Trends in non-epithelial ovarian malignancies in patients younger than 51 from 2004 to 2022 in the United States.

Abstract

e17554 Background: Non-epithelial ovarian cancers (NOCs) are rare but disproportionately affect younger patients (pts), where diagnosis delays can limit fertility-preserving options or result in early menopause. With increasing cancer rates in younger pts, trends in NOC case volume and stage at presentation remain poorly defined. Therefore, the objective of this study was to examine national trends of NOC in pts under 51 years of age from 2004 to 2022 in the United States. Methods: Pts diagnosed with NOC between 2004 and 2022 under the age of 51 were identified using the National Cancer Database. Demographic and clinicopathologic variables were collected. Trends in incidence were evaluated by year of diagnosis and stratified by age group, stage, and histology. Comparisons across groups were performed using Pearson Chi-Square tests with likelihood ratio Chi-Square also reported when appropriate. Temporal trends over time were assessed using linear-by-linear association. Statistical significance was defined as p<0.05. Results: Between 2004 and 2022, a total of 6,863 pts were diagnosed with NOC, including 4,078 (59.4%) germ cell tumors (GCT), 2,687 (39.2%) sex-cord stromal tumors (STC), and 98 (1.4%) ovarian sarcomas. The number of pts diagnosed with NOC increased by 72% during the study period, rising from 257 pts in 2004 to 442 pts in 2022 (p<0.001). Overall, 4,622 (67.3%) pts were diagnosed with stage I, 595 (8.7%) pts with stage II, 1,271 (18.5%) with stage III, and 375 (5.5%) stage IV. During the study period, while the number of GCT remained stable, the number of STC nearly tripled (from 86 pts diagnosed in 2004 to 243 in 2022) and the number of pts diagnosed with ovarian sarcoma substantially increased (1 in 2004 to 12 in 2022)( p<0.001). The rise in new diagnoses was driven largely by older pts, with the 35–44 age group increasing from 22.6% to 32.8% and with the 45–51 age group increasing from 15.6% to 19% between 2004 and 2022 (p<0.001). In terms of stage, pts were more likely to be diagnosed with stage IV if they were diagnosed later in our study period (4.2% vs 6.4%, p<0.001) and less likely to be diagnosed with stage I (69.1% vs 66%, p<0.001). Conclusions: In our young pt cohort, NOCs have rising national case volume, driven mainly by increasing SCSTs and a relative increase in ovarian sarcomas. The shift toward older age and more advanced stage at diagnosis suggests delayed recognition and fewer opportunities to prevent treatment-induced menopause. These trends underscore the need to streamline evaluation and referral to specialty centers, improve NOC-specific symptom recognition, and expand registries and trial networks to better address a growing burden of rare ovarian cancers in younger pts.