665 Background: Real-world data are needed to improve the understanding of the clinical management of la/mUC and associated outcomes. This study aimed to provide an overview of the la/mUC population, tx patterns, and overall survival (OS) in England. Methods: This retrospective cohort study used data from the national Cancer Analysis System (CAS) registry and included pts aged ≥18 years with de novo la/mUC diagnosed between 2014-2022, with follow-up through May 2024. Pts were split into 3 cohorts: systemic anticancer therapy (SACT)-untreated, SACT-treated (≤90 days post diagnosis), or delayed-SACT ( > 90 days). Descriptive statistics were used for all analyses. Median OS from diagnosis was estimated using the Kaplan-Meier method. Results: Of 15,526 eligible pts with la/mUC, 64.1% were in the SACT-untreated cohort, 21.9% in the SACT-treated, and 14.1% in the delayed-SACT. The proportion of pts receiving SACT increased from 32% diagnosed in 2014 to 40% diagnosed in 2022. Compared with SACT-treated and delayed-SACT pts, SACT-untreated pts were more likely to be older, female, more socioeconomically deprived, and have more comorbidities. Pt demographics and tumor characteristics are outlined in the Table. The median (IQR) time from la/mUC diagnosis to SACT initiation was 73 (48-132) days. Among SACT-untreated patients, 8% died in ≤30 days and 28% in ≤90 days of diagnosis, and 74.5% died overall during follow-up. Median OS in SACT-untreated pts was 6.6 months (95% CI, 3.3-6.8). In the SACT-treated cohort, 3,065 (90.4%) received first-line platinum-based chemotherapy. Of these, 1,564 (46.1%) received cisplatin/gemcitabine (split dose, 25.4%) and 1,243 (36.6%) carboplatin/gemcitabine. Only 26.8% received a second-line tx. Conclusions: A substantial number of pts ( > 78%) experienced delayed and low tx rates, despite a positive trend in tx rates over time. Measures are needed to address barriers to tx access, especially for the untreated la/mUC population in England; thus, attenuating its burden through timely tx. Cohorts Overall cohort SACT-untreated SACT-treated Delayed-SACT (N=15,526) (n=9,947) (n=3,392) (n=2,187) Age at diagnosis, y Mean (SD) 72 (10.9) 74.7 (10.5) 66.7 (10) 67.7 (9.8) Female n (%) 5,340 (34.4) 3,508 (35.3) 1,087 (32.1) 745 (34.1) Site, bladder n (%) 11123 (71.6) 7,329 (73.7) 2,499 (73.7) 1,295 (59.2) Stage IV n (%) 8,699 (56.0) 5,594 (56.2) 2,120 (62.5) 985 (45.0) Transitional cell histology n (%) 11,085 (71.4) 6,987 (70.2) 2,545 (75.0) 1,553 (71.0) Variant/mixed histology n (%) 4,441 (28.6) 2,960 (29.8) 847 (25.0) 634 (29.0) Index of multiple deprivation quintile Most deprived, n (%) 2,862 (18.4) 1,904 (19.1) 582 (17.2) 376 (17.2) … 3,193 (20.6) Least deprived, n (%) 2,012 (20.2) 734 (21.6) 447 (20.4) Charlson Comorbidity Index <jats:td colspan="1" ro
Stevenson et al. (2026) studied this question.