PD-L1 expression in bladder cancer and metastasis and its influence on oncologic outcome after cystectomy

PD-L1 expression and its correlation with tumor biomarkers in Chinese urothelial bladder cancer

Data on prevalence of programmed death ligand-1 (PD-L1) expression and its correlation with tumor biomarkers in Chinese patients with muscle-invasive urothelial bladder cancer (MIUBC) are scarce. We investigated the prevalence of PD-L1 expression, PD-L1 expression in tumor cells (TC) and immune cells (IC), and its correlation with tumor biomarkers (CD8+ T cells and tumor mutation burden [TMB]) in Chinese patients with newly diagnosed MIUBC (NCT03433924). Of 248 patients enrolled, 229 with PD-L1 data available were analysed. High PD-L1 expression (≥ 25% of TC or IC with PD-L1 expression) was observed in 120 (52.4%) patients. 59 cases showed positive staining in ≥ 25% of TC, and 82 cases had positive staining in ≥ 25% of IC. High expression of CD8+ T cell and TMB (> 10 mutations/megabase) was observed in 44.5% and 54.1% patients, respectively. A positive correlation was observed between percentage of TC with membrane PD-L1 positivity and CD8+ T cells (0.34; P < 0.001) and between IC with membrane PD-L1 positivity and CD8+ T cells (0.44; P < 0.001). There is high prevalence of PD-L1 expression in Chinese patients with MIUBC, suggesting that a sizable subset of patients could benefit from immunotherapy. The correlation of PD-L1 expression with tumor biomarkers provide clues for mechanisms underlying the effects of biomarkers for predicting efficacy.

Programmed Cell Death Ligand 1 (PD-L1) Immunohistochemical Expression in Advanced Urothelial Bladder Carcinoma: An Updated Review with Clinical and Pathological Implications

The management of advanced bladder carcinoma involves a multidisciplinary approach, but the prognosis remains poor for many patients. The immune system plays a crucial role in this disease, influencing both tumor development and response to treatment, and exploiting the immune system against the tumor can be a valuable strategy to destroy neoplastic cells. This is the biological principle underlying Bacillus Calmette-Guérin (BCG) use and, more recently, immune checkpoint inhibitors (ICIs), like PD-1 (programmed death-1)/PD-L1 (programmed death-ligand 1) inhibitors. In fact, one of the best studied immune checkpoints is represented by the PD-1/PD-L1 axis, which is a well-known immune escape system adopted by neoplastic bladder cells. PD-L1 expression has been associated with a higher pathologic stage and has shown prognostic value in bladder carcinoma. Interestingly, high-grade bladder cancers tend to express higher levels of PD-1 and PD-L1, suggesting a potential role of such an axis in mediating disease progression. Immunotherapy with PD-1 and PD-L1 inhibitors has therefore emerged as a valuable treatment option and has shown efficacy in advanced bladder cancer patients, with high PD-L1 expression levels associated with better treatment responses. Our review aims to provide a comprehensive overview of the role of PD-L1 in advanced bladder cancer, focusing on its implications for treatment decisions and the prediction of treatment response. Overall, our work aims to contribute to the understanding of PD-L1 as a predictive biomarker and highlight its role in shaping therapeutic approaches for advanced bladder cancer.

Evaluation of the Expression of Programmed Death-Ligand 1 and Its Role in Differentiating Low-Grade and High-Grade Urothelial Carcinoma

BACKGROUND

Urothelial carcinoma (UC) is a common malignancy, predominantly affecting males. Many tumor cells use the interaction between programmed death-ligand 1 (PD-L1) and programmed death receptor (PD-1) to inactivate T-cells in the microenvironment and evade host immune response. Our study aims to evaluate the expression of PD-L1 in UC and correlate its expression with histomorphological parameters.

MATERIALS AND METHODS

After obtaining approval from the Institute Ethics Committee, we conducted a prospective observational study on transurethral resection of urinary bladder tumor (TURBT) and cystectomy specimens histopathologically diagnosed as UC between 2022 and 2023, comprising 50 cases. All standard protocol was followed and immunohistochemistry (IHC) was done using PD-L1 with rabbit anti-human PD-L1 monoclonal antibody (Clone: IHC411; Biogenics Inc., San Francisco, CA, USA).  Results: Among the 50 cases of UC, the majority were papillary type (35 cases), high grade (28 cases), and non-muscle invasive (30 cases). Among the cases studied, 15 of them showed PD-L1 positivity; 55% of the cases of muscle-invasive bladder cancer were found to be positive for PD-L1 out of which the results were statistically significant.

CONCLUSION

PD-L1 expression by IHC staining can differentiate between muscle-invasive and non-muscle-invasive UC cases. This observation allows for further exploring the potential role of immune checkpoint inhibitors in adjuvant and neoadjuvant therapy, especially in muscle-invasive cases of UC.

The clinical significance of PD-1 expression in patients with bladder cancer without lymph node metastasis: a comparative study with drained lymph nodes and tumor tissues

OBJECTIVE

In light of the increasing importance of immunotherapy in bladder cancer treatment, this study is aim to investigate the expression and clinical significance of programmed cell surface death-1 (PD-1) in bladder cancer patients without lymph node metastasis, and to compare and analyze the difference of PD-1 in draining lymph nodes and tumor tissues.

METHODS

The expression of PD-1 on T cells and the proportion of positive PD-1 + T cells of IFN-γ and CD105a were detected by flow cytometry, and the correlation between PD-1 expression and clinical parameters was analyzed.

RESULTS

The percentage of PD-1 positive cells in drainage lymph nodes was higher than that in tumor tissues (P < 0.001). PD-1 positive cells accounted for the highest proportion in CD3 + T cells. The proportion of IFN-γ-positive PD-1 + T cells in draining lymph nodes was significantly higher than that in tumor tissues (P < 0.001), while there was no significant difference in CD105a positive PD-1 + T cells between tumor tissues and draining lymph nodes. Pathological grade, tumor size and stage were positively correlated with PD-1 expression level in the lymph nodes.

CONCLUSION

The high expression of PD-1 in patients with bladder cancer without lymph node metastasis, especially in draining lymph nodes, suggests that PD-1 may play a key role in the regulation of tumor immune microenvironment. The correlation between PD-1 and clinical parameters indicates its potential prognostic value. These findings provide important clinical implications for PD-1 targeted therapy, but further prospective studies are needed to determine the application value of PD-1 in therapeutic strategies.

Integrating the PD-L1 Prognostic Biomarker in Non-Muscle Invasive Bladder Cancer in Clinical Practice-A Comprehensive Review on State-of-the-Art Advances and Critical Issues

Bladder cancer (BC) is one of the most prevalent cancers worldwide. Non-muscle invasive bladder cancer (NMIBC), comprising the majority of initial BC presentations, requires accurate risk stratification for optimal management. This review explores the evolving role of programmed cell death ligand 1 (PD-L1) as a prognostic biomarker in NMIBC, with a particular focus on its implications in the context of Bacillus Calmette-Guérin (BCG) immunotherapy. The literature suggests a potential association between elevated PD-L1 status and adverse outcomes, resistance to BCG treatment, and disease progression. However, conflicting findings and methodological issues highlight the heterogeneity of PD-L1 assessment in NMIBC, probably due to the complex biological mechanisms that regulate the interaction between PD-L1 and the tumor microenvironment. The identification of PD-L1 as a prognostic biomarker provides ground for tailored therapeutic interventions, including immune checkpoint inhibitors (ICIs). Nevertheless, challenges such as intratumoral heterogeneity and technical issues underscore the need for standardized protocols and larger, homogeneous trials. This review contributes to the ongoing debate on the personalized management of NMIBC patients, focusing on the advances and perspectives of incorporating PD-L1 as a biomarker in this setting.

