An NCDB analysis on the demographic, treatment, and survival of seromucinous carcinoma.

e17538 Background: Seromucinous carcinoma (SMC) is a rare subtype of ovarian cancer composed predominantly of serous and endocervical-type mucinous epithelium. Fewer than 40 cases have been reported in the literature, with no stage IV cases to date. Documented cases of ovarian SMC showed a 5-year survival rate of less than 60%. Given the rarity of SMC, an investigation of socioeconomic and demographic factors using the National Cancer Database (NCDB) may provide an important perspective on its epidemiology. Methods: Data from the NCDB, between 2018 - 2020, was used for a retrospective cohort analysis of 247 patients with a histologically confirmed diagnosis of SMC identified using the ICD-O-3 code 8474. Demographic characteristics such as age, sex, race, Hispanic status, educational attainment, and Charleson-Deyo score were assessed using descriptive statistics. Incidence trends were interpreted via regression analysis. Results: 247 patients were identified in the database with a confirmed diagnosis of SMC, with a strong increasing incidence of patients diagnosed per year (R^2 = 0.860). Most individuals were non-Hispanic and White (83.0%). All patients were female (100.0%) with the mean age at diagnosis being 55.5 years old (SD = 15.4). The largest portion of patients fell into the lowest income quartile quartile of adults without a high school degree (27.5%). Over half of patients were diagnosed at stage I (54.3%) with the ovary as the primary site (98.0%). Most individuals had Charlson-Deyo co-morbidity scores of 0 (81.4%). Surgical resection of the primary site was performed in 99.2% of patients with negative margins being achieved in 60.7% of cases. The mean tumor size was 122.9 mm (SD = 80.7). The majority of patients did not receive palliative care (99.6%). The percent of patients that received chemotherapy, radiation, hormone therapy, and immunotherapy is 45.7%, 0.8%, 6.5%, and 1.6% respectively. The 30-day mortality rate was 0.8% with a 90-day mortality rate of 1.6%. The 2-year survival rate was 92.9% (SE = 0.02) with the mean survival at 42.9 months (SD = 0.91). Conclusions: This study represents the first NCDB analysis of SMC. Our results indicate that most cases of SMC were diagnosed at an early stage in majority non-Hispanic White female patients that were in their middle adulthood, with prior studies demonstrating a wider age range. Our results also exhibit SMC associated with a larger tumor size compared to other cancer types. These findings highlight the need for further investigation into SMC to better understand the impact of demographic and socioeconomic factors on the diagnosis, treatment, and overall survival of patients.