467 Background: Cisplatin-based neoadjuvant chemotherapy (NAC) followed by RR is the standard of care in cisplatin-eligible pts with MIUC. Adjuvant chemotherapy (AC) with cisplatin-based tx may be offered to those not given NAC. The unmet need this survey tried to evaluate is the post-RR burden of disease, quality of life (QoL) and perioperative tx patterns among MIUC pts. Methods: Real-world descriptive data were drawn from Adelphi’s MIUC Disease-Specific Programme: A point-in-time survey conducted with clinical/medical oncologists/urologists and their pts in 9 countries between January and June 2021. Physicians completed a survey on their pts’ clinical characteristics and tx patterns, while pts voluntarily completed a series of patient-reported outcome measures. Results: Of 2178 pts (data provided by 320 physicians), 30% received NAC only, 26% received AC only, 38% received no NAC or AC tx, and 6% received both. 1744 pts had initial tumour in the bladder; 35% received NAC only, 24% AC only, 35% no NAC or AC tx, and 6% received both. Of 387 pts with upper-tract urothelial carcinoma (UTUC), 51% received no NAC/AC tx, 35% received AC only, and 12% NAC only. More pts with T3 disease received no NAC/AC tx (36%) or NAC (35%) than AC (24%). Of 734 pts with nodal disease, 36% received NAC only. Of all pts, 60% experienced symptoms at data abstraction: 50% in pts who received NAC only, 71% in pts who received AC only and 82% in pts of those who received both. Pts reported similar EQ-5D-5L utility index scores (mean = 0.86; range: 0.84 [AC only] to 0.89 [NAC only]). Overall, feeling pain (40%) and stress (39%) were the EQ-5D domains with the worst scores. Pts who received AC only reported nominally lower EQ-5D visual analogue scale scores (71.11) compared with pts who received no NAC/AC (73.17) or pts who received NAC only (75.05). EORTC QLQ-C30 Global Health Status scores were 60.0 in pts who received AC only, 64.1 in pts who received NAC only or no NAC/AC, and 66.7 for pts who received both NAC and AC. Conclusions: Nearly 40% of pts remain untreated in either NAC or AC setting in 9 countries. A higher proportion of pts with UTUC go untreated. AC was more frequently used in UTUC vs BC pts; and in pts with Tis. NAC was implemented more frequently in pts T3 disease and in those with N+ disease. Pts who received AC appear to have nominally worse QOL and more symptoms, further demonstrating the need for efficacious adjuvant tx that does not decrease post-RR QoL.[Table: see text]