The Relationship Between PD-1(rs2227981) and PD-L1(rs2890658) Polymorphisms and Urothelial Cell Carcinoma

Background Urothelial cell carcinoma, which is believed to develop from the urothelium (transitional epithelium), is the most common aggressive tumor and accounts for the ten most prevalent cancers in the world. The risk factors for urothelial cell carcinoma are aging, smoking, gender, and genetic alternations. Programmed cell death1 (PD-1) has been widely described as a negative regulator of T-cells by sending inhibitory signals to the T-cell. Through PD-1 binding with PD-L1 (ligand for PD-1), an inhibitory signal is propagated to the T cell. The polymorphisms of PD-1 and PD-L1 lead to an efficient T-cell response and affect an anti-tumor reaction. The polymorphisms of PD-1 and PD-L1 could also affect the carcinogenesis of human cancer, including urothelial cell carcinoma. Therefore, in this study, we evaluated the relation between PD-1(rs2227981) and PD-L1(rs2890658) polymorphisms and the carcinogenesis of urothelial cell carcinoma. Materials and methods This study was conducted using 211 healthy controls and 256 cases of urothelial cell carcinoma among the Japanese population. The DNA samples were extracted from the peripheral white blood cells of each subject. The genotype was detected by using the Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) method. Results C/T (Adjusted OR 1.55, 95% CI:1.02-2.35) and C/T+T/T (OR 1.46, 95% CI:1.01-2.12) genotypes of PD-1 rs2227981 were significant and risk factors for urothelial cancer. Male with A/A genotype in PD-L1 and CT genotype in PD-1 has a significant higher risk factor compared with other genotypes (Adjusted OR 1.83, 95% CI:1.05-3.21). Conclusions and discussion We found that C/T(PD-1) and "A/A (PD-L1) and C/T(PD-1)" were predominant in urothelial cell carcinoma cases. This indicates that C/T(PD-1) and "A/A (PD-L1) and C/T(PD-1)" genotypes could increase susceptibility to urothelial cell carcinoma. However, since our findings indicated that the effects of PD-1 and PD-L1 polymorphisms included discrepancies, additional research will be needed to evaluate the relationship between human cancer and PD-1 and PD-L1 polymorphisms. This is the first study that seeks to find the relation between PD-1(rs2227981) and PD-L1(rs2890658) polymorphisms concerning urothelial cell carcinoma among the Japanese population.

Programmed Cell Death-Ligand-1 expression in Bladder Schistosomal Squamous Cell Carcinoma – There’s room for Immune Checkpoint Blockage?

Schistosoma haematobium, the causative agent of urogenital schistosomiasis, is a carcinogen type 1 since 1994. It is strongly associated with bladder squamous-cell carcinoma in endemic regions, where it accounts for 53-69% of bladder-carcinoma cases. This histological subtype is associated with chronic inflammation being more aggressive and resistant to conventional chemo and radiotherapy. Immune-Checkpoint-Blockage (ICB) therapies targeting the Programmed-Cell-Death-Protein-1(PD-1)/Programmed-Cell-Death-Ligand-1(PD-L1) axis showed considerable success in treating advanced bladder urothelial carcinoma. PD-L1 is induced by inflammatory stimuli and expressed in immune and tumor cells. The binding of PD-L1 with PD-1 modulates immune response leading to T-cell exhaustion. PD-L1 presents in several isoforms and its expression is dynamic and can serve as a companion marker for patients’ eligibility, allowing the identification of positive tumors that are more likely to respond to ICB therapy. The high PD-L1 expression in bladder-urothelial-carcinoma and squamous-cell carcinoma may affect further ICB-therapy application and outcomes. In general, divergent histologies are ineligible for therapy. These treatments are expensive and prone to auto-immune side effects and resistance. Thus, biomarkers capable of predicting therapy response are needed. Also, the PD-L1 expression assessment still needs refinement. Studies focused on squamous cell differentiation associated with S. haematobium remain scarce. Furthermore, in low and middle-income-regions, where schistosomiasis is endemic, SCC biomarkers are needed. This mini-review provides an overview of the current literature regarding PD-L1 expression in bladder-squamous-cell-carcinoma and schistosomiasis. It aims to pinpoint future directions, controversies, challenges, and the importance of PD-L1 as a biomarker for diagnosis, disease aggressiveness, and ICB-therapy prognosis in bladder-schistosomal-squamous-cell carcinoma.

Multicomponent siRNA/miRNA-loaded modified mesoporous silica nanoparticles targeted bladder cancer for a highly effective combination therapy

Bladder cancer is one of the concerning urological malignant diseases in the world, which has a clinical need for effective targeted therapy. The development of nanotechnology-based gene delivery to bladder tumor sites is an effective strategy for targeted cancer therapy with low/no toxicity. With this view, in the present work, the mesoporous silica nanoparticles (MSNs) modified with c(RGDfK)-PLGA-PEG [c(RGDfK)-MSN NPs] were constructed for co-delivery of miR-34a and siPD-L1 within bladder cancer cells and tissues. Our findings showed that miR-34a is downregulated while PD-L1 is up-regulated in cell lines and animal studies. This nano-carrier is biocompatible in the serum environment and effectively protects miR-34a and siPD-L1 against serum degradation. However, we showed that c(RGDfK)-MSN NPs could simultaneously downregulate PD-L1 expression and up-regulate miR-34a in the T24 cells and T24 mice model and enhance anti-tumor effects both in vivo and in vitro. In conclusion, these findings presented new suggestions for improving targeted therapeutic strategies with specified molecular objectives for bladder cancer treatment.

Evaluation of PD-L1 and B7-H3 expression as a predictor of response to adjuvant chemotherapy in bladder cancer

Introduction and objectives

PD-L1 and B7-H3 have been found to be overexpressed in urothelial carcinoma (UC) of the urinary bladder. Recent studies have also demonstrated that B7-H3 and PD-L1 can promote resistance to platinum-based drugs but the predictive value of B7-H3 expression in patients treated with platinum-based chemotherapy is unknown. This study aims to investigate the association of PD-L1 and B7-H3 tumor expression with oncological outcomes in patients who underwent radical cystectomy (RC) and received subsequent adjuvant chemotherapy.

Materials and methods

Immunohistochemistry was performed on paraffin-embedded sections from bladder and lymph node specimens of 81 patients who had RC for bladder cancer. PD-L1 and B7-H3 expression on tumor cells was assessed by immunohistochemistry in both primary tumors and lymph node specimens. Association with clinicopathologic outcomes was determined using Fisher's exact test and postoperative survival using Kaplan–Meier survival curves and Cox regression model.

