Article Impact Level: HIGH Data Quality: STRONG Summary of Journal of Internal Medicine https://doi.org/10.1111/joim.70115 Dr. Malene Söth Hansen et al.
Points
- Platelet inhibition from aspirin therapy can provoke minor urinary tract bleeding that prompts clinicians to perform diagnostic testing for asymptomatic bladder tumors.
- The extensive registry study tracked 50,771 Danish adults initiating aspirin and 156,191 individuals initiating non-aspirin non-steroidal anti-inflammatory drugs between 2005 and 2023.
- Patients starting aspirin underwent significantly more diagnostic cystoscopies and demonstrated a much lower prevalence of invasive-stage tumors at the time of cancer diagnosis.
- Individuals starting non-aspirin non-steroidal anti-inflammatory drugs also experienced elevated cystoscopy rates but showed a lower overall cancer prevalence and baseline stage distribution.
- The clinical data underline the importance of immediately investigating suspicious bladder symptoms or microhematuria in patients who have recently initiated an aspirin regimen.
Summary
The initiation of aspirin or non-aspirin non-steroidal anti-inflammatory drugs (NSAIDs) leads to the unmasking of asymptomatic bladder cancer (BC). Because aspirin possesses potent antiplatelet properties that block thrombus formation, it can provoke or exacerbate subclinical microhematuria within the urinary tract. The investigators sought to determine if this pharmacological effect prompts clinically warranted diagnostic evaluations, potentially catching localized malignancies before they advance to muscle-invasive stages.
Using data from Danish medical registries spanning 2005 to 2023, the study analyzed 50,771 adults initiating aspirin therapy and 156,191 adults initiating non-aspirin NSAIDs, comparing both cohorts to never-users in the general population. Aspirin initiators underwent a higher volume of diagnostic cystoscopies than never-users. Although the overall prevalence of bladder cancer remained similar upon diagnostic workup, the aspirin cohort presented with a significantly lower prevalence of advanced, invasive tumor stages at the time of diagnosis, indicating early-stage detection.
Conversely, while non-aspirin NSAID initiators also received more diagnostic cystoscopies than never-users, their subsequent post-procedure bladder cancer prevalence was lower, and their tumor stage distribution mirrored that of the unexposed population. This statistical variation suggests that elevated cystoscopy rates among NSAID users may lack definitive clinical justification. Ultimately, the findings indicate that starting aspirin therapy unmasks asymptomatic bladder cancer, justifying aggressive urological evaluation of hematuria in these patients and complicating short-term clinical trials evaluating aspirin as a chemopreventive agent.
Link to the article: https://onlinelibrary.wiley.com/doi/10.1111/joim.70115
References
Hansen, M. S., Dyrskjøt, L., Heide‐Jørgensen, U., Jensen, J. B., & Nørgaard, M. (2026). Aspirin or non‐steroidal anti‐inflammatory drug initiation and subsequent bladder cancer evaluation. Journal of Internal Medicine, joim.70115. https://doi.org/10.1111/joim.70115
