Overview

• BMJ Public Health published a national cohort analysis of Swedish registers from 1997–2018 covering 1.668 million men and 1.889 million women aged 50 and older, with 605,557 first diagnoses of acute cystitis.
• Cancer risk peaked within three months after infection, with bladder cancer nearly 34 times higher in men and 30 times higher in women, kidney cancer up to 11 times in men and nearly 8 times in women, and prostate cancer about 7 times higher before the excess disappeared by one year.
• Early excess translated to substantial short-term absolute increases, estimated at roughly 484 additional urogenital cancers per 10,000 person-years in men and about 96 in women during the first three months.
• Risks declined over time yet stayed elevated for several cancers, including bladder cancer at roughly 3.5 times higher in men and just over three times in women among those with a prior cystitis diagnosis.
• The authors suggest possibilities such as symptom overlap or occult disease and advise clinicians to treat cystitis in people over 50 as a possible marker, while noting that most UTIs are unrelated to cancer and generally resolve with routine care.