Results

B7-H3 expression in cystectomy specimens was more common than PD-L1 expression (72.8% vs. 35.8%). For both markers, no association was found with pathologic tumor stage, lymph node (LN) status, and histological subtype. Similar findings were observed for double-positive tumors (PD-L1⁺B7-H3⁺). Concordance between the primary tumor and patient-matched lymph nodes was found in 76.2% and 54.1% of patients for PD-L1 and B7-H3, respectively. PD-L1 tumor expression was not associated with oncologic outcomes. However, B7-H3 expression was associated with recurrence-free survival (HR: 2.38, 95% CI 1.06–5.31, p = 0.035) and cancer-specific survival (HR: 2.67, 95% CI 1.18–6.04, p = 0.019).

Conclusions

In our single institutional study, B7-H3 is highly expressed in patients with UC treated with adjuvant chemotherapy and it was associated with decreased recurrence-free survival and cancer-specific survival. Pending further validation in larger cohorts, B7-H3 expression may function as a predictor of response to adjuvant chemotherapy and thus be useful in patient and regimen selection.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12894-022-01044-1.

Tumor-Associated Macrophages in Bladder Cancer: Biological Role, Impact on Therapeutic Response and Perspectives for Immunotherapy

Tumor-associated macrophages (TAMs) are one of the most abundant infiltrating immune cells of solid tumors. Despite their possible dual role, i.e., pro- or anti-tumoral, there is considerable evidence showing that the accumulation of TAMs promotes tumor progression rather than slowing it. Several strategies are being developed and clinically tested to target these cells. Bladder cancer (BCa) is one of the most common cancers, and despite heavy treatments, including immune checkpoint inhibitors (ICIs), the overall patient survival for advanced BCa is still poor. TAMs are present in bladder tumors and play a significant role in BCa development. However, few investigations have analyzed the effect of targeting TAMs in BCa. In this review, we focus on the importance of TAMs in a cancerous bladder, their association with patient outcome and treatment efficiency as well as on how current BCa treatments impact these cells. We also report different strategies used in other cancer types to develop new immunotherapeutic strategies with the aim of improving BCa management through TAMs targeting.

Prognostic Role of Programmed Death Ligand-1 on Tumor-Infiltrating Immune Cells in "High-Risk" Patients Following Radical Cystectomy: A Retrospective Cohort Study

Purpose

The aim of this study is to investigate the prognostic role of programmed death ligand-1 (PD-L1) on tumor-infiltrating immune cells (TIICs) in patients after radical cystectomy (RC) for bladder cancer (BCa).

Materials and Methods

We retrospectively reviewed 92 “high-risk” (≥pT3a and/or pN+) patients who underwent RC for BCa, without adjuvant chemotherapy (AC), between April 2014 and December 2019. PD-L1 on TIICs was measured only using the VENTANA (SP-142) immunohistochemistry assay. Patients were categorized into three groups based to the percentage of the tumor area covered by PD-L1 on TIICs: IC0 (<1%), IC1 (≥1% and <5%), and IC2/3 (≥5%). Positive PD-L1 was defined as IC2/3 (≥5%). Kaplan–Meier survival analysis was used to illustrate recurrence-free survival (RFS), and Cox proportional hazard models were used to identify predictive factors of tumor recurrence.

Results

Within the cohort, the proportions of PD-L1 IC0, IC1, and IC2/3 were 21.7%, 23.9%, and 54.4%, respectively. At follow-up (mean 31.3 months), tumor recurrence was identified in 49 patients (53.3%). Using multivariable analysis, tumor stage (pT4; P=0.005), positive lymph nodes (P=0.021), and positive PD-L1 on TIICs (P=0.010) were independent predictors of tumor recurrence. The 2- and 3-year RFS rates were 67.7% and 64.2% in negative PD-L1 on TIICs, while 27.8% and 22.3% in positive PD-L1 on TIICs, respectively.

Conclusions

Positive PD-L1 on TIICs was significantly associated with poorer RFS in “high-risk” patients after RC without AC. Our results support the use of adjuvant immunotherapy in “high-risk” patients with positive PD-L1 on TIICs after RC.

PD-L1 expression in bladder cancer: Which scoring algorithm in what tissue?

INTRODUCTION

For cisplatin-ineligible patients, approval of first-line immune-checkpoint inhibitor therapy relies on the programmed death ligand 1 (PD-L1) expression assay employed, namely, the combined positive score (CPS) or immune cell (IC) score. This study compares PD-L1 diagnostic scores and positivity in primary and matched metastatic bladder cancer tissue.

METHODS

A total of 108 patients undergoing radical cystectomy for urothelial bladder cancer and lymphatic spread (pN+) were included. PD-L1 expression was compared by immunohistochemistry (IHC) between the primary bladder tumor and associated lymph node metastases using Ventana SP263 anti-PD-L1 antibody. In a subset of cases further IHC was performed with Ventana SP142 and Dako 22C3 antibodies. Second, the PD-L1 scoring algorithms for the CPS and IC score were compared. Correlation of PD-L1 positivity with clinical parameters and tumor stage was assessed. Intra- and intertissue analyses were performed with Pearson's chi square test, McNemar test and Spearman correlation employing IBM SPSS 25.

RESULTS

PD-L1 expression did not correlate with clinicopathological parameters. The CPS (43.5% vs. 35.6%; P=0.006) and the IC score (28.7% vs. 21.2%; P=0.002) yielded PD-L1 positivity significantly more often in primary BC than in matched lymph node metastasis. Both the CPS (r=0.775; P<0.001) and the IC score (r=0.711; P<0.001) correlated between primary and metastatic bladder cancer tissue. Employing CPS vs. IC led to significantly more PD-L1-positive classified cases in primary BC (CPS vs. IC; 43.5% vs. 28.7%; P<0.001) and lymph node metastasis (CPS vs. IC; 35.6% vs. 21.2%, P<0.001).

CONCLUSION

Compared to lymph node analysis, bladder tissue yields more PD-L1 positivity assessed with the CPS and IC scores. This is particularly evident when employing the CPS. The findings highlight that employing both PD-L1 assays may maximize eligibility for first-line checkpoint-inhibitors to treat bladder cancer patients unfit for cisplatin-based chemotherapy.

High PD-L1 expression on immune cells, but not on tumor cells, is a favorable prognostic factor in urothelial carcinoma

Aims: To explore the prognostic value of high PD-L1 expression on tumor cells (TC) and tumor-infiltrating immune cells (TIIC) in urothelial carcinoma (UC). Patients & methods: 162 UC specimens were evaluated for PD-L1 expression on TIIC and TC with the SP263 assay. High PD-L1 expression was defined as ≥25% staining. Results: High PD-L1 expression on TC in UC patients with stage T1-4 disease was associated with poor overall survival. However, high PD-L1 expression on TIIC in UC patients with stage T1-4 disease revealed favorable disease-free and overall survival; more significant differences were observed in patients with stages T2-4. Multivariate analysis revealed that high PD-L1 expression on TIIC was an independent prognostic predictor for better disease-free and overall survival. Conclusion: High PD-L1 expression on TIIC, but not on TC, is a favorable prognostic factor in UC.

