Stromal marker fibroblast activation protein drives outcome in T1 non-muscle invasive bladder cancer

Coupling Habitat Radiomic Analysis with the Diversification of the Tumor ecosystem: Illuminating New Strategy in the Assessment of Postoperative Recurrence of Non-Muscle Invasive Bladder Cancer

RATIONALE AND OBJECTIVES

Non-muscle-invasive bladder cancer (NMIBC) is highly recurrent, with each recurrence potentially progressing to muscle-invasive cancer, affecting patient prognosis. Intratumoral heterogeneity plays a crucial role in NMIBC recurrence. This study investigated a novel habitat-based radiomic analysis for stratifying NMIBC recurrence risk.

MATERIALS AND METHODS

A retrospective collection of 382 NMIBC patients between 2015 and 2021 from two medical institutions was carried out. Patients' CT images were collected across three phases, with tumor sites delineated within the bladder. Intratumoral habitats were identified using K-means clustering on 19 texture features of the tumor sites, followed by the extraction of 107 radiomic features per habitat with PyRadiomics. These features were integrated into machine learning algorithms to develop a habitat-based model (HBM) for predicting two-year recurrence of NMIBC patients. The clinical and multiphase radiomic models were also constructed for comparison, with the Delong test comparing their diagnostic efficiency. The impact of HMB on patients' recurrence-free survival and the correlation between HBM and tumor-stroma ratio were further analyzed.

RESULTS

Three distinct habitats were identified within NMIBC. The HBM showed an AUC of 0.932 (95% CI: 0.906 - 0.958) in the training cohort and 0.782 (95% CI: 0.674 - 0.890) in the validation cohort for predicting two-year recurrence. With comparison between different models, The HBM is demonstrated to possess superior diagnostic efficacy to the clinical model (p < 0.001) in the training cohort. However, no significant difference was noted between the multiphase and clinical models (p = 0.130) in the training cohort. The HBM score effectively distinguished the recurrence-free survival of NIMBC patients and demonstrated a significant correlation with the tumor-stroma ratio.

CONCLUSIONS

Habitat-based radiomics, coupled with machine learning, efficiently predicts NMIBC recurrence. Further research on habitat-based radiomics offers potential improvement in clinical management of NMIBC.

Cancer-associated fibroblasts as therapeutic targets for cancer: advances, challenges, and future prospects

Research into cancer treatment has been mainly focused on developing therapies to directly target cancer cells. Over the past decade, extensive studies have revealed critical roles of the tumour microenvironment (TME) in cancer initiation, progression, and drug resistance. Notably, cancer-associated fibroblasts (CAFs) have emerged as one of the primary contributors in shaping TME, creating a favourable environment for cancer development. Many preclinical studies have identified promising targets on CAFs, demonstrating remarkable efficacy of some CAF-targeted treatments in preclinical models. Encouraged by these compelling findings, therapeutic strategies have now advanced into clinical evaluation. We aim to provide a comprehensive review of relevant subjects on CAFs, including CAF-related markers and targets, their multifaceted roles, and current landscape of ongoing clinical trials. This knowledge can guide future research on CAFs and advocate for clinical investigations targeting CAFs.

Fibroblast Activation Protein-α and the Immune Landscape: Unraveling T1 Non-muscle-invasive Bladder Cancer Progression

Background and objective

The tumor microenvironment (TME) in non-muscle-invasive bladder cancer (NMIBC) plays an important role in the anticancer response. We aimed to identify the prognostic biomarkers in the TME of patients with NMIBC for progression to ≥T2.

Methods

From our institutional database, 40 patients with T1 high-risk NMIBC who progressed were pair matched for Club Urologico Español de Tratamiento Oncologico (CUETO) progression variables with 80 patients who never progressed despite longer follow-up. Progression was defined as ≥T2 or extravesical disease. Patients were treated at least with bacillus Calmette-Guérin (BCG) induction (five or more of six doses). Immunohistochemical (IHC) markers for the TME were used on tissue at first T1 diagnosis: CD8-PanCK, GZMB-CD8-FOXP3, CD163, PD-L1 SP142/SP263, fibroblast activation protein-α (FAP), and CK5-GATA3. Full tissue slides were annotated digitally. Relative marker area (IHC-positive area/total area) or density (IHC-positive cells per area; n/mm2) was calculated, differentiating between regions of interest (ROIs; T1, Ta, and carcinoma in situ) and between compartments (stromal, epithelial, and combined). Differences in IHC variables were assessed using the t test, for continuous variables using analysis of variance and comparisons of more than two groups using Tukey's test. Conditional logistic regression for progression at 5-yr follow-up was performed with clusters based on pair matching.

