Ovarian cancer in adolescents and young adults compared with older women: Prognostic factors, demographic characteristics, and survival along 2 decades in the US.

e17571 Background: Globally, among Adolescents and Young Adults (AYA) Ovarian Cancer (OC) has the #1 incidence and mortality in female cancers (Huang 2024). Treatment selection is driven by stage and histology (Triarico 2022) and is unchanged for >20 years in some histologies (Travis 2023). Tailored approach based on sociodemographics and histology is recommended (Triarico 2022) but their frequency have not been published recently. Our objective is to describe clinical characteristics, prognostic factors and survival in AYA-OC in the US. Methods: Cases of OC with C56.9 diagnosis in SEER Database 2000-2021 were obtained. AYA age was defined by NCI. Statistics were done with SPSS, comparing characteristics with Chi-squared test, obtaining median OS with Kaplan-Meier method and identifying independent prognostic factors for OS with Cox Regression. A p-value ≤0.05 was considered statistically significant. Results: 99,989 women ≥15 years of age were included. Median age: 62 years (IQR: 22). 8,182 AYA cases (8.2%) were found. The median OS was not reached for AYA, with a 5-year OS of 80%; for older women it was 41% (p<0.001). The median OS for older women it was 40 months (95%CI: 39.4-40.6). AYA vs older women comparison results: lower frequency of Stage IV (28.6% vs 61.5%, p<0.001), higher frequency of Germ cell type (28.1% vs 0.8%, p<0.001), lower proportion of Non Hispanic White (NIW; 48.2% vs 70.5%, p<0.001). When standardized by stage, surgery was given more frequently in AYA with metastatic disease vs olders (87.2% vs 69%, p<0.001) and also chemotherapy (83.6% vs 75.2%, p<0.001). Age is an independent prognostic factor for survival (HR=0.46, 95%CI: 0.44–0.49) in favor of AYA, in all population analysis. The subanalysis for AYA population found that metastatic disease (HR=6.69, p<0.001), mucinous type (HR=3.46, p<0.001) and clear cell type (HR=3.5, p<0.001) faced poorer OS. Comparison with NIW showed that Non-Hispanic Blacks (NIB; HR=1.36, p<0.001), Non-Hispanic Asian/Pacific (HR=1.27, p=0.005) and Hispanics (HR=1.14, p=0.049) faced poorer outcomes. For adults only, the same poor prognosis was found for NIB, but for other races better survival was found (HR<1, p<0.001). Surgery survival benefit was seen in adults (HR=0.52, p<0.001) but no impact in AYA (p=0.640). Chemotherapy improved OS in older women (HR=0.58, p<0.001) but for AYA (HR=1.42, 95%CI:1.24-1.63), with a sub-analysis by histology showing it except for germ cell tumor and the carcinomas: clear cell, endometrioid, squamous and Brenner; where no impact on survival was found (p>0.05). Conclusions: Our study adds new information on survival for AYA vs older women, racial differences, and outcomes for same histologies based on age, that could be explained by menopausal status (not explored in our research). Limitations also include lack of genetics and AYA sample size. It has been proposed molecular stratification, clinical characteristics and histopatology to stratify patients in clinical trials (Travis 2023) and our study contributes for planning future trials in AYA-OC.