Feasibility study of screening for bladder cancer with urinary molecular markers (the BLU-P project)

The prognosis of bladder cancer (BC) depends mainly on its histology, grade, and stage. Patients with superficial BC (70% of the urothelial carcinomas) have a relatively good prognosis, but patients diagnosed with invasive, high grade BC, and those who progress to invasive BC, have a poor prognosis and will not survive their disease in many cases due to their metastases, despite the currently available treatment options. Early detection can only be beneficial regarding mortality if the high risk cancers are recognized and treated at a localized stage.

Previous pilot studies on early detection consisted of home-based repeated hematuria testing and, in case of hematuria, a urologic evaluation with cytology and cystoscopy was carried out. This design resulted in too many cystoscopies. The recently initiated [Bladder Cancer Urine Marker Project (BLU-P) study www.blu-project.org] assesses the feasibility of a population-based screening for BC and at the same time evaluates a screening algorithm using next to hematuria testing, sensitive specific urine markers for BC (NMP22, FGFR3, MA analyses and MLPa) in an attempt to circumvent the high number of cystoscopies.

So far 1,611 men are included and 23.5% tested positive for hematuria (11.6% had one or more true positive test results). The additional molecular-based screening tests before referring to cystoscopy resulted in a decrease of the number of cystoscopies from 378 to 66 (82.5%). In those men referred for cystoscopy, so far only 1 BC case was detected.

Further research is needed to evaluate whether this extremely low detection rate is caused by, e.g., a healthy screenee bias or that the additional selection step using the molecular urine tests is too strict and diagnoses are missed.