Key findings and limitations

Only FAP expression (increase per 50%) in T1 (odds ratio [OR]: 1.33; 95% confidence interval [CI]: 1.04-1.70) and all ROIs combined (OR: 1.62; 95% CI: 1.14-2.29) correlated significantly with progression. None of the other clinicopathological/IHC variables correlated with progression.

Conclusions and clinical implications

FAP is a potential prognostic biomarker for progression in high-risk NMIBC. FAP is a marker for cancer-associated fibroblasts and is linked to immunosuppression and neoangiogenesis, which makes future investigation clinically relevant.

Patient summary

We found that progression of high-risk non-muscle-invasive bladder cancer to muscle-invasive disease is less in patients with lower fibroblast activation protein-α (FAP) expression, which is a marker for cancer-associated fibroblasts.

Association of future cancer metastases with fibroblast activation protein-α: a systematic review and meta-analysis

Introduction

Fibroblast activation protein-α (FAP-α) is a vital surface marker of cancer-associated fibroblasts, and its high expression is associated with a higher tumor grade and metastasis. A systematic review and a meta-analysis were performed to associate future metastasis with FAP-α expression in cancer.

Methods

In our meta-analysis, relevant studies published before 20 February 2024 were systematically searched through online databases that included PubMed, Scopus, and Web of Science. The association between FAP-α expression and metastasis, including distant metastasis, lymph node metastasis, blood vessel invasion, vascular invasion, and neural invasion, was evaluated. A pooled odds ratio (OR) with 95% confidence intervals (CI) was reported as the measure of association.

Results

A total of 28meta-analysis. The random-effects model for five parameters showed that a high FAP-α expression was associated with blood vessel invasion (OR: 3.04, 95% CI: 1.54-5.99, I 2 = 63%, P = 0.001), lymphovascular invasion (OR: 3.56, 95% CI: 2.14-5.93, I 2 = 0.00%, P < 0.001), lymph node metastasis (OR: 2.73, 95% CI: 1.96-3.81, I 2 = 65%, P < 0.001), and distant metastasis (OR: 2.59; 95% CI: 1.16-5.79, I 2 = 81%, P < 0.001). However, our analysis showed no statistically significant association between high FAP-α expression and neural invasion (OR: 1.57, 95% CI: 0.84-2.93, I 2 = 38%, P = 0.161).

Conclusions

This meta-analysis indicated that cancer cells with a high FAP-α expression have a higher risk of metastasis than those with a low FAP-α expression. These findings support the potential importance of FAP-α as a biomarker for cancer metastasis prediction.

Tumour microenvironment as a predictive factor for immunotherapy in non-muscle-invasive bladder cancer

Bladder cancer (BC) can be divided into two subgroups depending on invasion of the muscular layer: non-muscle-invasive bladder cancer (NMIBC) and muscle-invasive bladder cancer (MIBC). Its aggressiveness is associated, inter alia, with genetic aberrations like losses of 1p, 6q, 9p, 9q and 13q; gain of 5p; or alterations in the p53 and p16 pathways. Moreover, there are reported metabolic disturbances connected with poor diagnosis-for example, enhanced aerobic glycolysis, gluconeogenesis or haem catabolism.Currently, the primary way of treatment method is transurethral resection of the bladder tumour (TURBT) with adjuvant Bacillus Calmette-Guérin (BCG) therapy for NMIBC or radical cystectomy for MIBC combined with chemotherapy or immunotherapy. However, intravesical BCG immunotherapy and immune checkpoint inhibitors are not efficient in every case, so appropriate biomarkers are needed in order to select the proper treatment options. It seems that the success of immunotherapy depends mainly on the tumour microenvironment (TME), which reflects the molecular disturbances in the tumour. TME consists of specific conditions like hypoxia or local acidosis and different populations of immune cells including tumour-infiltrating lymphocytes, natural killer cells, neutrophils and B lymphocytes, which are responsible for shaping the response against tumour neoantigens and crucial pathways like the PD-L1/PD-1 axis.In this review, we summarise holistically the impact of the immune system, genetic alterations and metabolic changes that are key factors in immunotherapy success. These findings should enable better understanding of the TME complexity in case of NMIBC and causes of failures of current therapies.

Expression of GLUT4 and FAP in urothelial bladder carcinoma: correlation with angiogenesis and clinicopathological characteristics

Background

Urothelial carcinoma (UC) is the most common type of bladder cancer. Glucose transporter 4 (GLUT4) is one of glucose transporter proteins’ family which facilitates glucose transport inside the cells. It was found to be overexpressed in several malignant tumors. Cancer-associated fibroblasts (CAFs) are heterogeneous stromal cells located adjacent to cancer cells and are considered one of the most important tumor stromal cells. They have been associated with enhancing tumor growth and invasion. GLUT4 expression in malignant epithelial cells and fibroblast activation protein (FAP) expression in CAFs of UC in relation to angiogenesis and clinicopathological characteristics are studied in this work.

