Programmed cell death-ligand 1 assessment in urothelial carcinoma: prospect and limitation

Comparison of tissue biomarkers between non-schistosoma and schistosoma-associated urothelial carcinoma

BACKGROUND

High-grade urothelial carcinoma either non-Schistosoma (NS-UBC) or Schistosoma (S-UBC)-associated is the tenth cause of death worldwide and represents a serious therapeutic problem.

AIM

Evaluation of the immmunohistochemical expression of tumor necrosis factor-alpha (TNFα), epidermal growth factor receptor (EGFR), programmed cell death protein-1 (PDL1), estrogen receptor-alpha (ERα) and UroplakinIII, in the high-grade in NS-UBC and S-UBC as potential prognostic and therapeutic targets analyzed through estimation of area percentage, optical density and international pathological scoring system for each marker.

MATERIAL AND METHODS

Sixty high grade urothelial carcinoma cases were enrolled in the study (30 cases of NS-UBC and 30 cases of S-UBC). The cases were immunohistochemically-assessed for TNFα, EGFR, PDL1, ERα and Uroplakin III expression. In S-UBC, parasite load was also evaluated for correlation with the immunohistochemical markers' expression in S-UBC.

RESULTS

The area percentage of immune-expression of TNFα and EGFR was higher in S-UBC compared to NS-UBC. On the other hand, the NS-UBC displayed statistically-higher expression of PDL1 and uroplakinIII (p-value <0.001). ERα revealed higher, yet, non-significant expressions in S-UBC compared to NS-UBC (p-value =0.459). PDL1 expression showed the most superior record regarding area percentage (64.6± 34.5). Regarding optical density, TNF-α showed the highest transmittance expression (2.4 ± 0.9). EGFR positively correlated with PDL1 in S-UBC (r= 0.578, p-value =0.001) whereas in NS-UBC, TNFα and PDL1 (r=0.382, p-value=0.037) had positive correlation. Schistosoma eggs in tissues oppose uroplakin III expression and trigger immunomodulation via PDL1.

CONCLUSION

Due to lower UroplakinIII expression, S-UBC is supposed to have a poorer prognosis. Hormonal therapy is not hypothesized due to a very minimal ERα expression in both NS-UBC and S-UBC. Regarding immunotherapy, anti-TNF-α is suggested for S-UBC whilst in NS-UBC, blockading PDL1 might be useful. Targeted EGFR therapy seems to carry emphasized outcomes in S-UBC. Correlations encourage combined immune therapy in NS-UBC; nevertheless, in S-UBC, combined anti-EGFR and PDL1 seem to be of benefit.

Systemic treatment of advanced and metastatic urothelial cancer: The landscape in Australia

The 5-year survival rate of metastatic urothelial carcinoma (mUC) is estimated to be as low as 5%. Currently, systemic platinum-based chemotherapy followed by avelumab maintenance therapy is the only first-line treatment for mUC that has an overall survival benefit. Cisplatin-based chemotherapy (usually in combination with gemcitabine) is the preferred treatment but carboplatin is substituted where contraindications to cisplatin exist. Treatment with immune checkpoint inhibitors, antibody-drug conjugates, and kinase inhibitors has not yet demonstrated superiority to chemotherapy as first-line therapy and remains investigational in this setting. A recent media release indicates that chemotherapy plus nivolumab gives an OS advantage as first-line treatment but results of this study have not yet been made public. Pembrolizumab remains an option in those having primary progression on first-line chemotherapy or within 12 months of neoadjuvant chemotherapy. The antibody-drug conjugate, enfortumab vedotin has TGA approval for patients whose cancer has progressed following chemotherapy and immunotherapy and has just received a positive Pharmaceutical Benefits Scheme recommendation. The use of molecular screens for somatic genetic mutations, gene amplifications, and protein expression is expanding as drugs that target such abnormalities show promise. However, despite these advances, a substantial proportion of patients with mUC have significant barriers to receiving any treatment, including advancing age, frailty, and comorbidities, and less toxic, effective therapies are needed.

