Expression and Clinical Relevance of C-X-C Motif Chemokine Receptor 4 (CXCR4) in Renal Cell Carcinomas, Benign Renal Tumors, and Metastases.

C-X-C Motif Chemokine Receptor 4 (CXCR4) is part of the human chemokine system and involved in progression and metastasis in renal cell carcinoma (RCC). However, the role of CXCR4 protein expression in RCC remains controversial. In particular, data regarding the subcellular distribution of CXCR4 in RCC and RCC metastasis as well as CXCR4 expression in renal tumors of variant histology are limited. The aim of the present study was the evaluation of the differential CXCR4 expression in RCC primary tumor and metastatic tissue as well as in variant renal histologies. In addition, the prognostic capacity of CXCR4 expression in organ-confined clear cell RCC (ccRCC) was evaluated. Three independent renal tumor cohorts (primary ccRCC cohort n1 = 64; cohort of various histological entities n2 = 146; metastatic RCC tissue cohort n3 = 92) were evaluated using tissue microarrays (TMA). After immunohistochemical staining for CXCR4, nuclear and cytoplasmic expression patterns were evaluated. CXCR4 expression was correlated with validated pathologic prognosticators, clinical data, and overall and cancer-specific survival. Positive cytoplasmic staining was observed in 98% of the benign and 38.9% of the malignant samples. Nuclear staining was positive for 94.1% of the benign samples and 83% of the malignant samples. The median cytoplasmic expression score was found to be higher in benign tissue than in ccRCC (130.00 vs. 0.00); median nuclear expression score analysis indicated the opposite (56.0 vs. 71.0). Within malignant subtypes, the highest expression score was seen in papillary renal cell carcinomas (cytoplasmic: 117.50, nuclear: 41.50). Within benign renal tumors, high cytoplasmic and nuclear CXCR4 expression scores were seen for oncocytomas (cytoplasmic: 100.00, nuclear: 31.00). Expression scores in RCC metastasis ranked between benign renal tissue and ccRCC in cytoplasmic and nuclear expression. Cytoplasmic CXCR4 expression was identified as a prognostic factor for OS and CSS (p = 0.042; p = 0.019). Multivariate analysis including clinicopathological parameters did not reveal an independent prognostic character of CXCR4 expression. CXCR4 expression differs significantly within benign lesions and renal neoplasms. Cytoplasmic and nuclear expression of CXCR4 could be detected across all RCC subtypes. The prognostic value of CXCR4 in ccRCC was confirmed in univariate analysis.

Bladder preservation after neoadjuvant therapy - 2021 IBCN updates part 1.

The morbidity associated with radical cystectomy (RC) for muscle-invasive bladder cancer (MIBC) has fueled investigations into the feasibility of bladder preservation strategies after a favorable clinical response to neoadjuvant therapy (NAT). Identifying optimal candidates for bladder preservation is predicated on our ability to identify tumors with inherent cisplatin sensitivity and accurately stage patients before and after NAT. In the present review, we evaluate the accuracy and limitations of contemporary staging modalities and investigate clinical outcomes in patients with MIBC who were managed with bladder preservation after NAT. Lastly, we discuss the predictive role of cisplatin-sensitizing DNA damage response (DDR) gene alterations as a foundational component to current prospective clinical trials evaluating bladder preservation in the setting of MIBC.

25 years International Bladder Cancer Network (IBCN): The past, the present, and the future.

In 1997 an international group of scientists organized a meeting in Barcelona, Spain, to discuss the use of biomarkers in the management of patients with bladder cancer. This meeting was the offspring of an - initially informal - group that finally resulted in the foundation and incorporation of the International Bladder Cancer Network (IBCN) e.V. in 2005. Over the years the group has supported several research initiatives and generated several recommendations on the use of biomarkers in the diagnosis and treatment of bladder cancer. Meeting quality was generated by inviting experts presenting state-of-the-art lectures or work in progress reports, interdisciplinarity and the limited number of participants supporting an open and personal exchange resulted in a format increasingly attracting participants from all over the world. The recent limitations caused by the Covid-19 pandemic were partially met by organizing several well attended webinars. The future challenge is to maintain the IBCN meeting spirit despite an increasing interest of the scientific community and industrial partners to participate. However, the integration of and interaction between increasingly more specialized disciplines is a challenge that can be better catalyzed by an international multidisciplinary network than mostly national professional associations.

Discriminative capacity of guideline recommendations in the assessment of patients with asymptomatic microhematuria.

