Androgen receptor and immune cell PD-L1 expression in bladder tumors predicts disease recurrence and survival

Immunotherapy and radiotherapy for older patients with invasive bladder cancer unfit for surgery or chemotherapy: practical proposal by the international geriatric radiotherapy group

The standard of care for non-metastatic muscle invasive bladder cancer is either radical cystectomy or bladder preservation therapy, which consists of maximal transurethral bladder resection of the tumor followed by concurrent chemoradiation with a cisplatin-based regimen. However, for older cancer patients who are too frail for surgical resection or have decreased renal function, radiotherapy alone may offer palliation. Recently, immunotherapy with immune checkpoint inhibitors (ICI) has emerged as a promising treatment when combined with radiotherapy due to the synergy of those two modalities. Transitional carcinoma of the bladder is traditionally a model for immunotherapy with an excellent response to Bacille Calmette-Guerin (BCG) in early disease stages, and with avelumab and atezolizumab for metastatic disease. Thus, we propose an algorithm combining immunotherapy and radiotherapy for older patients with locally advanced muscle-invasive bladder cancer who are not candidates for cisplatin-based chemotherapy and surgery.

The sex gap in bladder cancer survival - a missing link in bladder cancer care?

The differences in bladder cancer outcomes between the sexes has again been highlighted. Uncommon among cancers, bladder cancer outcomes are notably worse for women than for men. Furthermore, bladder cancer is three to four times more common among men than among women. Factors that might explain these sex differences include understanding the importance of haematuria as a symptom of bladder cancer by both clinicians and patients, the resultant delays in diagnosis and referral of women with haematuria, and health-care access. Notably, these factors seem to have geographical variation and are not consistent across all health-care systems. Likewise, data relating to sex-specific treatment responses for patients with non-muscle-invasive or muscle-invasive bladder cancer are inconsistent. The influence of differences in the microbiome, bladder wall thickness and urine dwell times remain to be elucidated. The interplay of hormone signalling, gene expression, immunology and the tumour microenvironment remains complex but probably underpins the sexual dimorphism in disease incidence and stage and histology at presentation. The contribution of these biological phenomena to sex-specific outcome differences is probable, albeit potentially treatment-specific, and further understanding is required. Notwithstanding these aspects, we identify opportunities to harness biological differences to improve treatment outcomes, as well as areas of fundamental and translational research to pursue. At the level of policy and health-care delivery, improvements can be made across the domains of patient awareness, clinician education, referral pathways and guideline-based care. Together, we aim to highlight opportunities to close the sex gap in bladder cancer outcomes.

The androgen receptor in bladder cancer

Bladder cancer is the ninth most common cancer worldwide with a striking sex-based difference in incidence. Emerging evidence indicates that the androgen receptor (AR) might promote the development, progression and recurrence of bladder cancer, contributing to the observed sex differences. Targeting androgen-AR signalling has promise as potential therapy for bladder cancer and helps to suppress progression of this disease. In addition, the identification of a new membrane AR and AR-regulated non-coding RNAs has important implications for bladder cancer treatment. The success of human clinical trials of targeted-AR therapies will help in the development of improved treatments for patients with bladder cancer.

Androgen receptor transcriptionally inhibits programmed death ligand-1 (PD-L1) expression and influences immune escape in bladder cancer

In multiple clinical trials, immune checkpoint blockade-based immunotherapy has shown significant therapeutic efficacy in bladder cancer (BCa). Sex is closely related to the incidence rate and prognosis of BCa. As one of the sex hormone receptors, the androgen receptor (AR) is a well-known key regulator that promotes the progression of BCa. However, the regulatory mechanism of AR in the immune response of BCa is still unclear. In this study, the expression of AR and programmed cell death-ligand 1 (PD-L1) was negatively correlated in BCa cells, clinical tissues, and tumor data extracted from The Cancer Genome Atlas Bladder Urothelial Carcinoma (TCGA-BLCA) cohort. A human BCa cell line was transfected to alter expression of AR. The results show that AR negatively regulated PD-L1 expression by directly binding to AR response elements (AREs) on the PD-L1 promoter region. In addition, AR overexpression in BCa cells significantly enhanced the antitumor activity of co-cultured CD8+ T cells. Injection of anti-PD-L1 monoclonal antibodies into C3H/HeN mice significantly suppressed tumor growth, and stable expression of AR dramatically enhanced the antitumor activity in vivo. In conclusion, this study describes a novel role of AR in regulating the immune response to BCa by targeting PD-L1, thus providing potential therapeutic strategies for immunotherapy in BCa.