High Serum PD-L1 Levels Are Associated with Poor Survival in Urothelial Cancer Patients Treated with Chemotherapy and Immune Checkpoint Inhibitor Therapy

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.

PD-L1 Expression in Muscle Invasive Urothelial Carcinomas as Assessed via Immunohistochemistry: Correlations with Specific Clinical and Pathological Features, with Emphasis on Prognosis after Radical Cystectomy

In the present study, we analyzed Programmed Death Ligand-1 (PD-L1) expression in radical cystectomy (RC) specimens from patients with muscle-invasive urothelial carcinoma (UC), in order to assess any correlations with specific clinicopathological features and its potential prognostic value. A multi-institutional study was performed within the departments of urology and pathology at the Mureș County Hospital, Romania, and Centre Hospitalier Lyon Sud, France. Sixty-nine patients with MIBC were included, for whom tumor histology (conventional versus histological variant/differentiation), tumor extension (T), lymph node involvement (N), and distant metastases (M) were recorded. PD-L1 immunostaining was performed using the 22C3 clone and was interpreted using the combined positive score (CPS) as recommended (Dako Agilent, Santa Clara, CA, USA). Positive PD-L1 immunostaining was more prevalent among UCs with squamous differentiation compared to conventional UCs and trended towards an improved OS (p = 0.366). We found the T stage to be a risk factor for poor survival in PD-L1-positive patients (HR 2.9, p = 0.021), along with the N stage in PD-L1-negative patients (HR 1.98, p = 0.007). No other clinicopathological factor was found to be significantly associated with PD-L1 positivity. Thus, we confirm the need for PD-L1 immunostaining prior to initiating immune checkpoint inhibitor therapy for a more accurate assessment of the patients’ chances of responding to treatment.

p53 Expression, Programmed Death Ligand 1, and Risk Factors in Urinary Tract Small Cell Carcinoma

Introduction: Small cell carcinoma of the urinary tract (SCCUT) is a rare finding with poor clinical course. This study sheds light on the molecular subtype and identifies risk factors in patients diagnosed with SCCUT.

Methods: Immunohistochemical expression of immunotherapy target programmed death ligand 1 (PD-L1) and luminal (GATA3), basal (p63), and p53 markers are assessed in patients diagnosed with SCCUT. Univariate analysis identified risk factors. Overall survival (OS) is computed using the Kaplan–Meier method.

Results: Tissue was available for 70.2% (33/47). All showed a high PD-L1 expression phenotype. p53 is seen in 93.9% (31/33), mostly as overexpression, GATA3 in 45.5% (15/33), and p63 in 57.6% (19/33). For the entire cohort (n = 47), 1-year survival was 59.6%, and the median OS was 17 months. Univariate analysis shows that chemotherapy [hazard ratio (HR) = 0.29, 95% confidence interval (CI) = 0.14–0.61, p = 0.001], radical surgery (HR = 0.37, 95% CI = 0.18–0.76, p = 0.007), and diagnosis of non-pure SCCUT (HR = 0.44, 95% CI = 0.22–0.86, p = 0.02) are favorable prognostic features. Metastasis had negative associations with survival (HR = 2.1, 95% CI = 1.1–4.2, p = 0.03).

Conclusions: In this series, pure and mixed SCCUT are characterized by p53 overexpression and a high PD-L1 phenotype. Histology of non-pure SCCUT is a positive prognosticator, and radical cystectomy or chemotherapy can improve OS. These findings demonstrate that SCCUT may be eligible for PD-L1 immunotherapy.

Prognostic value of PD-L1 combined positive score in patients with upper tract urothelial carcinoma

PURPOSE

Upper tract urothelial carcinoma (UTUC) is relatively rare in Western countries. The impact of programmed death-ligand 1 (PD-L1) expression on UTUC remains unclear because previous studies have focused on bladder UC. We investigated the association of PD-L1 expression with clinicopathological features and prognosis in patients with UTUC.

METHODS

We retrospectively reviewed the patients with UTUC that we treated at our institute from 2013 to 2018. In total, 105 patients with UTUC undergoing radical nephroureterectomy were analyzed to evaluate the PD-L1 expression on representative whole-tissue sections using the Combined Positive Score (CPS; Dako 22C3 pharmDx assay). A PD-L1 CPS ≥ 10 was considered positive.

RESULTS

Among the 105 UTUC cases, 17.1% exhibited positive PD-L1 expression. A CPS ≥ 10 was significantly associated with higher tumor stage (≥ T2, p = 0.034) and lymph node invasion at diagnosis (p = 0.021). A multivariable analysis indicated that a CPS ≥ 10 was an independent prognostic predictor of shorter cancer-specific survival (hazard ratio [HR] = 4.59, 95% confidence interval [CI] = 1.66 - 12.7, p = 0.003) and overall survival (HR = 2.51, 95% CI = 1.19 - 5.27, p = 0.015).

CONCLUSIONS

A PD-L1 CPS ≥ 10 in UTUC was associated with adverse pathological features and independently predicted worse cancer-specific and overall survival.

PD-L1 as a biomarker of response to immune-checkpoint inhibitors

Immune-checkpoint inhibitors targeting PD-1 or PD-L1 have already substantially improved the outcomes of patients with many types of cancer, although only 20-40% of patients derive benefit from these new therapies. PD-L1, quantified using immunohistochemistry assays, is currently the most widely validated, used and accepted biomarker to guide the selection of patients to receive anti-PD-1 or anti-PD-L1 antibodies. However, many challenges remain in the clinical use of these assays, including the necessity of using different companion diagnostic assays for specific agents, high levels of inter-assay variability in terms of both performance and cut-off points, and a lack of prospective comparisons of how PD-L1⁺ disease diagnosed using each assay relates to clinical outcomes. In this Review, we describe the current role of PD-L1 immunohistochemistry assays used to inform the selection of patients to receive anti-PD-1 or anti-PD-L1 antibodies, we discuss the various technical and clinical challenges associated with these assays, including regulatory issues, and we provide some perspective on how to optimize PD-L1 as a selection biomarker for the future treatment of patients with solid tumours.

Landscape of Immunotherapy in Genitourinary Malignancies

The past decade has witnessed a revolution in the development of immune checkpoint inhibitors for the treatment of multiple tumor types, including genitourinary cancers. Immune checkpoint inhibitors have notably improved the treatment outcomes of patients with metastatic renal cell carcinoma and metastatic urothelial carcinoma. In prostate cancer, the role of immunotherapy with checkpoint inhibitors is not yet established except for microsatellite instability high (MSI-H) tumors. Other immunotherapeutic approaches that have been explored in these malignancies include cytokines, vaccines, and cellular therapy. Ongoing studies are exploring the use of immunotherapy combinations as well as combination with chemotherapy and targeted therapy in these types of tumors. The use of immunotherapy beyond the metastatic setting is an active area of research. Moreover, there is great interest in biomarker development to predict response to immunotherapy and risk of toxicity. This book chapter is a comprehensive review of immunotherapeutic approaches, both approved and investigational, for the treatment of renal cell carcinoma, urothelial carcinoma, and prostate cancer.

