Abstract
e23538 Background: Mixed type rhabdomyosarcoma is a rare soft tissue tumor characterized by the presence of two histologically different subtypes of rhabdomyosarcoma, commonly found in the testis. Despite a majority of the patients undergoing aggressive treatment, the prognosis is poor. Analysis of its diagnostic trends could prove valuable in understanding mixed type rhabdomyosarcoma’s epidemiology. The 2004-2020 National Cancer Database (NCDB) was analyzed to determine the demographic factors of patients with mixed type rhabdomyosarcoma. Methods: A retrospective cohort analysis of the 2004–2020 NCDB, using ICD-O-3 code 8902/3, included patients diagnosed with mixed type rhabdomyosarcoma (N = 94). Descriptive statistics were used to analyze various demographic factors such as sex, age, race, Hispanic status, educational background, insurance status, facility type and location, distance from facility, and Charlson-Deyo score. Incidence trends were examined through regression analysis. Results: The NCDB identified a total of 94 patients with a confirmed diagnosis of mixed type rhabdomyosarcoma from 2004-2020, with a slight decline in incidences diagnosed per year (R² = 0.0903). Females had a slightly higher likelihood of being diagnosed (55%) compared to males (45%), with average age at diagnosis being 40.06 years (SD = 2.8, Range = 1-90). The majority of patients were White (72%) and of non-Hispanic descent (82%). The top primary site was the testis (23%), with endometrium being another major site (15%). Most (83%) patients had a Charles/Deyo comorbidity score of 0. All patients received immunotherapy as primary treatment. Most (46%) patients were privately insured. A majority (26%) of patients received treatment at an academic/research program. A greater number (53%) of patients resided in metropolitan counties with a population larger than 1 million. Most (40%) patients belonged to the highest quartile of income earners of $74,063 or greater. Conclusions: Our research on mixed type rhabdomyosarcoma, the first NCDB analysis of its kind, aims to address a notable knowledge gap on the topic. Similar to information presented in earlier studies, our analysis revealed mixed type rhabdomyosarcoma has a relatively poor prognosis and is mostly observed in White, Non-Hispanic individuals. Analysis on the demographics of this patient population revealed most patients were top quartile income earners, resided in a metropolitan location, and were more likely to be treated at an academic/research program. Further research should aim to better understand the impact of such demographic and socioeconomic features on the diagnosis, treatment plans, and overall mortality rates of patients with mixed type rhabdomyosarcoma.