[Practical aspects of PD-L1 assessment in the treatment of urothelial carcinoma: Consensus of the uropathology group of the SEAP]

The recent addition of novel immunotherapy drugs for the treatment of urothelial carcinoma makes it necessary the establishment of criteria to harmonize the immunohistochemical assessment of PD-L1, both as a prognostic factor and for the selection of patients to be treated. In this scenario, a group of uropathologists from the Spanish Society of Pathological Anatomy, together with a medical oncologist as an external collaborator subspecialized in uro-oncology, have prepared this document of recommendations based on the available evidence. During PD-L1 assessment it is especially relevant the selection of the sample, its processing, the immunohistochemical platform and antibody used, and the algorithm applied in the interpretation of results. All these aspects must be indicated in the results report, which should be easily interpretable in a context of rapid evolution of immunological therapies.

Insights on recent innovations in bladder cancer immunotherapy

Bladder carcinoma is the most common genitourinary cancer, with a high prevalence and global incidence. In addition to early detection by cytology, the management of bladder cancer has recently advanced, not only by improvements in conventional treatments such as surgery and chemotherapy, but also through the introduction of immunotherapeutic strategies. The number of approved immunotherapeutic agents has dramatically increased, with various preclinical and clinical applications in cancer drug discovery. Some bladder cancer immunotherapies include immune checkpoint inhibitors, adoptive cell therapy, cytokine-based therapy, bispecific antibodies, and antibody-drug conjugates. This review provides an overview of some of the innovative immunotherapeutic agents approved and in development that can potentially be used in the treatment of bladder cancer.

PD-L1 Testing in Urothelial Carcinoma: Analysis of a Series of 1401 Cases Using Both the 22C3 and SP142 Assays

Immune checkpoint blockade (ICB) drugs are a novel, effective treatment for advanced urothelial carcinoma. Worldwide, several different ICB drugs are approved, each developed and clinically validated with a specific PD-L1 compound diagnostic assay. As a result, PD-L1 testing workflows in routine practice are complex: requiring multiple assays across two platforms, with each assay having a different method of interpretation. Our service tested 1,401 urothelial carcinoma cases for PD-L1 expression, using both the 22C3 PharmDx assay (required prior to Pembrolizumab therapy) and SP142 assay (required prior to Atezolizumab therapy). Of the 1,401 cases tested, 621 cases (44%) were tested with both the 22C3 PharmDx and SP142 assays, 492 cases (35%) with 22C3 PharmDx only, and 288 cases (21%) with SP142 only. Each assay was used and interpreted according to the manufacturer’s guidelines. The rate of positivity we observed was 26% with the 22C3 assay and 31% with the SP142 assay, similar to the pre-licensing studies for both drugs. The discrepancy observed between the assays was 11%, which reinforces the requirement for utilisation of the correct assay for each agent, and limits potential cross-utility of assays. This aspect must be considered when setting up a PD-L1 testing strategy in laboratories where both Pembrolizumab and Atezolizumab are available for the treatment of urothelial carcinoma but also has broader implications for testing of other cancers where multiple ICB drugs and their respective assays are approved.

What Do We Have to Know about PD-L1 Expression in Prostate Cancer? A Systematic Literature Review. Part 1: Focus on Immunohistochemical Results with Discussion of Pre-Analytical and Interpretation Variables

Immunotherapy targeting the PD-1-PD-L1 axis yielded good results in treating different immunologically ''hot'' tumors. A phase II study revealed good therapeutic activity of pembrolizumab in selected prostatic carcinoma (PC)-patients. We performed a systematic literature review (PRISMA guidelines), which analyzes the immunohistochemical expression of PD-L1 in human PC samples and highlights the pre-analytical and interpretation variables. Interestingly, 29% acinar PCs, 7% ductal PCs, and 46% neuroendocrine carcinomas/tumors were PD-L1+ on immunohistochemistry. Different scoring methods or cut-off criteria were applied on variable specimen-types, evaluating tumors showing different clinic-pathologic features. The positivity rate of different PD-L1 antibody clones in tumor cells ranged from 3% (SP142) to 50% (ABM4E54), excluding the single case tested for RM-320. The most tested clone was E1L3N, followed by 22C3 (most used for pembrolizumab eligibility), SP263, SP142, and 28-8, which gave the positivity rates of 35%, 11-41% (depending on different scoring systems), 6%, 3%, and 15%, respectively. Other clones were tested in <200 cases. The PD-L1 positivity rate was usually higher in tumors than benign tissues. It was higher in non-tissue microarray specimens (41-50% vs. 15%), as PC cells frequently showed heterogenous or focal PD-L1-staining. PD-L1 was expressed by immune or stromal cells in 12% and 69% cases, respectively. Tumor heterogeneity, inter-institutional preanalytics, and inter-observer interpretation variability may account for result biases.