Discordance of immunotherapy response predictive biomarkers between primary lesions and paired metastases in tumours: A systematic review and meta-analysis

Background

Several biomarkers predict the efficacy of immunotherapy, which is essential for selecting patients who would potentially benefit. Discordant status of these biomarkers between primary tumours and paired metastases has been increasingly revealed. We aimed to comprehensively summarize the incidence of this phenomenon.

Methods

Databases were searched to identify studies reporting primary-to-metastatic conversion of biomarkers, including programmed death ligand-1 (PD-L1), programmed cell death protein-1 (PD-1), PD-L2, tumour-infiltrating lymphocyte (TIL), tumour mutational burden (TMB), and microsatellite instability (MSI).

Findings

56 studies with 2739 patients were included. The pooled discordance rate of PD-L1 was 22%. The percentage of PD-L1 changed from positive to negative was 41%, whereas that from negative to positive was 16%. The discordance rate for PD-1 and PD-L2 was 26% and 22%, respectively. TIL level was found with a discordance rate of 39%, and changes from high to low (50%) occurred more than that from low to high (16%). No significant difference in TMB was observed between two sites in most studies. MSI status discordance was found in 6% patients, with a percentage of 9% from MSI-high to microsatellite instable (MSS) and 0% from MSS to MSI-high.

Interpretation

Our study demonstrates that PD-L1, PD-1, PD-L2, and TIL level had high frequency of discordance, while TMB and MSI status were less likely to change between primary tumours and paired metastases. Therefore, evaluating those frequently altered biomarkers of both primary and metastatic tumours is strongly recommended for precise clinical decision of immune checkpoint treatment.

Fund

The National Natural Science Foundation of China (81872152).

Future Strategies Involving Immune Checkpoint Inhibitors in Advanced Urothelial Carcinoma

OPINION STATEMENT

Immune checkpoint inhibitors have importantly improved the outcome of patients with urothelial carcinoma. Different immune checkpoint inhibitors are currently approved and used in first- and second-line setting. The multiple agents currently approved in these setting make the choice sometimes difficult for clinicians. Furthermore, only a minority of patients present drastic response and long-term benefit with current immunotherapy. In this review, we describe the current use of immunotherapy in urothelial carcinoma but we also highlight the new strategies of treatment involving immune checkpoint inhibitors; we describe the place of immunotherapy with chemotherapy, targeted agents, and anti-angiogenic agents, incorporating the recent results presented at ASCO 2020. This review explores also the different action mechanisms of immune checkpoint inhibitors and the molecular rational to evaluate these agents in other strategies, such as maintenance and salvage strategies. The new advances in biomarker development are also presented.

Neoadjuvant chemotherapy for upper tract urothelial carcinoma

Upper tract urothelial carcinoma (UTUC) is a very uncommon disease that occupies for <5% of all urothelial cancers. Radical nephroureterectomy (RNU) remains the standard-of-care for UTUC; however, when patients with locally advanced UTUC are treated with RNU only, the recurrence rate is high. Therefore, perioperative chemotherapy has been proposed given the high systemic recurrence rate. Moreover, there is growing evidence that neoadjuvant chemotherapy (NAC) plays an important role in the treatment of UTUC. Several studies and meta-analyses have reported the beneficial effect of NAC on survival outcomes and pathologic downstaging of patients with UTUC. However, the recommendation of NAC for UTUC is primarily based on level 1 evidence that demonstrated a beneficial effect on survival outcomes in patients with bladder cancer. The chemotherapy regimen for patients with UTUC is also based on that used for patients with bladder cancer. Nevertheless, the use of NAC for UTUC has some limitations, including the possibility of overtreatment. Therefore, selection criteria for NAC are needed, as are further trials to identify the most suitable patients and validate its use in daily clinical practice.

The Prevalence and Prognostic Role of PD-L1 in Upper Tract Urothelial Carcinoma Patients Underwent Radical Nephroureterectomy: A Systematic Review and Meta-Analysis

Background: Several studies investigating the role of PD-L1 in upper tract urothelial carcinoma (UTUC) patients after radical nephroureterectomy (RNU) to predict prognosis had been published and great controversy existed among them. We, therefore, in the meta-analysis, reported the association between PD-L1 and survival in UTUC patients who underwent RNU.

Methods: We searched the PubMed, Cochrane Library, EMBASE, and Web of Science by April 1, 2020. Hazard ratio (HR) and odds ratio (OR) were adopted to evaluate relationships between PD-L1 and survival outcomes, and tumor features, respectively. We formulated clinical questions and organized following the PICOS strategy.

Results: Eight retrospective studies incorporating 1406 patients were included. The pooled positive rate of PD-L1 in UTUC patients was 21.0% (95% CI = 13.0–30.0%, I² = 95.3%). Furthermore, higher PD-L1 in tumor tissues was related to shorter cancer-specific survival (CSS) in radically resected UTUC patients (HR = 1.63, 95% CI = 1.17–2.26, I² = 0.0%), but was not associated with overall survival (OS) (HR = 1.49, 95% CI = 0.76–2.91, I² = 74.9%). Subgroup analyses indicated associations between higher PD-L1 and shorter CSS in both Caucasus (HR = 1.72, 95% CI = 1.02–2.92, I² = 0.0%) and Asian (HR = 1.57, 95% CI = 1.03–2.39, I² = 23.1%) UTUC patients. Furthermore, PD-L1 was related to tumor grade of UTUC (High vs. Low, OR = 3.56, 95% CI = 1.82–6.97, P = 0.000) and invasive depth (pT3+pT4+pT2 vs. pT1+pTa/pTis, OR = 2.53, 95% CI = 1.07–5.96, P = 0.001). In the cumulative meta-analysis, results indicated that the 95% CIs narrowed as the pooled results gradually moved near the null.

Conclusions: PD-L1 overexpression was related to worse survival outcomes in UTUC patients after RNU. It may be useful to incorporate PD-L1 into prognostic tools to select appropriate treatment strategies for UTUC. PD-L1 can also be clinically used for survival anticipation, risk stratification, and patient counseling. However, the pooled findings should be considered tentative until ascertained by more researches.

Pathological roles of c-Met in bladder cancer: Association with cyclooxygenase-2, heme oxygenase-1, vascular endothelial growth factor-A and programmed death ligand 1

c-Met is a receptor tyrosine kinase that binds a specific ligand, namely hepatocyte growth factor (HGF). The HGF/c-Met system is important for malignant aggressiveness in various types of cancer, including bladder cancer (BC). However, although phosphorylation is the essential step required for biological activation of c-Met, pathological roles of phosphorylated c-Met at the clinical and molecular levels in patients with BC are not fully understood. In the present study, the expression levels of c-Met and the phosphorylation of two of its tyrosine residues (pY1234/pY1235 and pY1349) were immunohistochemically examined in 185 BC tissues. The associations between these expression levels and cancer cell invasion, metastasis, and cyclooxygenase-2 (COX-2), heme oxygenase-1 (HO-1), VEGF-A and programmed death ligand 1 (PD-L1) levels were investigated. c-Met was associated with muscle invasion (P=0.021), as well as the expression levels of HO-1 (P=0.028) and PD-L1 (P<0.001), whereas pY1349 c-Met was associated with muscle invasion (P=0.003), metastasis (P=0.025), and COX-2 (P=0.017), HO-1 (P=0.031) and PD-L1 (P=0.001) expression. By contrast, pY1234/1235 c-Met was associated with muscle invasion and metastasis (P=0.006 and P=0.012, respectively), but not with the panel of cancer-associated molecules. Furthermore, COX-2 and PD-L1 expression were associated with muscle invasion and metastasis, respectively (P=0.045 and P=0.036, respectively). Hence, c-Met serves important roles in muscle invasion by regulating HO-1 and PD-L1, whereas its phosphorylation at Y1349 is associated with muscle invasion and metastasis via the regulation of COX-2, HO-1 and PD-L1 in patients with BC. Furthermore, phosphorylation at Y1234/1235 may lead to muscle invasion and metastasis via alternate mechanisms associated with c-Met and pY1349 c-Met.

