Aspirin or non-steroidal anti-inflammatory drug initiation and subsequent bladder cancer evaluation

Sep 23, 2026

Uploaded by Aldword

Evaluating whether starting aspirin or non-aspirin non-steroidal anti-inflammatory drugs (NSAIDs) reveals previously undiagnosed bladder cancers, the study compares initiators with matched never-users using Danish population-based registries. Among 50,771 aspirin initiators and 156,191 NSAID initiators, cystoscopy risk within 1 year after initiation was higher for both groups versus never-users, with adjusted hazard ratios around 1.54–1.56. Bladder cancer prevalence at cystoscopy and invasive-stage prevalence ratios differed by drug class, suggesting unmasking with aspirin but not with NSAIDs.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages11

Reading Time28 min

AccessFree to download

Background

Objectives

Methods

Results

Cystoscopy incidence and follow-up outcomes

Bladder cancer prevalence and invasive stage

Conclusion

| | |
Original Article | | --- | --- | --- | doi: 10.1111/joim.70115 Aspirin or non-steroidal anti-inﬂammatory drug initiation and subsequent bladder cancer evaluation Malene Söth Hansen 1,2 , Lars Dyrskjøt2,3 , Uffe Heide-Jørgensen 1,2 , Jørgen Bjerggaard Jensen2,4 & Mette Nørgaard 1,2 From the 1 Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark; 2 Department of Clinical Medicine, Aarhus University, Aarhus, Denmark; 3 Department of Molecular Medicine, Aarhus University Hospital, Aarhus, Denmark; and 4Department of Urology, Aarhus University Hospital, Aarhus, Denmark | Abstract. Hansen MS, Dyrskjøt L, Heide-Jørgensen U, Jensen JB, Nørgaard M. Aspirin or non-steroidal | Results. Among 50,771 aspirin initiators (median age: 67 years, 51% men) and 156,191 NSAID ini- | | --- | --- | | anti-inﬂammatory drug initiation and subsequent | tiators (age: 45 years, 50% men) adjusted haz- | | bladder cancer evaluation. J Intern Med. 2026;300: 193–203. | ard ratios of cystoscopy were 1.54 (95% conﬁdence interval [CI]: 1.38–1.72) and 1.56 (95% CI: 1.43–1.70) compared with never-users. Cystoscopy | | Background. Whether aspirin or non-aspirin nonsteroidal anti-inﬂammatory drugs (NSAIDs) initiation may unmask unknown bladder cancers (BCs) | recipients included 683 aspirin (age: 70 years, 69% men) and 1414 NSAID initiators (age: 60 years, 63% men); standardized morbidity ratio weighted | | by hematuria remains controversial. | (SMRW) prevalence ratios were 0.97 (95% CI, 0.76– 1.22) and 0.65 (95% CI, 0.51–0.82) compared with | | Objectives. To evaluate unmasking, we compared cystoscopy rates, BC prevalence at cystoscopy, and invasive stage prevalence at diagnosis in aspirin or | never-users. The SMRW invasive stage prevalence ratios were 0.81 (95% CI, 0.63–1.03) and 1.07 (95% CI, 0.85–1.34) in the aspirin and NSAID compari- | | NSAID initiators with never-users. | son. | | Methods. Using the Danish population-based registries, we identiﬁed all new aspirin or NSAID users in 2005–2023 and a matched never-using comparison cohort. Second, we identiﬁed all ﬁrst-time cystoscopy recipients in 2005–2022 with aspirin or NSAID initiation within 1 year prior or never- | Conclusion. The combination of more cystoscopies and a lower prevalence of invasive stage at BC diagnosis may suggest the unmasking of asymptomatic BC in aspirin initiators. We did not ﬁnd indications of unmasking with NSAID initiation. | | use in 10 years preceding cystoscopy. Comparing | Keywords: aspirin, bladder cancer, cancer early | | these groups, we computed hazard ratios of cystoscopy during 1-year follow-up, prevalence ratios | diagnosis, cystoscopy, NSAID | | of BC at cystoscopy, and invasive stage disease at | Abbreviations: NSAID, non-aspirin, non-steroidal, | | diagnosis. | anti-inﬂammatory drug; COX, cyclooxygenase enzyme; CCI, Charlson comorbidity index; SMR, standardized morbidity ratio | Background Bladder cancer (BC) is among the 10 most common cancers globally [1], accounting for 573,000 new diagnoses annually [2] . The most signiﬁcant clinical presentation is monosymptomatic macroscopic hematuria [3], justifying evaluation in Denmark [4] . Antithrombotic medication-induced hematuria has been suggested to reduce diagnostic delay of undiagnosed BC (unmasking) [5] . Aspirin is an antiplatelet medication through cyclooxygenase (COX)-1inhibition [6], however, only weakly associated with hematuria [7, 8] . Whether aspirin unmasks undiagnosed BCs is only sparsely addressed in the existing literature. A © 2026 The Author(s) . Journal of Internal Medicine published by John Wiley & Sons Ltd on behalf of Association for Publication of The Journal of Internal Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. 193 | | |
Aspirin/NSAID initiation and cystoscop

FAQs

What is the main question of this study?

Whether initiating aspirin or non-aspirin NSAIDs can unmask previously undiagnosed bladder cancers, compared with never-users.

How were outcomes assessed?

Using Danish registries, the study identified new aspirin or NSAID users (2005–2023) and a matched never-using cohort, then evaluated first-time cystoscopy recipients and subsequent bladder cancer findings.

What did the study find about cystoscopy rates?

Both aspirin and NSAID initiators had more cystoscopies than never-users during 1-year follow-up, with adjusted hazard ratios around 1.54–1.56.

Did the results support unmasking for both drug types?

The pattern suggested unmasking with aspirin, indicated by more cystoscopies and a lower prevalence of invasive stage at diagnosis. The study did not find indications of unmasking with NSAID initiation.

Sep 23, 2026

Uploaded by Aldword