Association of tumour microRNA profiling with outcomes in patients with advanced urothelial carcinoma receiving first-line platinum-based chemotherapy

Contemporary Molecular Markers for Predicting Systemic Treatment Response in Urothelial Bladder Cancer: A Narrative Review

The search for dependable molecular biomarkers to enhance routine clinical practice is a compelling challenge across all oncology fields. Urothelial bladder carcinoma, known for its significant heterogeneity, presents difficulties in predicting responses to systemic therapies and outcomes post-radical cystectomy. Recent advancements in molecular cancer biology offer promising avenues to understand the disease's biology and identify emerging predictive biomarkers. Stratifying patients based on their recurrence risk post-curative treatment or predicting the efficacy of conventional and targeted therapies could catalyze personalized treatment selection and disease surveillance. Despite progress, reliable molecular biomarkers to forecast responses to systemic agents, in neoadjuvant, adjuvant, or palliative treatment settings, are still lacking, underscoring an urgent unmet need. This review aims to delve into the utilization of current and emerging molecular signatures across various stages of urothelial bladder carcinoma to predict responses to systemic therapy.

Progress in the development of tissue-based biomarkers for urothelial cancer

INTRODUCTION

As the understanding of molecular mechanisms of bladder cancer advances, molecularly-guided precision medicine becomes increasingly relevant. Biomarkers play a critical role in this setting, predicting treatment response and identifying candidates for targeted therapies.

AREAS COVERED

Current literature on biomarkers in their role in disease prognosis, and response to neoadjuvant and adjuvant therapies. In non-muscle invasive bladder cancer, particular focus is on markers of disease progression, and response to intravesical therapy. In muscle invasive and advanced bladder cancer, particular emphasis is on markers associated with neoadjuvant chemotherapy, as well as systemic immunotherapy. We discuss current shortcomings and pitfalls in contemporary markers, and future avenues of prospective research.

EXPERT OPINION

The focus on biomarkers has moved from immunohistochemical analysis and tumor-related phenotypic changes to examining genetic alterations. Single marker analysis has been shown to be insufficient in predicting both disease course and response to therapy, and studies have shifted towards examining marker combinations and genetic classifiers. Ultimately, significant progress in implementing biomarkers into clinical guidelines remains elusive, largely due to lack of prospective studies in well-defined patient cohorts and with clinically-meaningful endpoints. Until then, despite their promising value, tissue markers should be limited to experimental settings and clinical trials.

Molecular markers of systemic therapy response in urothelial carcinoma

Identification of reliable molecular biomarkers that can complement clinical practice represents a fascinating challenge in any cancer field. Urothelial carcinoma is a very heterogeneous disease and responses to systemic therapies, and outcomes after radical cystectomy are difficult to predict. Advances in molecular biology such as next generation sequencing and whole genome or transcriptomic analysis provide promising platforms to achieve a full understanding of the biology behind the disease and can identify emerging predictive biomarkers. Moreover, the ability to categorize patients' risk of recurrence after curative treatment, or even predict benefit from a conventional or targeted therapies, represents a compelling challenge that may reshape both selection for tailored treatment and disease monitoring. Progress has been made but currently no molecular biomarkers are used in the clinical setting to predict response to systemic agents in either neoadjuvant or adjuvant settings highlighting a relevant unmet need. Here, we aim to present the emerging role of molecular biomarkers in predicting response to systemic agents in urothelial carcinoma.