Relapse-Free Survival and PD-L1 Expression in First High- and Low-Grade Relapsed Luminal, Basal and Double-Negative P53-Mutant Non-Muscular Invasive Bladder Cancer Depending on Previous Chemo- and Immunotherapy

The goal of this study was to assess how PD-L1 expression in tissue specimens of patients with main molecular subtypes of NMIBC (luminal, basal and double-negative p53-mutant) associates with relapsed-free survival in dependence on the tumor grade and prior treatment of primary bladder cancer. PD-L1 expressions on the membrane of neoplastic and CD8+ immune cells were assessed in tumor specimens (n = 240) of primary and relapsed luminal, basal and double-negative p53-mutant NMIBC. Association between relapse-free survival and PD-L1 expression was estimated for high- and low-grade relapsed NMIBC according to previous treatment and their molecular profile, using the Kaplan-Meier method, and assessed by using the log-rank test. Potential confounders were adjusted by Cox regression models. In a group of patients who underwent only TUR without intravesical therapy, there were significant differences in relapse time between high- and low-grade tumors in basal and luminal molecular subtypes; for basal relapsed carcinoma, RFS was shorter in cases where tumors were less malignant. Both intravesical mitomycin and Bacillus Calmette-Guerin (BCG) therapy significantly extended the time of recurrence of low-grade luminal and basal bladder malignancies with no intergroup differences in double-negative NMIBC. PD-L1 expression status was associated with RFS for luminal relapsed NMIBCs in the group without previous frontline intervention, and with RFS in the group of patients with luminal relapsed bladder cancer previously utilized BCG. Obtained results may be considered as a promising approach for further clinical implementation.

PD-L1 Expression in Urothelial Carcinoma With Predominant or Pure Variant Histology: Concordance Among 3 Commonly Used and Commercially Available Antibodies

The introduction of immune checkpoint blockade (ICB) therapy has transformed the management of advanced bladder cancer (BC). Despite its limitations, PD-L1 immunohistochemistry may serve as a predictive biomarker of anti-PD-L1/PD1 therapy. While urothelial carcinoma (UC) patients with predominant or pure variant histology (UCV) account for up to one-third of advanced cases, to date, most ICB BC studies have excluded patients with such histologies. To assess the potential utility of ICB in patients with UCV, we analyzed PD-L1 expression in UCV and compared 3 commonly used and commercially available PD-L1 antibodies. Full sections from 84 UCV cases were stained with clones SP263, 22C3, and SP142, all of which are considered predictive assays to identify UC patients who are more likely to respond to anti-PD-1/PD-L1 inhibitors durvalumab, pembrolizumab, and atezolizumab, respectively. Expression on tumor cells (TC) and tumor-infiltrating immune cells (IC) was assessed. Staining extent and characteristics were evaluated, and concordance among the 3 clones was determined at various cutoff points as used in previous studies in BC. We found that PD-L1 was expressed in a significant percentage of UCV cases at different cutoff points (cutoff 1% TC: 37% to 54%, cutoff 5% TC: 23% to 37%), with the highest expression in UC with squamous differentiation. These figures are equal to or higher than those for classic/pure UC (4% to 30%). The results suggest that patients with UCV may benefit from anti-PD-1/PD-L1 therapy and argue against the exclusion of UC with predominant or pure variant histology from clinical ICB studies. The highest expression in both TC and IC was observed with clone SP263, followed by 22C3 and SP142, and all clones showed strong agreement in a pairwise comparison, both in TC and IC (R-values: 0.780 to 0.901), which indicates that all 3 clones are potentially useful in the evaluation of PD-L1 expression in UCV.

RNA Expression Profiling of Lymphoepithelioma-Like Carcinoma of the Bladder Reveals a Basal-Like Molecular Subtype

Lymphoepithelioma-like carcinoma of the bladder (LELC-B) is a rare subtype of urothelial carcinoma consisting of undifferentiated epithelial cells within a dense inflammatory cell infiltrate. We set out to molecularly characterize LELC-B through RNA expression profiling as well as immunohistochemistry (IHC) to understand its underlying biology. Sixteen cases of LELC-B were identified at Johns Hopkins University. RNA sequencing was performed on 14 cases. IHC staining for programmed cell death ligand 1 (PD-L1) and mismatch repair proteins MutL homolog 1 (MLH1), MutS homolog 2 (MSH2), MSH6, and PMS1 homolog, mismatch repair system component 2 (PMS2) was performed. Transcriptomic profiling of LELC-B showed that they are enriched in a basal-like phenotype, with 12 of 14 LELC-B cases correlating to the basal centroid of the bladder cancer analysis of subtypes by gene expression 47 (BASE47) predictive analysis of microarrays (PAM) classifier. Gene signature analysis confirmed the lymphocyte infiltration profile consistent with the histomorphology. LELC-B lacked features to explain the robust lymphocytic infiltrate, such as loss of mismatch repair protein expression or expression of Epstein-Barr virus transcripts. Nonetheless, PD-L1 IHC was positive in 93% of LELC cases. Our study demonstrates that LELC-B tumors are enriched in a basal-like molecular subtype and share a high level of immune infiltration and PD-L1 expression, similar to basal tumors. The basal-like phenotype is consistent with the known sensitivity of LELC-B to chemotherapy and suggests that immune checkpoint therapy should be explored in this rare disease.

PD-L1 and p16 Expression in Penile Squamous Cell Carcinoma From an Endemic Region

BACKGROUND

Penile squamous cell carcinoma (PSCC) is a rare malignancy with higher incidence in developing countries. Treatment options include surgery, radiation therapy, and systemic chemotherapy. However, effective treatments for advanced disease are lacking. To understand the biology underlying PSCC may help the development of new therapeutic strategies. The objective of this study was to evaluate immunohistochemical expression of programmed death-ligand 1 (PD-L1) and p16 in PSCC and its association with clinicopathologic features and outcomes.

PATIENTS AND METHODS

A cohort of 40 patients with PSCC from an academic institution in Brazil was analyzed. Clinicopathologic features and outcomes were retrospectively collected. PD-L1 and p16 immunohistochemical expression were performed in formalin-fixed paraffin-embedded specimens. PD-L1 was positive with any staining in more than 1% of tumor, and p16 was positive in more than 10%. Associations were performed using the Mann-Whitney and Fisher exact test. Kaplan-Meier curves were used to estimate survival rates with log-rank.

