Multiplex screening of 422 candidate serum biomarkers in bladder cancer patients identifies syndecan-1 and macrophage colonystimulating factor 1 as prognostic indicators

Urothelial bladder cancer (UBC) is the 9th most common cancer world-wide (1). Approximately three-quarters of new cases present as non-muscle invasive disease (NMIBC) and the remainder present as muscle-invasive disease (MIBC). MIBC is life-threatening and patients require radical treatment with chemotherapy followed by cystectomy or radiotherapy (2). NMIBC patients are stratified into low-, intermediate- and high-risk groups according to clinicopathological parameters and are treated accordingly: transurethral resection (TUR) and intravesical mitomycin C for low risk, and TUR and intravesical BCG for intermediate- and high-risk NMIBC (3). Radical cystectomy is also considered an option for high risk NMIBC. UBC is initially detected by flexible cystoscopy, and NMIBC patients are subjected to regular long-term surveillance with this burdensome procedure. Urine or serum biomarkers that could detect and characterise UBC non-invasively could improve management of bladder cancer patients in several ways, e.g.