Sexual dimorphism in bladder cancer: a review of etiology, biology, diagnosis, and outcomes

Bladder carcinoma represents a prevalent malignancy, wherein the influence of sex extends across its incidence, biological attributes, and clinical outcomes. This scholarly exposition meticulously examines pertinent investigations, elucidating the nuanced impact of sex on bladder cancer, and posits cogent avenues for future research and intervention modalities. In the initial discourse, an exhaustive scrutiny is undertaken of the etiological underpinnings of bladder cancer, encompassing variables such as tobacco consumption, occupational exposures, and genetic aberrations. Subsequently, a comprehensive dissection unfolds, delving into the intricate biological disparities inherent in sex vis-à-vis the initiation and progression of bladder cancer. This analytical framework embraces multifaceted considerations, spanning sex hormones, sex chromosomal dynamics, metabolic enzymatic cascades, and the intricate interplay with the microbiome. Lastly, a synthesized exposition encapsulates the ramifications of gender differentials on the diagnostic and prognostic landscapes of bladder cancer, underscoring the imperative for intensified investigative endeavors directed towards elucidating gender-specific variances and the formulation of tailored therapeutic strategies.

Analysis of sex-based differences to Bacillus Calmette-Guérin for non-muscle invasive bladder cancer

OBJECTIVE

To evaluate whether differences exist between men and women in response to intravesical BCG treatments. The incidence of urothelial carcinoma of the bladder is lower in women but they tend to present with more aggressive and advanced disease. Some prior studies also suggest there are sex-based differences in response to treatment for non-muscle invasive bladder tumors.

METHODS

In this retrospective study, we reviewed all consecutive patients who received BCG at the CHU de Québec - Laval University from 2009-2019. Men and women were treated with intravesical BCG therapy following pathologic confirmation of urothelial carcinoma. Outcomes evaluated include recurrence, progression, and treatment tolerability. Recurrence was defined as a pathology confirmed cancer whereas progression was the new development of high-grade (recurrence) pathology or an increase of stage. Tolerability was defined according to the proportion of prescribed BCG received. All clinical details were obtained through review of the medical records, collaborated by pharmacy records for BCG administration. Competing-risk analysis was used to compare outcomes.

RESULTS

Among 613 patients who received BCG at our institution between 2009-2019, 472 (77.0%) were men and 141 (23.0%) were women. The recurrence rate was not different between sexes, with a 5-year recurrence risk of 52% (95% CI: 36.93-65.4) among women compared to 57.5% (CI 95%: 51.9-62.6) among men. The overall non-progression rate at 1,3 and 5 years was 97.3% (95% CI: 95.6%-98.3%), 93.6% (95% CI: 91.2%-95.4%), and 91.7% (95% CI: 88.4%-94.1%), respectively. The completion of ≥5 induction BCG instillations and maintenance BCG use was similar in both genders.

CONCLUSIONS

We report a contemporary NMIBC cohort treated with BCG and find no clear evidence for sex-based differences in response to BCG treatment in regard of progression, recurrence, and tolerability.

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.

Predictive factors for progression of patients with carcinoma in situ of the bladder at long-term follow-up: pure versus non-pure CIS

BACKGROUND

The aim of this study was to identify the predictive factors for progression defined as any event that shifted the management of the disease from a bladder sparing approach, by comparing patients with pure versus non-pure carcinoma in situ (CIS) of the bladder.

METHODS

A retrospective analysis was carried out in consecutive patients affected by newly-diagnosed pure CIS and non-pure CIS (excluding cases with concomitant muscle invasive cancer). All patients were enrolled a in our institution from 1998 to 2010. Data was prospectively collected. Main end point was progression-free survival.

