Evans blue as a selective dye marker for white-light diagnosis of non-muscle-invasive bladder cancer: an in vitro study.

Abstract

To develop a diagnostic method relying on the preferential accumulation of a dye in non-muscle-invasive bladder cancer (NMIBC) that is visible in conjunction with white-light cystoscopy (WLC). We investigated in detail the permeation of Evans blue in urothelial cell carcinoma (UCC) spheroids prepared from T24, J82 and RT-112 human cell lines and spheroids composed of normal human urothelial (NHU) cells. To gain more insight into the differential accumulation, all spheroids were investigated ultrastructurally using transmission electron microscopy (TEM). We found that, after exposure to Evans blue for 2 h, UCC spheroids accumulated dramatically more dye than spheroids composed of NHU cells. Using TEM it was found that the malignant spheroids contain similar ultrastructural characteristics, i.e. a wide intercellular space and a decreased number of desmosome-like cell attachments, to those from clinical samples of non-papillary carcinoma in situ of the bladder. We believe the present findings could be important for future developments in clinical diagnostics for early bladder cancer detection, staging and grading involving WLC.