RESULTS

Of 35 patients, 5 were excluded, 4 owing to a lack of data and 1 owing to no tumor available; 18 (51.4%) patients were PD-L1-positive (PD-L1⁺). PD-L1⁺ was associated with larger tumors (P = .027). There was an association between PD-L1⁺ and p16 expression (P = .002). PD-L1⁺ was more frequent in grade II and III disease than grade I (77.8% vs. 22.2%) and was expressed in all patients with grade III disease. Lymph node involvement was associated with PD-L1 expression (69.2% PD-L1⁺ vs. 30.8% PD-L1-negative). The 5-year mortality was 37.1%.

CONCLUSION

PD-L1 expression appears to be associated with p16 expression, larger tumors, and worse clinical outcomes in PSCC and may provide clinical data for new studies to evaluate anti-PD-L1 immune therapies.

The Role of the Lymphocyte Functional Crosstalk and Regulation in the Context of Checkpoint Inhibitor Treatment-Review

During the last decade, the dynamics of the cellular crosstalk have highlighted the significance of the host vs. tumor interaction. This resulted in the development of novel immunotherapeutic strategies in order to modulate/inhibit the mechanisms leading to escape of tumor cells from immune surveillance. Different monoclonal antibodies directed against immune checkpoints, e.g., the T lymphocyte antigen 4 and the programmed cell death protein 1/ programmed cell death ligand 1 have been successfully implemented for the treatment of cancer. Despite their broad activity in many solid and hematologic tumor types, only 20–40% of patients demonstrated a durable treatment response. This might be due to an impaired T cell tumor interaction mediated by immune escape mechanisms of tumor and immune cells as well as alterations in the composition of the tumor microenvironment, peripheral blood, and microbiome. These different factors dynamically regulate different steps of the cancer immune process thereby negatively interfering with the T cell –mediated anti-tumoral immune responses. Therefore, this review will summarize the current knowledge of the different players involved in inhibiting tumor immunogenicity and mounting resistance to checkpoint inhibitors with focus on the role of tumor T cell interaction. A better insight of this process might lead to the development of strategies to revert these inhibitory processes and represent the rational for the design of novel immunotherapies and combinations in order to improve their efficacy.

Clinical impact of T cells, B cells and the PD-1/PD-L1 pathway in muscle invasive bladder cancer: a comparative study of transurethral resection and cystectomy specimens

In patients with muscle invasive bladder cancer (MIBC), neoadjuvant chemotherapy (NAC) prior to radical cystectomy has improved survival but there is an urgent unmet need to identify prognostic and predictive biomarkers to stratify patients who will benefit from treatment. This study aimed to examine the composition of tumor-infiltrating immune cells in MIBC, with particular reference to the clinical outcome and the potential modifying effect of NAC. To this end, the expression of CD8⁺ and FoxP3⁺ T cells, CD20⁺ B cells, PD-1⁺ and PD-L1⁺ immune cells and PD-L1⁺ tumor cells was evaluated by immunohistochemistry on tissue microarrays with paired transurethral resection (TURB) specimens, cystectomy specimens and lymph node metastases from 145 patients, 65 of whom had received NAC. Kaplan–Meier and Cox regression analyses were applied to assess the impact of investigated cell subsets on time to recurrence (TTR). In cystectomy specimens, high infiltration of the investigated immune cell populations, but not PD-L1⁺ tumor cells, were independently associated with a prolonged TTR, whereas in TURB specimens, this association was only seen for CD8⁺ lymphocytes. An additive beneficial prognostic effect of NAC was seen for the majority of the cell subsets but there was no significant interaction between any immune marker and NAC in relation to TTR. Furthermore, no differences in cell densities prior to NAC treatment were observed between complete and non-complete responders, or pre- and posttreatment in non-complete responders. In conclusion, immune cell infiltration provides important prognostic information in both pre- and postsurgical samples of MIBC, independently of NAC.

Clinicopathological and prognostic value of PD-L1 in urothelial carcinoma: a meta-analysis

Objective: Our objective was to conduct a meta-analysis to investigate the clinicopathological features and prognostic value of programmed cell death ligand 1 (PD-L1) expression in patients with urothelial carcinoma (UC).

Materials and methods: Twenty-seven studies with 4,032 patients were included in the meta-analysis. Pooled ORs and 95% CIs were used to examine the associations between clinical factors and PD-L1 expression. HRs and 95% CIs were extracted from eligible studies. Heterogeneity was evaluated using the chi-squared-based Q test and I² statistic.

Results: Expression of PD-L1 on tumor cells (TCs) was associated with muscle-invasive disease (OR=3.67, 95% CI: 2.53–5.33), and inversely associated with the history of intravesical bacilli Calmette-Guerin therapy (OR=0.39, 95% CI: 0.18–0.82) in bladder cancer patients. PD-L1 expression on TCs was associated with worse overall survival (HR=2.06, 95% CI: 1.38–3.06) in patients with organ-confined bladder cancer. PD-L1 expression in patients with UC was significantly related to better objective response rate after PD-1/PD-L1 antibody treatment.

Conclusions: Expression of PD-L1 on TCs was associated with muscle-invasive disease in patients with bladder cancer. Patients with PD-L1-positive UC had a significantly better response to PD-1/PD-L1 targeted treatment.

Single-Cell Genomics

BACKGROUND

Single-cell genomics is an approach to investigate cell heterogeneity and to identify new molecular features correlated with clinical outcomes. This approach allows identification of the complexity of cell diversity in a sample without the loss of information that occurs when multicellular or bulk tissue samples are analyzed.

CONTENT

The first single-cell RNA-sequencing study was published in 2009, and since then many more studies and single-cell sequencing methods have been published. These studies have had a major impact on several fields, including microbiology, neurobiology, cancer, and developmental biology. Recently, improvements in reliability and the development of commercial single-cell isolation platforms are opening the potential of this technology to the clinical laboratory.

SUMMARY

In this review we provide an overview of the current state of single-cell genomics. We describe opportunities in clinical research and medical applications.

Immunotherapy for Urothelial Carcinoma: Current Evidence and Future Directions

PURPOSE OF REVIEW

Until recently, effective treatment options for patients with advanced urothelial carcinoma were limited to platinum-based chemotherapy. In the post-platinum setting and for patients ineligible for cisplatin, minimally effective second-line chemotherapy was used and outcomes were poor. The approval of immune checkpoint inhibitors has significantly changed the treatment landscape of urothelial carcinoma. Here, we review current data demonstrating their efficacy in advanced disease and ongoing trials investigating novel combination strategies.

RECENT FINDINGS

Since May 2016, five agents targeting the programmed cell death 1 (PD-1) pathways have been approved for use after progression on platinum-based chemotherapy. Further, atezolizumab and pembrolizumab are approved for use in cisplatin-ineligible patients with high programmed death-ligand 1 (PD-L1) expression. Preliminary studies have shown their safety and efficacy as neoadjuvant therapy in muscle-invasive bladder cancer. Several ongoing trials are investigating these agents in combination with radiation therapy, platinum-based chemotherapy, other immune checkpoint inhibitors, and targeted agents. Immune checkpoint inhibitors have demonstrated durable efficacy in patients with advanced urothelial carcinoma as first- and second-line therapy. Ongoing studies will help define the optimal sequence, combination strategies, and predictive biomarkers of response.