Materials and methods

The study was carried out on 72 paraffin blocks of UC (27 radical cystectomies and 45 transurethral resections). Immunohistochemical staining was performed with GLUT4, FAP, and CD34 antibodies. Expression of GLUT4 and FAP was classified according to the staining intensities and percentages into low and high groups. CD34-stained microvessels’ mean count in five microscopic fields (×200) was taken as the microvessel density (MVD).

Results

GLUT4 overexpression was detected in 32 UC. It was significantly associated with high-grade tumors, advanced primary tumor (pT) stage, lymphovascular invasion (LVI), and regional lymph node invasion. High FAP expression was appreciated in 27 UC and was significantly linked to LVI and advanced TNM staging. Intratumor MVD significantly increased in UC with muscle invasion, LVI, and regional lymph node and/or distant metastasis. A significant positive correlation between GLUT4, FAP expression, and MVD was found.

Conclusion

GLUT4 and FAP expression was significantly associated with increased intratumor MVD and adverse clinicopathological factors.

Non-muscle invasive bladder cancer biomarkers beyond morphology

Non-muscle invasive bladder cancer (NMIBC) still represents a challenge in decision-making and clinical management since prognostic and predictive biomarkers of response to treatment are still under investigation. In addition to the risk factors defined by EORTC guidelines, histological features have also been considered key variables able to impact on recurrence and progression in bladder cancer. Conversely, the role of genomic rearrangements or expression of specific proteins at tissue level need further assessment in NMIBC. As with muscle-invasive cancer, NMIBC is a heterogeneous disease, characterized by genomic instability, varying rates of mutation and a wide range of protein tissue expression. In this Review, we summarized the recent evidence on prognostic and predictive tissue biomarkers in NMIBC, beyond morphological parameters, outlining how they could affect tumor biology and consequently its behavior during clinical care. Our aim was to facilitate clinical evaluation of promising biomarkers that may be employed to better stratify patients. We described the most common molecular events and immunohistochemical protein expressions linked to recurrence and progression. Moreover, we discussed the link between available treatments and molecular drivers that could be predictive of clinical response. In conclusion, we foster further investigations with particular focus on immunohistochemical evaluation of tissue biomarkers, a promising and cost-effective tool for daily practice.

(Pro)renin Receptor Is a Novel Independent Prognostic Marker in Invasive Urothelial Carcinoma of the Bladder

Simple Summary

This is a novel description of (Pro)renin receptor (PRR) protein and its prognostic role in invasive urothelial cancer of the bladder. Using a tissue microarray, we investigated PRR expression and other immunohistochemical markers including p53, immune-checkpoint inhibition, and basal and luminal phenotypes in a series of patients with invasive urothelial carcinoma of the bladder treated with radical cystectomy. PRR expression is an independent prognostic marker and could be a potential target in urothelial carcinoma that should be further investigated.

Abstract

(Pro)renin receptor (PRR) is being investigated in several malignancies as it activates pathogenic pathways that contribute to cell proliferation, immunosuppressive microenvironments, and acquisition of aggressive neoplastic phenotypes. Its implication in urothelial cancer (UC) has not been evaluated so far. We retrospectively evaluate the prognostic role of PRR expression in a series of patients with invasive UC treated with radical cystectomy and other clinical and histopathological parameters including p53, markers of immune-checkpoint inhibition, and basal and luminal phenotypes evaluated by tissue microarray. Cox regression analyses using stepwise selection evaluated candidate prognostic factors and disease-specific survival. PRR was expressed in 77.3% of the primary tumors and in 70% of positive lymph nodes. PRR expression correlated with age (p = 0.006) and was associated with lower preoperatively hemoglobin levels. No other statistical association was evidenced with clinical and pathological variables (gender, ASA score, Charlson comorbidity index, grade, pT, pN) or immunohistochemical expressions evaluated (CK20, GA-TA3, CK5/6, CD44, PD-L1, PD-1, B7-H3, VISTA, and p53). PRR expression in primary tumors was associated with worse survival (log-rank, p = 0.008). Cox regression revealed that PRR expression (HR 1.85, 95% CI 1.22–2.8), pT (HR 7.02, 95% CI 2.68–18.39), pN (HR 2.3, 95% CI 1.27–4.19), and p53 expression (HR 1.95, 95% CI 1.1–3.45) were independent prognostic factors in this series. In conclusion, we describe PRR protein and its prognostic role in invasive UC for the first time. Likely mechanisms involved are MAPK/ERK activation, Wnt/β-catenin signaling, and v-ATPAse function.