The presence of blood cells in the urine is a sign of bladder cancer. Because aspirin blocks platelets from forming harmful blood clots, this drug can cause minor bleeding or worsen existing bleeding in the urinary tract. Research results in internal medicine journal This suggests that this may prompt clinicians to perform tests that reveal asymptomatic bladder tumors.
For the study, researchers analyzed information from 50,771 Danish adults who started taking aspirin from 2005 to 2023 and 156,191 who started non-aspirin nonsteroidal anti-inflammatory drugs (NSAIDs), which have less pronounced antiplatelet properties than aspirin.
Compared with adults in the general population who had never used aspirin or NSAIDs, aspirin initiates had more cystoscopy, a minimally invasive procedure that allows doctors to see inside the bladder and urethra through a lighted tube equipped with a camera. Cytology testing showed that modern aspirin initiators have similar rates of bladder cancer, but lower rates during the invasive phase compared with non-users. This suggests that those initiating aspirin therapy represent a patient population with a high incidence of bladder cancer, and that their higher cystoscopy rates reflect this and are clinically justified. The high rate of associated cystoscopies, combined with the low prevalence of invasive cancer stage at diagnosis, suggests that asymptomatic bladder cancer may not be concealed.
Although NSAID initiators underwent more cystoscopies than nonusers, the incidence of bladder cancer after cystoscopy was lower and the stage distribution was similar to that of nonusers. This suggests that the higher cystoscopy rate may not have been clinically justified.
We are very encouraged by this result. Clinical practice emphasizes the importance of addressing symptoms of bladder cancer in aspirin initiators. This finding may further impact the question of whether aspirin can prevent bladder cancer, as detection in trials with short-term follow-up may manifest as a higher incidence in aspirin-exposed cohorts. ”
Dr. Marlene Soth-Hansen, first author, Aarhus University
sauce:
Reference magazines:
Hansen, Mississippi; Others. (2026). Initiation of aspirin or nonsteroidal anti-inflammatory drugs and subsequent evaluation for bladder cancer. internal medicine journal. DOI: 10.1111/joim.70115. https://onlinelibrary.wiley.com/doi/10.1111/joim.70115
