Serum PD-L1 (sPD-L1) levels are associated with prognosis in various tumors but has not yet been investigated in advanced bladder cancer. We assessed pretreatment serum samples from 83 BC patients who received platinum chemotherapy and from 12 patients who underwent immune checkpoint inhibitor (ICI) therapy. In addition, on-treatment samples from further therapy cycles were collected during chemotherapy (n = 58) and ICI therapy (n = 11). Serum PD-L1 levels were determined using ELISA. High baseline sPD-L1 levels were associated with worse ECOG status (p = 0.007) and shorter overall survival for both chemotherapy- and ICI-treated patients (p = 0.002 and p = 0.040, respectively). Multivariate analysis revealed high baseline sPD-L1 level as an independent predictor of poor survival for platinum-treated patients (p = 0.002). A correlation analysis between serum concentrations of PD-L1 and matrix metalloprotease-7 (MMP-7)—a protease which was recently found to cleave PD-L1—revealed a positive correlation (p = 0.001). No significant sPD-L1 changes were detected during chemotherapy, while in contrast we found a strong, 25-fold increase in sPD-L1 levels during atezolizumab treatment. In conclusion, our work demonstrates that pretreatment sPD-L1 levels are associated with a poor prognosis of BC patients undergoing platinum and ICI therapy. Future research should prospectively address the value of sPD-L1 in predicting treatment response.

Objective: Administration of targeted therapies provides a promising treatment strategy for urachal adenocarcinoma (UrC) or primary bladder adenocarcinoma (PBAC); however, the selection of appropriate drugs remains difficult. Here, we aimed to establish a routine compatible methodological pipeline for the identification of the most important therapeutic targets and potentially effective drugs for UrC and PBAC.Methods: Next‐generation sequencing, using a 161 cancer driver gene panel, was performed on 41 UrC and 13 PBAC samples. Clinically relevant alterations were filtered, and therapeutic interpretation was performed by in silico evaluation of drug‐gene interactions.Results: After data processing, 45/54 samples passed the quality control. Sequencing analysis revealed 191 pathogenic mutations in 68 genes. The most frequent gain‐of‐function mutations in UrC were found in KRAS (33%), and MYC (15%), while in PBAC KRAS (25%), MYC (25%), FLT3 (17%) and TERT (17%) were recurrently affected. The most frequently affected pathways were the cell cycle regulation, and the DNA damage control pathway. Actionable mutations with at least one available approved drug were identified in 31/33 (94%) UrC and 8/12 (67%) PBAC patients.Conclusions: In this study, we developed a data‐processing pipeline for the detection and therapeutic interpretation of genetic alterations in two rare cancers. Our analyses revealed actionable mutations in a high rate of cases, suggesting that this approach is a potentially feasible strategy for both UrC and PBAC treatments.

Urachal cancer (UrC) is a rare disease with limited availability of representative incidence and clinical data. Although, the prevalence is accounting for less than 1% of bladder tumors, the 5-year survival rate is around only 50% for patients with resectable tumors, and even worse for patients with metastatic disease. Due to the lack of comprehensive prospective studies, our current knowledge of UrC is still limited. The present study aimed to summarize the available registry-based studies with unselected UrC patients to evaluate its incidence and clinicopathological characteristics. We conducted a systematic literature search of registry-based UrC publications on the 15th of May 2023 in 5 databases, which identified 4,748 publications. After duplicate removal and selection by 2 independent investigators, 6 publications proved to be appropriate for the final meta-analysis. Estimated incidence and clinicopathological parameters were extracted. Estimated incidence ranged between 0.022 and 0.060/ 100.000 person-years, with the highest occurrence in Japan and the lowest in Canada, while the random effect model calculated an overall incidence rate of 0.04 (95%CI: 0.03-0.05) 100.000 person-years. The median age at first diagnosis was 60 years (range: 58-64). The female to male ratio was 2:3. Lymph node or distant metastases were present in 9% and 14% of patients. The predominant tumour type was adenocarcinoma (86%) followed by urothelial carcinoma (12%) and squamous cell carcinoma (2%). The 5-year survival rate was 51.0% with 95%CI: 45.2-57.4. Our study provides an up-to-date comparison of estimated incidence rates between 6 countries of 3 continents based on rigorously selected registry-based studies. The results suggest low incidence rates for UrC with considerable geographic differences. The present meta-analysis provides unbiased registry-based data on the incidence, clinicopathological parameters and survival of UrC.