BACKGROUND & OBJECTIVE: Asymptomatic microhematuria (aMh) remains a diagnostic challenge in urological practice: while aMh is a risk factor of urothelial carcinoma (UC), prevalence of aMh is high. Guidelines were developed to permit risk stratification and reduce diagnostic workload. This study investigates the efficacy of several recommendations. MATERIAL & METHODS: Sixty hundred eight patients with newly diagnosed aMh without previous UC from an academic referral center (A; n = 320) and a private outpatient clinic (B; n = 288) were included. All patients underwent clinical workup including medical history, urine cytology, upper tract imaging and cystoscopy. Eleven former and current guidelines were applied to each patient individually; every patient was classified as either low risk (no further workup recommended) or high risk. Furthermore, a recently developed nomogram for hematuria assessment was included. RESULTS: The cohort comprised 142 females and 466 males (mean age 62 [range 18-92] years). Sixty-one patients (10.0%) were diagnosed with UC. Excluding the Swedish and recent NICE guideline generally advising against urologic workup, application of 9 other recommendations would have diagnosed all UCs and saved 1.6% to 16.1% of patients from workup. For the 2020 US guideline, solely applied to cohort B, 10.6% of patients were classified as low risk. The use of the nomogram would have saved 17.1% to 25% of patients from workup. CONCLUSIONS: Practical relevance of current guidelines is limited as they do not sufficiently identify patients not requiring clinical work up. Thus, guideline adherence may trigger overdiagnosis and even overtreatment. New ways of risk stratification are needed to improve aMh assessment.

Pembrolizumab plus Olaparib in Patients with Metastatic Castration-resistant Prostate Cancer: Long-term Results from the Phase 1b/2 KEYNOTE-365 Cohort A Study.

BACKGROUND: Pembrolizumab and olaparib have shown single-agent activity in patients with previously treated metastatic castration-resistant prostate cancer (mCRPC). OBJECTIVE: To evaluate the efficacy and safety of pembrolizumab plus olaparib in mCRPC. DESIGN, SETTING, AND PARTICIPANTS: Cohort A of the phase 1b/2 KEYNOTE-365 study enrolled patients with molecularly unselected, docetaxel-pretreated mCRPC whose disease progressed within 6 mo of screening. INTERVENTION: Pembrolizumab 200 mg intravenously every 3 wk plus olaparib 400-mg capsule or 300-mg tablet orally twice daily. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The primary endpoints were safety, confirmed prostate-specific antigen (PSA) response rate, and objective response rate (ORR) as per Response Evaluation Criteria in Solid Tumors (RECIST), version 1.1, by blinded independent central review. The secondary endpoints included radiographic progression-free survival (rPFS) and overall survival (OS). RESULTS AND LIMITATIONS: Of 104 enrolled patients, 102 were treated. The median age was 70 yr (interquartile range [IQR], 65-76), and 59 patients (58%) had measurable disease as per RECIST v1.1. The median time from the first dose to database cutoff was 24 mo (IQR, 22-47). The confirmed PSA response rate was 15%. The confirmed ORR was 8.5% (five partial responses) for patients with measurable disease. The median rPFS was 4.5 mo (95% confidence interval [CI], 4.0-6.5) and median OS was 14 mo (95% CI, 10.4-18.2). Clinical activity was consistent across the programmed death ligand 1 (PD-L1)-positive and homologous recombination repair mutation subgroups. Treatment-related adverse events (TRAEs) occurred in 93 patients (91%). Grade 3-5 TRAEs occurred in 49 patients (48%). Six deaths (5.9%) were due to adverse events; two (myocardial infarction and unknown cause) were attributed to treatment. Limitations of the study include the single-arm design. CONCLUSIONS: Pembrolizumab plus olaparib had a safety profile consistent with the profiles of the individual agents and demonstrated antitumor activity in previously treated patients with molecularly unselected, docetaxel-pretreated mCRPC. PATIENT SUMMARY: Pembrolizumab plus olaparib showed antitumor activity and expected safety in patients with metastatic castration-resistant prostate cancer.

Diabetes and the Prostate: Elevated Fasting Glucose, Insulin Resistance and Higher Levels of Adrenal Steroids in Prostate Cancer.

Although epidemiological studies suggest a lower prostate cancer incidence rate in patients with type 2 diabetes, cancer survival is markedly reduced. Underlying mechanisms that connect the two diseases are still unclear. Potential links between type 2 diabetes and prostate cancer are hallmarks of the metabolic syndrome, such as hyperglycemia and dyslipidemia. Therefore, we explored the systemic metabolism of 103 prostate cancer patients with newly diagnosed and yet untreated prostate cancer compared to 107 healthy controls, who were carefully matched for age and BMI. Here, we report that patients with prostate cancer display higher fasting blood glucose levels and insulin resistance, without changes in insulin secretion. With respect to lipid metabolism, serum triglyceride levels were lower in patients with prostate cancer. In addition, we report increased adrenal steroid biosynthesis in these patients. Our results indicate that higher fasting glucose levels in patients with prostate cancer may be explained at least in part by insulin resistance, due to the enhanced synthesis of adrenal steroids.

Prognostic Role of RNA Expression Molecular Biomarkers in Prostate and Bladder Cancers.

