This prospective multicenter observational study evaluates whether women ≥50 years with isolated acute hemorrhagic cystitis (AHC) and macroscopic hematuria require full malignancy workup. All participants undergo standard diagnostics (cystoscopy, CT urography, cytology), with 12-month follow-up for cancer detection. The aim is to identify low-risk patients where invasive investigations may be safely avoided.

The BLUSH trial is a prospective, multicenter, observational study investigating whether full malignancy workup is necessary in women ≥50 years presenting with isolated acute hemorrhagic cystitis (AHC) and macroscopic hematuria. AHC is defined as macroscopic hematuria accompanied by acute lower urinary tract symptoms (dysuria, frequency, urgency) of less than one week's duration. Women with prior urological malignancies, significant comorbidities, or impaired consent capacity are excluded.

All enrolled patients undergo standardized initial assessment including full clinical history (smoking, family history, comorbidities), physical examination, urinalysis, urine culture, cystoscopy, CT urography, and cytology when indicated. Participants are stratified into AHC and non-AHC groups based on symptomatology and laboratory findings. Data collection includes demographics, symptom duration, urine findings, cancer diagnoses (type, stage, grade), treatment details, and clinical outcomes.

Patients are followed for a minimum of 12 months via medical record review to capture delayed cancer diagnoses. Data are pseudonymized and stored securely under GDPR regulations. The primary outcome is the incidence of urological malignancy within one year. Secondary outcomes include time to diagnosis, proportion of avoidable invasive procedures, and accuracy of the AHC classification in predicting cancer risk.

The study aims to support individualized risk-based management in women with hematuria.

Inclusion Criteria:

1. Women ≥50 years of age.
2. Macroscopic hematuria.
3. Presenting for evaluation within the SCP for macroscopic hematuria.
4. Ability to provide informed consent.

Exclusion Criteria:

1. Prior diagnosis of bladder cancer, renal cancer, or upper tract urothelial carcinoma (UTUC).
2. Cognitive impairment preventing informed consent.
3. Ongoing or recent treatment for urological malignancy.
4. Serious comorbidities affecting participation or safety.
5. Pregnant women.

Eligibility is limited to individuals identifying as female, based on self-reported gender identity.

Women aged 50 years and older presenting with macroscopic hematuria. Participants are recruited at initial presentation within the standard care pathway for hematuria evaluation at participating centers in Sweden.

At this time, no final decision has been made regarding sharing of individual participant data (IPD). Any future sharing would require appropriate ethical approvals, participant consent, and compliance with data protection regulations.