LAUSR

417Background: High endothelial venules (HEVs) are present in lymph nodes and tertiary lymphoid organs. It has been reported that low HEV density is associated with the poor prognosis of several carcinomas. MECA-79 antibody recognizes L-selectin ligand (6-sulfosialyl Lewis X glycan) expressed in HEV. In the present study, we examined whether MECA-79 positive HEV density was associated with clinical outcomes of patients with upper tract urothelial carcinoma (UTUC) treated with radical nephroureterectomy (RNU). Methods: Eighty-eight patients with UTUC who underwent RNU at the Hirosaki University hospital between January 2008 and December 2016 were enrolled. Tissue microarray for MECA-79 was performed, and HEV densities were calculated. HEV density < 1.5/mm2 was defined as HEV (−); HEV density ≥1.5/mm2 was defined as HEV(+). Results: Of 88 patients, 64 (72.7%) were male and 24 (27.2%) were female. The average age was 68.5 years (range, 36–84 years). Fifty-three patients (60.2%) had previously undergone neoad...