Abstract 4370842: Incidence Trends of Primary Cardiac Sarcomas in the United States: A SEER-Based Analysis from 2000 to 2021

Introduction: Primary cardiac sarcomas are exceedingly rare and aggressive malignancies, with limited epidemiological data due to their low incidence. This study aims to characterize the incidence trends of cardiac sarcomas over a 21-year period using a population-based cancer registry and to assess differences in incidence by sex. Methods: We conducted a retrospective cohort study using data from the Surveillance, Epidemiology, and End Results (SEER) Program, accessed through SEER*Stat software version 8.4.5. Eligible cases were identified using the International Classification of Diseases for Oncology (ICD-O-3) site code C38.0 (Heart) and histology codes corresponding to soft tissue tumors and sarcomas, including: NOS (8800–8809), fibromatous neoplasms (8810–8839), myxomatous neoplasms (8840–8849), lipomatous neoplasms (8850–8889), myomatous neoplasms (8890–8929), complex mixed and stromal neoplasms (8930–8999), synovial-like neoplasms (9040–9049), and blood vessel tumors (9120–9169). The study period spanned from 2000 to 2021. Only first primary tumors were included, and no duplicate cases were identified. Incidence rates were age-adjusted to the 2000 U.S. standard population and stratified by sex. Temporal trends were evaluated using joinpoint regression. Results: A total of 264 cases of primary cardiac sarcomas were identified between 2000 and 2021. The overall age-adjusted incidence rate remained relatively stable throughout the study period, with no significant annual percent change observed. Males demonstrated a higher incidence rate compared to females (0.0065 vs. 0.0053 per 100,000 person-years, respectively), but this difference did not reach statistical significance (p > 0.05). There were no notable shifts in the incidence of specific sarcoma subtypes over time. Conclusion: This study provides one of the most comprehensive analyses of primary cardiac sarcoma incidence trends in the U.S. to date. Despite the rarity of this malignancy, the incidence has remained stable over the past two decades. While males appear to be more affected than females, the observed sex difference is not statistically significant. Continued surveillance and larger datasets are necessary to better understand risk factors and inform early detection strategies for this rare and often fatal disease.