RESULTS

Overall, 149 patients with CIS were identified for the analysis. A total of 98 patients had pure CIS (66%). Median follow-up was 103 months (range: 40-206 months). Progression occurred in 29 patients (19%). A total of 30 patients died during the follow-up (20%). In 13 cases (9%), the death was cancer specific. Progression-free survival estimate was 181 months (95% CI: 169-193 months) and 154 months (95% CI: 133-176 months) respectively for pure and non-pure CIS population (P=0.03). Among examined variables (age, gender, symptoms, smoking habit, ASA score, number of bacillus Calmette-Guérin [BCG] instillations), multivariate analysis disclosed that only CIS type was an independent predictor of progression (P=0.03) with a relative risk of 0.37 in favor of pure CIS.

CONCLUSIONS

Pure and non-pure CIS are efficiently treated by BCG therapy combined with trans-urethral resection and/or radical cystectomy, with relatively low rate of progression. CIS type was the only significant predictor of progression.

Causes of death in long-term bladder cancer survivors: A population-based study

BACKGROUND

Long-term (> 5 years) bladder cancer survivors represent a distinct subgroup of bladder cancer patients and information about the causes of death in this subgroup is limited. The aim of this study was to review the causes of death in long-term bladder cancer survivors.

METHOD

The Surveillance, epidemiology and end results (SEER) database was used to analyze the causes of death of long-term bladder cancer survivors. Patients' characteristics and survival outcomes were reported for the entire cohort in our study. Kaplan-Meier analysis and Cox proportional hazard model for survival analysis.

RESULTS

A total of 147 781 bladder cancer patients with >5 years survival were identified. This cohort included 81 843 patients surviving 5-10 years and 65 938 patients surviving >10 years. Among the patients who survived 5-10 years, 6.9% died because of primary bladder cancer, 11.0% due to cardiac disease and 7.7% due to nonmalignant pulmonary disease. Among patients surviving >10 years, 3.1% died because of primary bladder cancer, 8.6% due to cardiac disease and 5.8% due to nonmalignant pulmonary disease. On multivariate analysis, factors associated with longer cardiac disease-specific survival among long-term bladder cancer survivors include younger age at diagnosis（<40 years; vs. 40-69 years, P = 0.030 or >69 years, P < 0.001), married status (vs. single status, P < 0.001), white race (vs. African American race, P = 0.002), male (vs. female, P < 0.001), grade I (vs. grade III, P = 0.003 or grade IV, P < 0.001).

CONCLUSION

The probability of death from primary bladder cancer is still important among various causes of death even 20 years after being diagnosed with bladder cancer. Furthermore, cardiopulmonary causes contributed to a considerable proportion of deaths in long-term bladder cancer survivors.

Review on gender differences in non-muscle invasive bladder cancer

Differences in the epidemiology, diagnosis and outcomes according to gender in patients diagnosed with non-muscle invasive bladder cancer (NMIBC) has been widely reported. In this article we present gender-specific differences in NMIBC in terms of epidemiology, risk factors, first clinical presentation, management and clinical outcomes based on systematically review evidence of existing literature. A literature search of English-language publications that included an analysis of the association of gender differences in patients with NMIBC was performed using PubMed. Sixty-four studies were selected for analysis with consensus of all authors. The incidence and mortality for urothelial bladder cancer (UBC) are higher in men, whereas cancer specific mortality to incidence ratio is significantly lower for men than for women. This phenomenon could be partially explained by differences in exposure to bladder cancer carcinogens. However female gender is associated with higher stage at presentation. Thirteen studies with a total of 11,069 patients diagnosed with NMIBC were included for analysis according to outcomes. In studies that found statistically significant differences in outcomes between sexes, female gender was reported as risk factor for disease recurrence, progression or cancer specific mortality. None of included studies found worse outcomes in men when compared to women with NMIBC. Results of our review suggest that female gender in patients diagnosed with NMIBC is associated—though inconsistently—with higher stage at presentation and poorer outcomes. Numerous factors may influence gender gap in incidence rate, clinical management and reported outcomes. Consensus on comparable data collection in routine practice and prospective trials including clinical outcomes are required to identify gender-specific differences in patients diagnosed with NMIBC.

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.