Understanding Patient Characteristics, Treatment Patterns, and Clinical Outcomes for Advanced and Recurrent Endometrial Cancer in Alberta, Canada.

e17624 Background: Endometrial cancer (EC) incidence in Canada is steadily increasing and a paucity of real-world data exists. This study aimed to examine treatment (tx) patterns and clinical outcomes for patients (pts) with advanced and recurrent (A/R) EC in Canada. Methods: A retrospective observational cohort study was conducted among pts with primary advanced EC (de novo stage IIIB, IIIC, IV) or recurrent EC (progression from de novo stage I, II, IIIA) between 2010 and 2018 in Alberta, Canada. Health administrative data were used to describe baseline characteristics, time to next tx (TTNT), and overall survival (OS). Using Kaplan-Meier methods, TTNT was defined from tx initiation to initiation of subsequent tx or death from any cause, and OS was examined from tx initiation until death from any cause. Outcomes were stratified by pt type (A/R) and tx. Results: 1,053 pts were included: 620 (58.9%) advanced and 433 (41.1%) recurrent pts. 713 (67.7%) pts received first-line (1L) systemic therapy; this differed by pt type (75.2% of advanced and 57.0% of recurrent pts). Advanced pts who received chemotherapy were more likely to have prior surgery (p < 0.001), radiotherapy (p = 0.01), were younger (p < 0.001), and had fewer comorbidities (p < 0.001) than those without chemotherapy. Platinum-based chemotherapy (PBCT) was the most common 1L regimen (78.6%), differing by pt type (96.1% for advanced and 45.4% for recurrent pts). Hormone therapy in 1L was higher for recurrent compared to advanced pts (27.9% vs 3.2%). Median TTNT and OS from 1L systemic therapy was 19.9 months (95% confidence interval [CI]: 17.5–23.5) and 35.9 months (95% CI: 31.5–53.5), differing by therapy (p < 0.05). Median OS from 1L ranged from 8.5 months (95% CI: 6.2–20.0; platinum monotherapy) to 62.5 months (95% CI: 59.2–NA; hormone therapy). 257 pts received second-line (2L) chemotherapy, with a median TTNT of 7.0 months (95% CI: 6.1–8.2) and median OS of 12.6 months (95% CI: 10.0–14.6). Outcomes differed by tx (p < 0.05), with median OS ranging from 8.0 months (95% CI: 5.9–13.2; non-platinum monotherapy) to 17.1 months (95% CI: 12.7–NA; non-platinum combination). Among pts who received a 1L PBCT, median OS from 2L chemotherapy (N = 187) was 10.4 months (95% CI: 8.9–13.3) and was significantly higher for those rechallenged with PBCT compared to no rechallenge (13.3 months [95% CI: 11.2–20.9] vs 6.4 months [95% CI: 4.6–10.4]). Median OS in third-line (N = 71) and fourth-line (N = 26) chemotherapy was 11.0 months (95% CI: 8.2–13.5) and 12.0 months (95% CI: 7.5–NA), respectively. Outcomes did not differ significantly by pt type (A/R; p≥0.05). Conclusions: Outcomes for pts with A/R EC in Alberta, Canada are poor, particularly following 1L therapy where tx options are limited. Novel therapies with proven efficacy could address this unmet need and improve pt outcomes. Funding: GSK (216962; diana.d.martins@gsk.com).