5α-Reductase Inhibitors Do Not Prevent the Development and Progression of Urothelial Cancer: In Vitro Evidence

Profiling steroid hormone landscape of bladder cancer reveals depletion of intratumoural androgens to castration levels: a cross-sectional study

BACKGROUND

Bladder cancer is a highly over-represented disease in males. The involvement of sex steroids in bladder carcinogenesis and the utilisation of steroid hormone action as a therapeutic target have been frequently proposed. However, the intratumoural steroid milieu remains unclear.

METHODS

We used mass spectrometry and transcriptomic profiling to determine the levels of 23 steroid hormones and the expression of steroidogenic enzymes in primary tumours from patients who underwent transurethral resection (n = 24), and tumours and adjacent morphologically benign bladder tissues from treatment-naïve patients, who underwent radical cystectomy (n = 20). The corresponding steroids were determined from the patients' sera.

FINDINGS

Our results show that both bladder tumours and non-tumour tissues are androgen-poor, with DHT being virtually unquantifiable and testosterone at castration levels. Intratumoural enzymes that inactivate potent androgens (e.g., HSD17B2) exhibited similar tumour aggressiveness-linked downregulation, as reported in advanced forms of classical steroid-dependent cancers, whereas there was little change in the corresponding activating enzymes. Finally, our results suggest cancer aggressiveness-linked dissimilarities in steroid profiles; the patients with overall low circulating steroid levels and those with an association between androgen receptor expression and intratumoural testosterone levels in place had fewer recurrences than the rest.

INTERPRETATION

By revealing the steroid landscape of bladder cancer, our study not only underscores the androgen-poor nature of the malignancy but also identifies potential alterations in steroid profiles that are linked to disease aggressiveness.

FUNDING

The Cancer Foundation Finland, the Finnish State Research Funding (VTR).

Recent advances in the understanding of urothelial tumorigenesis

INTRODUCTION

Patients with non-muscle-invasive bladder tumor suffer from disease recurrence following transurethral surgery even with intravesical pharmacotherapy, while muscle-invasive disease is often deadly. It is therefore critical to elucidate the underlying molecular mechanisms responsible for not only bladder tumor progression but also its tumorigenesis. Indeed, various molecules and/or signaling pathways have been suggested to contribute to the pathogenesis of bladder cancer.

AREAS COVERED

We summarize the progress during the last few years on the initiation or development, but not progression, of urothelial cancer. The clinical implications of these available data, including prognostic significance and possible application for the prevention of the recurrence of non-muscle-invasive bladder tumors, are also discussed.

EXPERT OPINION

Bladder cancer is a heterogeneous group of neoplasms. The establishment of personalized therapeutic options based on the molecular profile in each case should thus be considered. On that account, further accumulation of data on urothelial tumorigenesis is warranted to identify promising targets for the prevention of postoperative tumor recurrence or tumor development in otherwise high-risk patients.

Inhibition of Androgen Signalling Improves the Outcomes of Therapies for Bladder Cancer: Results from a Systematic Review of Preclinical and Clinical Evidence and Meta-Analysis of Clinical Studies

Bladder cancer (BCa) is an endocrine-related tumour and the activation of androgen signalling pathways may promote bladder tumorigenesis. We summarized the available preclinical and clinical evidence on the implications of the manipulation of androgen signalling pathways on the outcomes of BCa therapies. A systematic review was performed in December 2020. We included papers that met the following criteria: original preclinical and clinical research; evaluating the impact of androgen signalling modulation on the outcomes of BCa therapies. Six preclinical and eight clinical studies were identified. The preclinical evidence demonstrates that the modulation of androgen receptor-related pathways has the potential to interfere with the activity of the Bacillus Calmette Guerin, doxorubicin, cisplatin, gemcitabine, and radiotherapy. The relative risk of BCa recurrence after transurethral resection of the bladder tumour (TURBT) is significantly lower in patients undergoing therapy with 5 alpha reductase inhibitors (5-ARIs) or androgen deprivation therapy (ADT) (Relative risk: 0.50, 95% CI: 0.30–0.82; p = 0.006). Subgroup analysis in patients receiving 5-ARIs revealed a relative risk of BCa recurrence of 0.46 (95% CI: 0.22–0.95; p = 0.040). A significant negative association between the ratio of T1 BCa patients in treated/control groups and the relative risk of BCa recurrence was observed. Therapy with 5-ARIs may represent a potential strategy aimed at reducing BCa recurrence rate, mainly in patients with low stage disease. Further studies are needed to confirm these preliminary data.

The Use of 5-Alpha Reductase Inhibitors and Alpha-1 Blockers Does Not Improve Clinical Outcome in Male Patients Undergoing Radical Cystectomy for Bladder Cancer in Quebec, Canada

BACKGROUND

Existing literature suggests that bladder cancer (BC) outcome may be improved when patients use 5α-reductase inhibitors and/or α₁-blockers, but such a conclusion may be subject to publication bias. We evaluated whether preoperative use of 5α-reductase inhibitors or α₁-blockers was associated with improved clinical outcomes in a cohort of patients with BC undergoing radical cystectomy (RC).

PATIENTS AND METHODS

Using provincial health administrative databases, we retrospectively identified male BC patients undergoing RC in Quebec province between 2000 and 2015, and we collected data from 2 years before RC until December 2016 or death. Survival analyses were conducted using Kaplan-Meier curves, log-rank tests, propensity score matching, and uni- and multivariable Cox proportional hazards models. Covariates included age, Charlson's comorbidity index, region of residence, year of RC, distance to hospital, hospital type, annual RC volume of each hospital and surgeon, neoadjuvant chemotherapy use, and type of bladder diversion.

RESULTS

Of the 2822 patients included, 284 patients used 5α-reductase inhibitors and 1001 patients used α₁-blockers prior to surgery. Median follow-up time was 7.7 years. Patients who used 5α-reductase inhibitors or α₁-blockers were generally older, had more comorbidities, and were treated more recently in academic centers. Overall, bladder cancer-specific and recurrence-free survival did not differ significantly between those using 5α-reductase inhibitors prior to surgery and controls who never used 5α-reductase inhibitors. Adjusted hazard ratios were 1.03 (95% confidence interval [CI], 0.88-1.21) for overall survival, 1.12 (95% CI, 0.92-1.36) for bladder cancer-specific survival, and 1.19 (95% CI, 0.99-1.42) for recurrence-free survival. The aforementioned outcomes were significantly worse in patients who used α1-blockers prior to surgery compared to controls, with respective adjusted hazard ratios of 1.15 (95% CI, 1.04-1.27), 1.19 (95% CI, 1.05-1.35), and 1.18 (95% CI, 1.05-1.33).

CONCLUSION

Preoperative use of 5α-reductase inhibitors and α₁-blockers did not improve clinical outcome in our cohort of male patients undergoing radical cystectomy for bladder cancer.