The significance of isolated de novo red patches in the bladder in patients referred with suspected urinary tract cancer: Results from the IDENTIFY study.

Objectives: To assess the contemporary malignancy rate in isolated de novo red patches in the bladder and associated risk factors for better selection of red patch biopsy.

Patients: Patients from the IDENTIFY dataset; Patients referred to secondary care with suspected urinary tract cancer and found to have isolated de novo red patches on cystoscopy.

Methods: We reported the unadjusted cancer prevalence in isolated de novo red patches that were biopsied; multivariable logistic regression was used to explore cancer-associated risk factors including age, sex, smoking, type of haematuria, LUTS, UTIs and a suspicious-looking red patch (as reported by the cystoscopist). Sub-analysis of these by clinical role and experience was performed.

Results: A total of 1110 patients with isolated de novo red patches were included. 41.5% (n = 461) were biopsied, with a malignancy rate of 12.8% (59/461), which was significantly higher in suspicious versus non-suspicious red patches (19.1% vs. 2.81%, p < 0.01). There was a significant association between bladder cancer and age (OR 1.04, 95% CI 1.01-1.07, p = 0.01), smoking history (OR 2.62, 95% CI 1.09-6.27, p = 0.03) and suspicious-looking patch (OR 6.50, 95% CI 2.47-17.1, p < 0.01). The majority of malignancies were in over 60-year-olds. Malignancy rates in suspicious versus non-suspicious red patches did not differ significantly between clinical roles or experiences.Limitations included subjectivity in classifying a suspicious patch and selection bias as not all patches were biopsied.

Conclusions: Many patients still undergo unnecessary biopsies under general anaesthetic for isolated de novo red patches. Clinicians should consider the patient's age, smoking status and how suspicious-looking the patch is, before deciding on surveillance versus biopsy to improve cancer diagnostic yield.