Prognostic value of programmed cell death ligand-1 expression in patients with bladder urothelial carcinoma undergoing radical cystectomy: A meta-analysis

Background

Radical cystectomy and removal of pelvic lymph nodes (RC-PLND) is a recommended treatment for high-risk non-muscle-invasive and muscle-invasive non-metastatic bladder cancer (BC). However, 50% of patients relapse after RC-PLND. This study aimed to evaluate the effect of programmed cell death ligand-1 (PD-L1) on the prognosis of bladder urothelial carcinoma (BUC) after RC-PLND.

Methods

We present this meta-analysis according to the Preferred Reporting Items for Systematic Review and Meta-Analyses Guidelines. The main outcomes were overall survival (OS), recurrence-free survival (RFS), and cancer-specific survival (CSS) of 3 and 5 years after RC-PLND.

Results

Overall, 11 studies and 1393 BUC cases were included in our meta-analysis. In tumor cells (TCs), the PD-L1 negative group had statistically significant advantage in 5-year OS (risk ratio [RR]: 0.85, 95% confidence interval [CI]: 0.74–0.97, P = 0.02), RFS (RR: 0.76, 95% CI: 0.58–0.99, P = 0.04), and CSS (RR: 0.73, 95% CI: 0.58–0.92, P = 0.009) compared with the PD-L1 positive group. But, no statistically significant difference in 5-year OS and RFS was observed between the PD-L1 negative and positive groups in tumor-infiltrating immune cells.

Conclusions

Our study found that patients with BUC who tested positive for PD-L1 in TCs had a poor prognosis after RC-PLND. PD-1 or PD-L1 inhibitors could be used as a adjuvant medication for patients with BUC after RC-PLND who exhibit PD-L1 overexpression in TCs.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42022301424.

Expression profile and prognostic significance of HOXB13 in rectal cancer

BACKGROUND

This study aimed to investigate the expression pattern and prognostic significance of HOXB13 in rectal cancer.

METHODS

HOXB13 expression in rectal cancer and normal adjacent tissues was detected by reverse transcriptase-polymerase chain reaction and immunohistochemistry, and its clinicopathological characteristics and prognosis were statistically tested. Furthermore, we evaluated the association between tumor immune infiltrating cells and HOXB13 using the tumor immune estimation resource (TIMER) database. The potential biological mechanism associated with HOXB13 overexpression was investigated by gene set enrichment analysis (GSEA).

RESULTS

The expression of HOXB13 messenger RNA and protein in human rectal cancer tissues were significantly higher than those in the normal adjacent tissues (P < 0.05). HOXB13 expression was significantly correlated with depth of invasion, lymphatic invasion, lymph node metastasis, distant metastasis, and pathological tumor node metastasis stage (P < 0.05). Kaplan-Meier survival curves confirmed that HOXB13 overexpression was correlated negatively with overall survival and disease-free survival in rectal cancer (P < 0.05). Also, multivariate Cox regression analysis demonstrated that HOXB13 expression, age, and lymphatic invasion were independent prognostic factors in rectal cancer (P < 0.05). Plus, the results from the TIMER database indicated that HOXB13 expression has a significant association with several immune cell infiltrates. Finally, the GSEA results indicated that HOXB13 participated in the various immune-associated processes, including natural killer cell-mediated cytotoxicity and the T-cell receptor signaling pathway.

CONCLUSION

Our study showed an essential role of HOXB13 in rectal cancer immunity and prognosis. Significantly, the overexpression of HOXB13 leads to the worse prognosis for patients with rectal cancer, which will contribute to understanding molecular mechanisms associated with tumor pathogenesis and prognosis in this disease.

Gender Differences in Urothelial Bladder Cancer: Effects of Natural Killer Lymphocyte Immunity

Men are more likely to develop cancer than women. In fact, male predominance is one of the most consistent cancer epidemiology findings. Additionally, men have a poorer prognosis and an increased risk of secondary malignancies compared to women. These differences have been investigated in order to better understand cancer and to better treat both men and women. In this review, we discuss factors that may cause this gender difference, focusing on urothelial bladder cancer (UBC) pathogenesis. We consider physiological factors that may cause higher male cancer rates, including differences in X chromosome gene expression. We discuss how androgens may promote bladder cancer development directly by stimulating bladder urothelium and indirectly by suppressing immunity. We are particularly interested in the role of natural killer (NK) cells in anti-cancer immunity.

