Five-alpha-reductase expression in benign and malignant urothelium: Correlation with disease characteristics and outcome

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).

Gender discrepancies in bladder cancer: potential explanations

INTRODUCTION

Gender differences in urothelial carcinoma of the bladder (UCB) exist. Although men have a higher incidence of UCB, women tend to have poorer outcomes. We have explored and summarized the evidence for gender differences of UCB diagnosis and prognosis, together with reasons for these disparities.

AREAS COVERED

The incidence of UCB is 3-4 times higher in men than women. However, women are more likely to be diagnosed with advanced disease. Women have a higher stage-for-stage mortality compared to men, and their greatest risk of death appears to be within the first 2 years of diagnosis. Survival outcomes following radical cystectomy (RC) and radiotherapy are also poorer in women. Delays in diagnosis, differences in female anatomy, as well as poorer surgical outcomes post-RC appear to contribute significantly to the disparities noted between genders. Other factors such as exposure to risk factors, differential hormone signaling, and carcinogen breakdown may also have a role.

EXPERT OPINION

The gender divide in UCB outcomes has to be addressed. Improved medical and patient education and centralization of RC are recommended.

Suppressed Recurrent Bladder Cancer after Androgen Suppression with Androgen Deprivation Therapy or 5α-Reductase Inhibitor

PURPOSE

We determined whether intravesical recurrence is affected by inhibition of androgen signaling among men with nonmuscle invasive bladder cancer.

MATERIALS AND METHODS

We examined the intravesical recurrence rate among men treated with or without androgen suppression therapy by androgen deprivation therapy for prostate cancer or 5α-reductase inhibitor dutasteride for benign prostatic hyperplasia.

RESULTS

We studied 228 men, including 32 with and 196 without androgen suppression therapy. During a median followup of 3.6 and 3.0 years intravesical recurrence developed in 4 (12.5%) and 59 men (30.1%) with and without androgen suppression therapy, respectively. On multivariate analysis multiple tumors (HR 1.82, p = 0.027), a large tumor (HR 2.13, p = 0.043) and ever smoking (HR 2.45, p = 0.020) as well as the presence of androgen suppression therapy (HR 0.36, p = 0.024) were independent risk factors for intravesical recurrence. Notably, tumor progressed to muscle invasive bladder cancer in 6 men (3.1%) without androgen suppression therapy. No man with androgen suppression therapy progressed to muscle invasive bladder cancer.

CONCLUSIONS

Our study suggests the possibility of androgen suppression therapy as prophylaxis for intravesical recurrence of bladder cancer. Further explorations are warranted of the prophylactic effect of androgen suppression therapy on bladder cancer pathogenesis.

Association of Aromatase With Bladder Cancer Stage and Long-Term Survival: New Insights Into the Hormonal Paradigm in Bladder Cancer

BACKGROUND

Hormonal factors may play a role in bladder cancer (BCa). We investigated the expression of aromatase and estrogen receptor (ER)β and its association with pathological variables and survival outcomes.

PATIENTS AND METHODS

BCa specimens from 40 patients were evaluated. Immunohistochemistry was performed for aromatase and ERβ. Descriptive statistics and univariate analyses assessed the association of these markers with pathologic variables and survival outcomes.

RESULTS

Aromatase expression was significantly associated with tumor stage; muscle-invasive disease was found in 15 of 19 (79%) patients with positive staining and in 7 of 18 (39%) patients with negative staining (P = .02). Node-positive disease was found in 8 of 19 (42%) patients with positive staining and 1 of 18 (6%) patients with negative staining (P = .01). After a median follow-up of 112 months, Cox regression analysis demonstrated that aromatase expression was associated with a more than 2-fold risk of cancer recurrence (hazard ratio, 2.37; confidence interval, 0.92-6.08; P = .07) and an almost 4-fold higher risk of cancer-specific death (hazard ratio, 3.66; 95% confidence interval, 1.19-12.06; P = .02). Muscle-invasive disease was found in 15 of 18 (83%) ERβ-positive specimens and 4 of 12 (33%) ERβ-negative specimens (P = .0009). Hierarchical clustering analysis demonstrated a 4-fold up-regulation of ERβ gene expression in tumor versus adjacent, non-tumor urothelium (P < .05). However, no significant association with survival outcomes was found.

CONCLUSION

Aromatase expression in BCa may be associated with advanced tumor stage and poorer survival outcomes. ERβ is upregulated in malignant tissue, and its expression is associated with muscle-invasive disease. These findings provide further evidence for the hormonal paradigm in BCa.

Gender and Bladder Cancer: A Collaborative Review of Etiology, Biology, and Outcomes

CONTEXT

The incidence of bladder cancer is three to four times greater in men than in women. However, women are diagnosed with more advanced disease at presentation and have less favorable outcomes after treatment.

OBJECTIVE

To review the literature on potential biologic mechanisms underlying differential gender risk for bladder cancer, and evidence regarding gender disparities in bladder cancer presentation, management, and outcomes.

EVIDENCE ACQUISITION

A literature search of English-language publications that included an analysis of the association of gender with bladder cancer was performed using Pubmed. Ninety-seven articles were selected for analysis with the consensus of all authors.

EVIDENCE SYNTHESIS

It has been shown that the gender difference in bladder cancer incidence is independent of differences in exposure risk, including smoking status. Potential molecular mechanisms include disparate metabolism of carcinogens by hepatic enzymes between men and women, resulting in differential exposure of the urothelium to carcinogens. In addition, the activity of the sex steroid hormone pathway may play a role in bladder cancer development, with demonstration that both androgens and estrogens have biologic effects in bladder cancer in vitro and in vivo. Importantly, gender differences exist in the timeliness and completeness of hematuria evaluation, with women experiencing a significantly greater delay in urologic referral and undergoing guideline-concordant imaging less frequently. Correspondingly, women have more advanced tumors at the time of bladder cancer diagnosis. Interestingly, higher cancer-specific mortality has been noted among women even after adjusting for tumor stage and treatment modality.

CONCLUSIONS

Numerous potential biologic and epidemiologic factors probably underlie the gender differences observed for bladder cancer incidence, stage at diagnosis, and outcomes. Continued evaluation to define clinical applications for manipulation of the sex steroid pathway and to improve the standardization of hematuria evaluation in women may improve future patient outcomes and reduce these disparities.

PATIENT SUMMARY

We describe the scientific basis and clinical evidence to explain the greater incidence of bladder cancer in men and the adverse presentation and outcomes for this disease in women. We identify goals for improving patient survival and reducing gender disparities in bladder cancer.