Immune phenotype of peripheral blood mononuclear cells in patients with high-risk non-muscle invasive bladder cancer

PURPOSE

To explore the immune phenotype of peripheral blood mononuclear cells (PBMC) in patients with high-risk non-muscle invasive bladder cancer (NMIBC).

METHODS

We prospectively collected blood samples from patients with high-risk NMIBC treated at our institution. PBMC were analyzed by flow cytometry to determine the frequency of T cells and NK cells and the expression of immunoregulatory molecules (Tim-3, TIGIT and PD-1). PBMC from healthy donors (HD) were included for comparison, and associations with response to BCG were investigated.

RESULTS

A total of 38 patients were included, 19 BCG responders and 19 BCG refractory. Compared to 16 PBMC from HD, the frequency of total NK cells was significantly higher in patients with NMIBC [15.2% (IQR: 11.4, 22.2) vs. 5.72% (IQR: 4.84, 9.79); p = 0.05], whereas the frequency of T cells was not statistically different. Both Tim-3 and TIGIT expressions were significantly higher in NMIBC compared to HD, particularly in NK cells [13.8% (11.0; 22.4) vs. 5.56% (4.20; 10.2) and 34.9% (18.9; 53.5) vs. 1.82% (0.63; 5.16), respectively; p < 0.001]. Overall, the expression of PD-1 in all cell types was low in both NMIBC patients and HD. The immune phenotype was not significantly different before and after initiation of BCG. However, the proportion of CD8+ T cells before BCG was significantly higher in responders.

CONCLUSION

The immune phenotype of PBMC from patients with high-risk NMIBC was significantly different from HD, regardless of the presence of disease or the initiation of BCG. Peripheral CD8+ T cells could play a role in response to BCG.

Immune checkpoint inhibitors as a real hope in advanced urothelial carcinoma

Metastatic urothelial cancer is an aggressive disease associated with a poor prognosis. In the first-line setting, platinum-based chemotherapy is the standard of care but resistance rapidly occurs. After failure of platinum-based therapy and in cisplatin-ineligible patients, therapeutic options are limited. Malignant cells evolve mechanisms to evade immune recognition, including the expression of cell-surface molecules, named immune checkpoints, on tumor and tumor-specific lymphocytes. Immunotherapy, by targeting these checkpoints, represents a new tool to improve the patient outcome in advanced urothelial carcinoma (UC). Recently, the US FDA approved, in a short time, several immune checkpoint inhibitors in metastatic UC, both after failure of platinum-based therapy and in first-line setting in cisplatin-ineligible patients. This article aims to review the place of immunotherapy in advanced UC.

Urothelial carcinoma is an aggressive disease and therapeutic options are limited in patients with advanced stage who are refractory to chemotherapy. Immunotherapy represents a milestone for these patients; different immune checkpoint inhibitors have shown significant activity in advanced urothelial carcinoma and are currently available both in the second-line metastatic setting (after failure of platinum-based therapy) and in the first-line setting in cisplatin-ineligible patients. Furthermore, these agents are better tolerated than chemotherapy. PD-L1 expression is not an ideal biomarker and further research is evaluating innovative methods to facilitate selection of patients who are most likely to benefit from these agents.

The prognostic value of PD-L1 expression in upper tract urothelial carcinoma varies according to platelet count

Programmed cell death ligand-1 (PD-L1) is a ligand for programmed cell death-1 (PD-1) that negatively regulates T-cell activation and plays a crucial role in suppressing anti-tumor host immunity. Although PD-L1 is a promising immunotherapy target in various cancers, including urothelial carcinoma (UC), the prognostic significance of PD-L1 in UC is unclear. As platelets help protect tumor cells from immune elimination in the circulatory system, we hypothesized that tumor PD-L1 and circulating platelets might synergistically promote tumor metastasis, and that the prognostic significance of PD-L1 might vary according to platelet count. We immunohistochemically examined tumor PD-L1 expression in 271 patients with upper tract UC, which revealed PD-L1 positivity in 31 of 271 cases (11%). The associations of tumor PD-L1 expression with outcomes varied among patients with high or low platelet counts (P_interaction  < 0.004). Among patients with high platelet counts (N = 136), PD-L1 positivity (N = 15) was significantly associated with shorter metastasis-free survival (univariate hazard ratio [HR]: 6.23, 95% confidence interval [CI]: 2.95-13.1; multivariate HR: 2.68, 95% CI: 1.27-5.64) and shorter overall survival (univariate HR: 4.92, 95% CI: 2.14-11.3, multivariate HR: 2.78, 95% CI: 1.19-6.51). In contrast, among patients with low platelet counts (N = 135), PD-L1 positivity (N = 16) was not significantly associated with these outcomes. Our results suggest that tumor PD-L1 expression and platelet count might interact and help regulate tumor progression. Although a larger prospective study is needed to validate our findings, this relationship is important to consider, as immunotherapies targeting the PD-1/PD-L1 axis have gained significant attention as promising therapies for UC.

A multicenter round robin test of PD-L1 expression assessment in urothelial bladder cancer by immunohistochemistry and RT-qPCR with emphasis on prognosis prediction after radical cystectomy

Background

Immunohistochemical PD-L1 assessment is currently used to identify responders towards checkpoint inhibitors although it is limited by inter-observer effects. Here, we conducted a multi-center round robin test to prove the possibility of assessing the PD-L1 status by gene expression to avoid inter-observer effects.

Patients and methods

Gene expression of PD-L1 was analyzed in a total of 294 samples (14 cases non-muscle invasive and muscle-invasive bladder cancer; MIBC) in seven centers by a RT-qPCR kit and compared with immunohistochemical scoring of three pathologists (DAKO, 22c3). Both assays were compared towards prognosis prediction in a cohort of 88 patients with MIBC.

Results

PD-L1 gene expression revealed very high inter center correlation (centrally extracted RNA: r = 0.68–0.98, p ≤ 0.0076; locally extracted RNA: r = 0.81–0.98, p ≤ 0.0014). IHC Inter-observer concordance was moderate to substantial for immune cells (IC), fair for combined IC/ tumor cell (TC) (IC: κ = 0.50–0.61; IC + TC: κ = 0.50), and fair for TC scoring (κ = 0.26–0.35). Gene expression assessment resulted in more positive cases (9/14 cases positive vs. 6/14 cases [IHC]) which could be validated in the independent cohort. Positive mRNA status was associated with significantly better overall and disease-specific survival (5-year OS: 50% vs. 26%, p = 0.0042, HR = 0.48; 5 year DSS: 65% vs. 40%, p = 0.012, HR = 0.49). The 1% IHC IC cut-off also revealed significant better OS (5 year OS: 58% vs. 31%, p = 0.036, HR = 0.62).

Conclusion

Gene expression showed very high inter-center agreement. Gene expression assessment also resulted in more positive cases and revealed better prognosis prediction. PD-L1 mRNA expression seems to be a reproducible and robust tool for PD-L1 assessment.