The need for immune biomarkers for treatment prognosis and response in genitourinary malignancies

Whole-Organ Genomic Characterization of Mucosal Field Effects Initiating Bladder Carcinogenesis

We used whole-organ mapping to study the locoregional molecular changes in a human bladder containing multifocal cancer. Widespread DNA methylation changes were identified in the entire mucosa, representing the initial field effect. The field effect was associated with subclonal low-allele frequency mutations and a small number of DNA copy alterations. A founder mutation in the RNA splicing gene, ACIN1, was identified in normal mucosa and expanded clonally with an additional 21 mutations in progression to carcinoma. The patterns of mutations and copy number changes in carcinoma in situ and foci of carcinoma were almost identical, confirming their clonal origins. The pathways affected by the DNA copy alterations and mutations, including the Kras pathway, were preceded by the field changes in DNA methylation, suggesting that they reinforced mechanisms that had already been initiated by methylation. The results demonstrate that DNA methylation can serve as the initiator of bladder carcinogenesis.

The Interplay between Inflammation, Anti-Angiogenic Agents, and Immune Checkpoint Inhibitors: Perspectives for Renal Cell Cancer Treatment

Treatment options for metastatic renal cell carcinoma (RCC) have been expanding in the last years, from the consolidation of several anti-angiogenic agents to the approval of immune checkpoint inhibitors (ICIs). The rationale for the use of immunomodulating agents derived from the observation that RCC usually shows a diffuse immune-cell infiltrate. ICIs target Cytotoxic T Lymphocytes Antigen 4 (CTLA-4), programmed death 1 (PD-1), or its ligand (PD-L1), showing promising therapeutic efficacy in RCC. PD-L1 expression is associated with poor prognosis; however, its predictive role remains debated. In fact, ICIs may be a valid option even for PD-L1 negative patients. The establishment of valid predictors of treatment response to available therapeutic options is advocated to identify those patients who could benefit from these agents. Both local and systemic inflammation contribute to tumorigenesis and development of cancer. The interplay of tumor-immune status and of cancer-related systemic inflammation is pivotal for ICI-treatment outcome, but there is an unmet need for a more precise characterization. To date, little is known on the role of inflammation markers on PD-1 blockade in RCC. In this paper, we review the current knowledge on the interplay between inflammation markers, PD-1 axis, and anti-angiogenic agents in RCC, focusing on biological rationale, implications for treatment, and possible future perspectives.

Prognostic and Clinicopathological Significance of PD-L1 in Patients With Bladder Cancer: A Meta-Analysis

Background: The prognostic role of programmed cell death-ligand 1 (PD-L1) in bladder cancer has been investigated in previous studies, but the results remain inconclusive. Therefore, we carried out a meta-analysis to evaluate the prognostic significance of PD-L1 in patients with bladder cancer. Methods: The electronic databases PubMed, Embase, Web of Science, and Cochrane Library were searched. The association between PD-L1 expression and survival outcomes and clinicopathological factors was analyzed by hazard ratios (HRs) or odds ratios (ORs) and 95% confidence intervals (CIs). Results: A total of 11 studies containing 1,697 patients were included in the meta-analysis. High PD-L1 expression was associated with poor overall survival (OS) (HR = 1.83, 95% CI = 1.24-2.71, p = 0.002). There was nonsignificant association between PD-L1 and recurrence-free survival (RFS) (HR = 1.43, 95% CI = 0.89-2.29, p = 0.134), cancer-specific survival (CSS) (HR = 1.51, 95% CI = 0.80-2.87, p = 0.203), or disease-free survival (DFS) (HR = 1.53, 95% CI = 0.88-2.65, p = 0.13). Furthermore, high PD-L1 was significantly correlated with higher tumor stage (OR = 3.9, 95% CI = 2.71-5.61, p < 0.001) and distant metastasis (OR = 2.5, 95% CI = 1.22-5.1, p = 0.012), while PD-L1 overexpression was not correlated with sex, tumor grade, lymph node status, and multifocality. Conclusions: The meta-analysis suggested that PD-L1 overexpression could predict worse survival outcomes in bladder cancer. High PD-L1 expression may act as a potential prognostic marker for patients with bladder cancer.

The Identification of Immunological Biomarkers in Kidney Cancers

The recent approval of several agents have revolutionized the scenario of therapeutic management of metastatic renal cell carcinoma (RCC) allowing us to reach important clinical end points with extended patients' survival. Actually, every new drug approved has represented an important step forward to the improvement of patient's survival. On the other hand, we now understand that RCC includes a large group of tumor entities, each of them with different genetic and mutational alterations, but also showing different clinical behavior; a reason behind the needs of subtype specific personalized approach to therapy of RCC. Immunotherapy is gradually becoming a key factor in the therapeutic algorithm for patients with locally advanced or metastatic RCC. Due to the combination of potent treatment success and potentially deadly adverse effects from immune checkpoint inhibitors (ICI), gathering prognostic and predictive information about FDA-indicated tumors seems to be prudent. Robust and reliable biomarkers are crucial for patient's selection of treatments with immunomodulatory drugs. PD-L1 expression is a poor prognostic factor and predictive of better responses from both PD-1 and PD-L1 inhibitors in a variety of tumor types including RCC. Each FDA approved PD-1/PD-L1 drug is paired with a PD-L1 Immunohistochemistry (IHC) assay. Thus, there is need for improved knowledge and application of PD-1/PD-L1 IHC biomarkers in daily practice. IHC staining appears in membranous fashion. The atezolizumab approved IHC assay is unique in that only immune cell staining is quantified for the use of this assay in RCC. A single biomarker for patient selection may not be feasible, given that immune responses are dynamic and evolve over time. Biomarker development for ICI drugs will likely require integration of multiple biologic components like PD-L1 expression, TILs and mutational load. New methodological approaches based on digital pathology may be relevant since they will allow recognition of the biomarker and to objectively quantitate its expression, and therefore might produce objective and reproducible cut-off assessment. Multidisciplinary approach is very much needed to fully develop the current and future value of ICI in clinical practice.

Immunotherapy in renal cell carcinoma: latest evidence and clinical implications

Advances in understanding the mechanisms of tumour-induced immunosuppression have led to the development of immune-checkpoint inhibitors in cancer patients, including those with renal cell carcinoma (RCC). The optimal combination between immunotherapy and targeted agents (as well as the possible favourable sequential therapy of these two classes of drugs) remains an open question at this moment. Several trials are currently underway to assess the combination of anti-programmed-death 1 (PD-1) or anti-PD-ligand(L)1 agents with other immunotherapies or with anti-vascular endothelial growth factor receptor (VEGFR) tyrosine kinase inhibitors (TKIs). In this editorial, we described the results of the most recent clinical trials on the use of immunotherapies in RCC and the emerging data on the research for reliable biomarkers of tumour response in this setting. In addition, we have focused on the role of the gut microbiome and tumour microenvironment in the development of future therapeutic strategies for RCC patients.