Identification of a six-lncRNA signature based on a competing endogenous RNA network for predicting the risk of tumour recurrence in bladder cancer patients

Bladder cancer (BC) is the most common malignancy involving the urinary system, and is characterized by a high recurrence rate. It is important to identify potential lncRNA signatures capable of predicting tumour recurrence risk and assessing recurrence prognosis in BC patients. We extracted data from The Cancer Genome Atlas and identified 381 differentially expressed lncRNAs, 855 mRNAs and 70 miRNAs between non-recurrent and recurrent BC tissues. Subsequently, a competing endogenous RNA (ceRNA) network composed of 29 lncRNAs, 13 miRNAs and 4 mRNAs was established. We used univariate and multivariate Cox regression to analyse the relationship between the 29 lncRNAs and recurrence-free survival (RFS) in BC patients. Six lncRNAs had significant prognostic values, and their cumulative risk score indicated that this 6-lncRNA signature independently predicted RFS in BC patients. We applied a receiver operating characteristic (ROC) analysis to assess the efficiency of our prognostic models. High-risk patients exhibited a poorer prognosis than low-risk patients did. Additionally, the 6-lncRNA signature showed a significant correlation with BC clinicopathological characteristics, which indicates that it could be used for effective risk stratification. The current study provides novel insights into the lncRNA-related ceRNA network and this 6-lncRNA signature may be an independent prognostic factor in predicting the recurrence of BC patients.

MicroRNA-371-3 cluster as biomarkers for the diagnosis and prognosis of cancers

Purpose: To date, increasing evidences have demonstrated that the aberrant expression of miR-371–3 cluster has been verified in various cancers and could be potentially used as a biomarker for tumor diagnosis and prognosis. To explore the role of miR-371–3 cluster in tumor diagnosis and prognosis, we conducted this study based on the published data.

Methods: We searched electronic databases (PubMed, EMBASE and Web of Science databases) (Jan 1, 2007 to Jun 1, 2018). The pooled sensitivity, specificity and area under the curve (AUC) of summary receiver operator characteristic (SROC) curve were used for diagnostic values, meanwhile the pooled hazard ration (HR) and 95% CI were used to explore the prognosis capacity of miR-372 and miR-373. In addition, the publication bias of the enrolled studies was tested and a sensitivity analysis of each study was performed to evaluate the stability of the pooled result.

Results: A total of eleven eligible studies containing six eligible studies containing 870 participants for diagnosis and 1218 cancer cases for prognosis were selected for this study. For diagnosis, the pooled results revealed that the miR-371 (sensitivity: 0.85, specificity: 0.92, AUC: 0.92) and miR-373 (sensitivity: 0.81, specificity: 0.93, AUC: 0.93) could be used as diagnostic biomarkers. For prognosis, we observed that elevated miR-372 indicated poor prognosis (HR=2.31, 95% CI: 1.04–5.14), especially in the cutoff value subgroup of median (HR=2.62, 95% CI: 1.54–4.46). In addition, pooled results showed that expression of miR-373 was not related to prognosis because of the significant heterogeneity, and the high miR-373 expression presented favorable prognosis in Asians (HR=0.34, 95% CI: 0.23–0.50) after omitting the study of heterogeneity origin.

Conclusion: The current studies demonstrated that miR-371 and miR-373 could be predictive tumor diagnostic biomarkers and the expression of miR-372 and miR-373 may indicate prognosis of cancer patients.

Circulating Biomarkers in Bladder Cancer

Bladder cancer is a molecularly heterogeneous disease characterized by multiple unmet needs in the realm of diagnosis, clinical staging, monitoring and therapy. There is an urgent need to develop precision medicine for advanced urothelial carcinoma. Given the difficulty of serial analyses of metastatic tumor tissue to identify resistance and new therapeutic targets, development of non-invasive monitoring using circulating molecular biomarkers is critically important. Although the development of circulating biomarkers for the management of bladder cancer is in its infancy and may currently suffer from lower sensitivity of detection, they have inherent advantages owing to non-invasiveness. Additionally, circulating molecular alterations may capture tumor heterogeneity without the sampling bias of tissue biopsy. This review describes the accumulating data to support further development of circulating biomarkers including circulating tumor cells, cell-free circulating tumor (ct)-DNA, RNA, micro-RNA and proteomics to improve the management of bladder cancer.