Prostate cancer and bladder cancer are two of the most common urologic cancers. Cancer risk stratification and prediction of prognosis have always been challenging. Following recent advances in genomic and proteomic technologies, several genomic biomarkers have been developed and proposed as a noninvasive and nonexpansive approach that can supplement our current data to improve prediction and accuracy. Several biomarkers have shown efficacy in patient risk stratification and in predicting prognosis. Here we provide a mini-review of current RNA biomarkers approved by the US Food and Drug Administration, including the Decipher, Oncotype DX Prostate, and Prolaris tests. We also provide a summary of their approved clinical utility in prostate cancer and bladder cancer management. PATIENT SUMMARY: A number of tests are available for measuring expression levels of genes related to prostate or bladder cancer. We review the usefulness of these tests in stratifying risk for patients and predicting their prognosis.

Expression Patterns and Corepressor Function of Retinoic Acid-induced 2 in Prostate Cancer.

BACKGROUND: Revealing molecular mechanisms linked to androgen receptor activity can help to improve diagnosis and treatment of prostate cancer. Retinoic acid-induced 2 (RAI2) protein is thought to act as a transcriptional coregulator involved in hormonal responses and epithelial differentiation. We evaluated the clinical relevance and biological function of the RAI2 protein in prostate cancer. METHODS: We assessed RAI2 gene expression in the Cancer Genome Atlas prostate adenocarcinoma PanCancer cohort and protein expression in primary tumors (n = 199) by immunohistochemistry. We studied RAI2 gene expression as part of a multimarker panel in an enriched circulating tumor cell population isolated from blood samples (n = 38) of patients with metastatic prostate cancer. In prostate cancer cell lines, we analyzed the consequences of androgen receptor inhibition on RAI2 protein expression and the consequences of RAI2 depletion on the expression of the androgen receptor and selected target genes. RESULTS: Abundance of the RAI2 protein in adenocarcinomas correlated with the androgen receptor; keratins 8, 18, and 19; and E-cadherin as well as with an early biochemical recurrence. In circulating tumor cells, detection of RAI2 mRNA significantly correlated with gene expression of FOLH1, KLK3, RAI2, AR, and AR-V7. In VCaP and LNCaP cell lines, sustained inhibition of hormone receptor activity induced the RAI2 protein, whereas RAI2 depletion augmented the expression of MME, STEAP4, and WIPI1. CONCLUSIONS: The RAI2 protein functions as a transcriptional coregulator of the androgen response in prostate cancer cells. Detection of RAI2 gene expression in blood samples from patients with metastatic prostate cancer indicated the presence of circulating tumor cells.

Urinary Tract Tumor Organoids Reveal Eminent Differences in Drug Sensitivities When Compared to 2-Dimensional Culture Systems.

Generation of organoids from urinary tract tumor samples was pioneered a few years ago. We generated organoids from two upper tract urothelial carcinomas and from one bladder cancer sample, and confirmed the expression of cytokeratins as urothelial antigens, vimentin as a mesenchymal marker, and fibroblast growth factor receptor 3 by immunohistochemistry. We investigated the dose response curves of two novel components, venetoclax versus S63845, in comparison to the clinical standard cisplatin in organoids in comparison to the corresponding two-dimensional cultures. Normal urothelial cells and tumor lines RT4 and HT1197 served as controls. We report that upper tract urothelial carcinoma cells and bladder cancer cells in two-dimensional cultures yielded clearly different sensitivities towards venetoclax, S63845, and cisplatin. Two-dimensional cultures were more sensitive at low drug concentrations, while organoids yielded higher drug efficacies at higher doses. In some two-dimensional cell viability experiments, colorimetric assays yielded different IC50 toxicity levels when compared to chemiluminescence assays. Organoids exhibited distinct sensitivities towards cisplatin and to a somewhat lesser extent towards venetoclax or S63845, respectively, and significantly different sensitivities towards the three drugs investigated when compared to the corresponding two-dimensional cultures. We conclude that organoids maintained inter-individual sensitivities towards venetoclax, S63845, and cisplatin. The preclinical models and test systems employed may bias the results of cytotoxicity studies.

[Poly(ADP-ribose) polymerase (PARP-)inhibitors as genetically based precision therapy in metastatic castration-resistent prostate cancer (mCRPC)]. / Poly-ADP-Ribose-Polymerase(PARP)-Inhibitoren als genetisch basierte Präzisionstherapie beim metastasierten kastrationsresistenten Prostatakarzinom (mCRPC).

With PARP inhibitors, the therapeutic landscape for metastatic castration-resistant prostate cancer (mCRPC) has been expanded by a new substance class since November 2020. Currently, the indication for this innovative therapy requires the presence of a mutation in one of the BRCA1/2 genes and prior hormonal therapy. This short review explains the molecular background and summarizes current clinical trials on PARP inhibition-also in combination with other therapy strategies. In view of positive data from the cited studies and the relatively high proportion of patients with "actionable" mutations, the personalized therapy concept of BRCA1/2 mutation-dependent PARP inhibition for mCRPC is now reflected in various guidelines including S3 guidelines.