Abstract Body (Do not enter title and authors here): Background: Heart tumors pose significant diagnostic and therapeutic challenges. Understanding their prevalence and prognostic factors is crucial for improving patient outcomes.

Hypothesis: Tumor stage, histologic subtype, age, and chemotherapy use independently predict survival in patients with primary heart tumors.

Aim: To evaluate the prognostic impact of tumor stage, histologic subtype, age, and treatment modalities on cancer-specific survival in patients with primary heart tumors.

Methods: We analyzed the US Surveillance, Epidemiology, and End Results database from 2000 to 2020. 1,086 patients diagnosed with heart tumors were included in our analysis. Descriptive statistics, including means and standard deviations for age, and proportions for categorical variables such as gender, surgery, radiotherapy, chemotherapy, tumor category, and stage, were calculated. Risk factors with a p<0.1 were included in a multivariate Cox regression model to identify significant prognostic factors for cancer-specific survival.

Results: The mean age of the patients was 52.1 years (SD = 20.36). The gender distribution was 47.67% female and 52.33% male. Among the patients, 46.09% did not undergo surgery, and 16.21% received radiotherapy. Chemotherapy was administered to 57.54% of the patients. The tumors were categorized as sarcomas (46.51%), lymphomas (23.84%), carcinomas (0.93%), other tumors (1.51%). The stages of tumors were classified as localized (35.64%), regional (27.54%), and distant (36.82%). The median survival was 21 months. Patients with regional stage tumors had a significantly worse survival compared to those with localized tumors (adjusted hazard ratio [aHR] = 1.632, p = 0.0024). Distant stage tumors had a significantly worse survival compared to those with localized tumors (aHR = 2.114, p < 0.0001). Chemotherapy was associated with better survival (aHR = 0.7174, p = 0.0101). Increasing age was associated with worse survival (aHR = 1.016, 95%, p < 0.0001). Compared to sarcomas, survival was not significantly different for carcinomas (aHR = 1.083, p = 0.8789), while lymphomas (aHR = 0.2970, p < 0.0001) and other tumor types (aHR = 0.2034, p = 0.0257) had better survival.

Conclusion: This study highlights the prevalence of various heart tumor types and identifies critical prognostic factors. Advanced stage at diagnosis, increasing age, and specific tumor categories significantly influence survival outcomes. Chemotherapy was found to be beneficial for survival.