Introduction:

The association between socioeconomic status and oncological outcomes has been described, highlighting their influence on stage at presentation, treatment patterns, and overall mortality. Nevertheless, the specific impact of socioeconomic marginalization on non-muscle invasive bladder cancer (NMIBC) outcomes remains uncertain. The Ontario Marginalization Index (ON-Marg) serves as a comprehensive tool to explore health inequality through four dimensions: residential instability, material deprivation, dependency, and ethnic concentration. This study aims to investigate the association between marginalization and NMIBC outcomes among patients treated at both community and academic centers in Ontario, a region characterized by one of the world's most diverse communities and supported by a publicly funded health care system.

Methods:

A retrospective chart review and analysis of 2794 patients diagnosed with NMIBC between 2005 and 2022 was conducted. Data on marginalization status, clinical and disease characteristics, treatment compliance, and oncological outcomes such as recurrence, progression, and survival were collected. Marginalization status was determined using the ON-Marg and categorized into quintiles, with higher numbers representing a greater degree of marginalization. Differences in tumor stage at diagnosis and treatment compliance were assessed using Chi-squared tests. Time-to-event analysis were assessed by Kaplan-Meier curve analysis.

Results:

Patient characteristics, stratified by marginalization quintile, are summarized in Table 1. Median follow-up was 5.9 years (IQR 3.2-9.2). At diagnosis, poorer marginalization status was associated with significantly higher tumour grade (p=0.024). Patients with worse marginalization status were also less likely to receive BCG treatment when indicated (p=0.023). The overall recurrence rate was 53.6%, with evidence of a progressive but not significant increase in the incidence of recurrence and a shorter time to recurrence from the least to the most marginalized quintiles. Worse marginalization status is associated with a progression to muscle-invasive disease and overall mortality (Figure 1). 

Conclusion:

Marginalized patients were more likely to present with higher grade tumours at diagnosis. Delayed presentation or other unmeasured factors may potentially contribute to this finding. Moreover, treatment compliance, especially use of BCG, was worse within more marginalized groups and may be associated with worse oncological outcomes, such as disease progression and overall mortality. The incorporation of socioeconomic status into clinical assessments can aid healthcare practitioners in identifying vulnerable patient populations and tailoring interventions to improve outcomes in NMIBC.

Funding: N/A