Objective: To investigate the expression patterns of Nectin‐4, the target molecule of the antibody‐drug conjugate enfortumab vedotin (EV), in relation to histological and molecular subtypes of urothelial bladder cancer (UBC). Patients and Methods: We assessed the protein expression patterns of Nectin‐4 in a spatially organised tissue microarray containing 1386 tissue cores from 314 consecutive patients with UBC who underwent radical cystectomy (2005–2018). Results were correlated with clinicopathological and follow‐up data, as well as with different spatial locations (tumour central vs tumour‐normal interface and primary tumour vs lymph node [LN] metastases). Additionally, we correlated Nectin‐4 expression levels with histological and molecular subtypes. Finally, we assessed the value of Nectin‐4 expression for predicting the efficacy of platinum therapy in the peri‐operative setting. Results: Nectin‐4 expression was observed in 63% of primary tumours and 87% of LN metastases, with significantly higher levels in LNs. Of the histological subtypes, the micropapillary (58%) and pure urothelial histologies (30%) were associated with the highest Nectin‐4 positivity, while the sarcomatoid (17%), squamous (15%) and small/cell‐neuroendocrine (0%) subtypes exhibited the lowest. Nectin‐4 immunopositivity rates were significantly higher in luminal (urothelial‐like [42%] and genomically unstable [34%] Lund subtypes) compared to the basal (5%) or mesenchymal (0%) molecular subtypes. Higher Nectin‐4 expression levels were associated with lower tumour stage but showed no association with overall survival. Finally, patients with low Nectin‐4 expression tended to derive more benefit from platinum‐based chemotherapy in both adjuvant and neoadjuvant settings ( P < 0.001, P = 0.067). Conclusion: Our results revealed a low spatial heterogeneity of Nectin‐4 expression within the primary tumour. In contrast, differential Nectin‐4 expression was found in the context of histological and molecular subtypes. Nectin‐4‐expressing tumours may show varying sensitivity to both EV and platinum‐based chemotherapy.

Objective: Although targeted approaches have become available in second‐ and third‐line settings, platinum‐based chemotherapy remains the standard first‐line treatment for advanced muscle‐invasive bladder cancer (MIBC). Therefore, the prediction of platinum resistance is of utmost clinical importance.Methods: In this study, we established a routine compatible method for the molecular classification of MIBC samples according to various classification systems and applied this method to evaluate the impact of subtypes on survival after adjuvant chemotherapy. This retrospective study included 191 patients with advanced MIBC (pT≥3 or pN+) who underwent radical cystectomy, with or without adjuvant chemotherapy. A 48‐gene panel and classifier rule set were established to determine molecular subtypes according to TCGA, MDA, LundTax, and Consensus classifications. Additionally, 12 single platinum‐predictive candidate genes were assessed. The results were correlated with patients' clinicopathological and follow‐up data and were validated using independent data sets.Results: Our final evaluation of 159 patients demonstrated better survival in the luminal groups for those who received chemotherapy compared with those who did not. In contrast, no such differences were observed in basal subtypes. The use of chemotherapy was associated with better survival in patients with high APOBEC3G expression (p < 0.002). This association was confirmed using an independent data set of patients who received neoadjuvant platinum therapy.Conclusions: The proposed method robustly replicates the most commonly used transcriptome‐based subtype classifications from paraffin‐embedded tissue samples. The luminal, but not basal, molecular subtypes had the greatest benefit from adjuvant platinum therapy. We identified and validated APOBEC3G as a novel predictive marker for platinum‐treated patients.

Chemotherapy resistance is a main cause of therapeutic failure and death in bladder cancer. With the approval of immune checkpoint inhibitors, prediction of platinum treatment became of great clinical importance. Matrix metalloproteinase-7 (MMP-7) was shown to be involved in cisplatin resistance. Therefore, tissue and circulating MMP-7 levels were evaluated in 124 bladder cancer patients who received postoperative platinum-based chemotherapy. Tissue MMP-7 levels were analyzed by immunohistochemistry in 72 formalin-fixed, paraffin-embedded chemo-naïve tumor samples, while MMP-7 serum concentrations were determined in 132 serum samples of an independent cohort of 52 patients. MMP-7 tissue and serum levels were correlated with clinicopathological and follow-up data. MMP-7 gene expression was determined by RT-qPCR in 20 urothelial cancer cell lines and two non-malignant urothelial cell lines. MMP-7 was overexpressed in RT-112 and T-24 cells by stable transfection, to assess its functional involvement in platinum sensitivity. High MMP-7 tissue expression and pretreatment serum concentrations were independently associated with poor overall survival (tissue HR = 2.296, 95%CI = 1.235–4.268 and p = 0.009; serum HR = 2.743, 95%CI = 1.258–5.984 and p = 0.011). Therefore, MMP-7 tissue and serum analysis may help to optimize therapeutic decisions. Stable overexpression in RT-112 and T-24 cells did not affect platinum sensitivity.