High Androgen Receptor mRNA Expression Is Associated with Improved Outcome in Patients with High-Risk Non-Muscle-Invasive Bladder Cancer

The role of the androgen receptor (AR) in non-muscle-invasive bladder cancer (NMIBC) remains controversial. We retrospectively analyzed the mRNA expression of AR using RT-qPCR in 95 patients with high-risk NMIBC treated with a bladder-sparing approach and correlated AR with clinical data and recurrence-free survival (RFS), cancer-specific survival (CSS), and overall survival (OS). The mRNA expression of AR and KRT5, i.e., the basal-like subtype, was strongly correlated (rs = 0.456; p < 0.001). AR (p = 0.053) and KRT5 (p = 0.029) mRNA expression was negatively correlated with tumor grade. Kaplan–Meier analyses indicated significantly prolonged CSS (p = 0.020) and OS (p = 0.015) and a trend towards longer RFS (p = 0.051) in patients with high AR expression. High KRT5 expression was associated with significantly longer RFS (p = 0.033), CSS (p = 0.029) and OS (p = 0.030), while high KRT20 expression was associated with reduced RFS (p = 0.042). In multivariable analysis, none of the molecular markers was an independent prognostic factor. When performing a substratification with regard to molecular markers and clinicopathological parameters, high AR expression showed improved OS in patients with high KRT20 mRNA expression (p = 0.041). Women showed significantly longer OS in cases with high AR expression (p = 0.011). High AR was associated with significantly improved CSS in males (p = 0.044) and patients with instillation therapy (p = 0.040), while OS was improved regardless of instillation therapy. Younger patients with high AR expression had significantly improved RFS (p = 0.021), CSS (p = 0.014) and OS (p = 0.007). RFS was also improved in patients with high AR and low expression of either KRT5 (p = 0.003) or KRT20 (p = 0.014), but not in patients with high expression of KRT5 or KRT20. In conclusion, high AR mRNA expression is correlated with KRT5 mRNA expression and is associated with an improved outcome in high-risk NMIBC.

Sex Hormone Receptor Signaling in Bladder Cancer: A Potential Target for Enhancing the Efficacy of Conventional Non-Surgical Therapy

There have been critical problems in the non-surgical treatment for bladder cancer, especially residence to intravesical pharmacotherapy, including BCG immunotherapy, cisplatin-based chemotherapy, and radiotherapy. Recent preclinical and clinical evidence has suggested a vital role of sex steroid hormone-mediated signaling in the progression of urothelial cancer. Moreover, activation of the androgen receptor and estrogen receptor pathways has been implicated in modulating sensitivity to conventional non-surgical therapy for bladder cancer. This may indicate the possibility of anti-androgenic and anti-estrogenic drugs, apart from their direct anti-tumor activity, to function as sensitizers of such conventional treatment. This article summarizes available data suggesting the involvement of sex hormone receptors, such as androgen receptor, estrogen receptor-α, and estrogen receptor-β, in the progression of urothelial cancer, focusing on their modulation for the efficacy of conventional therapy, and discusses their potential of overcoming therapeutic resistance.

Switching Cancers: A Systematic Review Assessing the Role of Androgen Suppressive Therapy in Bladder Cancer

CONTEXT

Bladder cancer demonstrates striking gender-based differences in incidence, with a role for androgens possibly implicated in the development and progression of the disease. Emerging preclinical and clinical evidence suggests that there may be a role for antiandrogen therapy in bladder cancer.

OBJECTIVE

This systematic review assessed the current clinical evidence evaluating androgen suppressive therapy (AST) for the treatment or prevention of bladder cancer.

EVIDENCE ACQUISITION

Following Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines, MEDLINE was searched for full-text articles detailing clinical outcomes or incidence of bladder cancer among patients who received AST, defined as gonadotropin-releasing hormone agonists or equivalent, androgen receptor antagonists, or 5-alpha reductase inhibitors.

EVIDENCE SYNTHESIS

A total of 12 studies were included. Five studies focused on prostate cancer patients, with one study in men with lower urinary tract symptoms. Among these studies, a lower incidence of bladder cancer was observed in five, with adjusted risk reduction estimates ranging from 7% to 47%. Six studies evaluating 11 820 bladder cancer patients investigated clinical outcomes among men who received a form of AST. Three out of four studies evaluating recurrence-free survival found a benefit for AST, with adjusted hazard ratios for recurrence of non-muscle-invasive cancer ranging from 0.29 to 0.53. Limitations included large variability in data sources and methodologies, as well as no data on tolerability.

CONCLUSIONS

Current evidence indicates that antiandrogen therapies exert a favorable influence on bladder tumors. Further prospective studies are needed to assess their therapeutic potential.

PATIENT SUMMARY

Androgen suppressive therapy is commonly prescribed for the treatment of prostate-related problems. Prior research indicates that there may be a role for these treatments in patients with bladder cancer. In this review, we evaluate the current evidence that strongly suggests that these agents may be effective against bladder cancer.