(P 320) CLINICAL CHARACTERISTICS AND RECURRENCE PATTERNS IN HISPANIC VS. NON-HISPANIC PATIENTS WITH LEIOMYOSARCOMA: FINDINGS FROM A RETROSPECTIVE SINGLE-CENTER COHORT STUDY

Objective: Leiomyosarcoma (LMS), a rare and aggressive malignancy, commonly arises from the uterus, retroperitoneum, and extremities, carrying a poor prognosis. This study investigates differences in clinical characteristics, treatment patterns, outcomes, and genomic data from next-generation sequencing (NGS) between Hispanic and non-Hispanic patients with non-metastatic and metastatic LMS. The goal is to identify disparities that may inform personalized treatment strategies and improve outcomes for underrepresented populations.

Methods: This single-center retrospective cohort study, conducted under an IRB-approved protocol, evaluated 190 patients with biopsy-proven LMS, confirmed by sarcoma pathologists at the University of Miami Sylvester Cancer Center. NGS data were collected for patients tested between January 2009 and December 2024. Patient demographics, including sex, ethnicity, and age, along with clinical variables such as tumor location, size, grade, and recurrence, were gathered from electronic medical records and stored in REDCap. Kaplan-Meier and logistic regression models were used for survival analysis, adjusting for confounding variables. Patients with incomplete clinical histories were excluded.

Results: The dataset included 190 patients (154 females, 33 males) with a median age of 55.8 years. Of these, 55 were metastatic, and 132 were nonmetastatic. Among nonmetastatic patients, 81 were high grade, including 55 non-Hispanic and 26 Hispanic patients.
In the nonmetastatic, high-grade LMS cohort, disparities were observed: 5-year overall survival (OS) was 87.7% for non-Hispanics compared to 76.2% for Hispanics (p=0.045; hazard ratio: 1.96). Median disease-free survival (DFS) was shorter for Hispanics (14.3 months) than for non-Hispanics (50.7 months), indicating earlier recurrence among Hispanics (p=0.32). At 24 months, DFS was 39.4% for Hispanics versus 72.2% for non-Hispanics. Initial therapies, including radiation, surgery, and systemic treatments, showed no significant differences in recurrence rates, though non-Hispanic patients were more likely to receive radiation.

Conclusion: These findings highlight survival disparities between Hispanics and non-Hispanics, potentially driven by earlier recurrence. NGS data from 38 patients' diagnostic tissue will be analyzed to identify potential drivers of these disparities and inform equitable treatment strategies.

Clinical Characteristics in Patients with High Grade, Nonmetastatic Leiomyosarcoma