(P 330) LEIOMYOSARCOMA IN THE REAL WORLD: RETROSPECTIVE ANALYSIS OF CLINICAL CHARACTERISTICS AND TREATMENT PATTERNS IN PATIENTS AT A COMMUNITY ONCOLOGY CENTER IN SOUTH FLORIDA (MEMORIAL HEALTHCARE SYSTEM)

Objective: Leiomyosarcoma (LMS) is a rare, aggressive soft tissue sarcoma with heterogeneous presentations and limited data from community oncology settings. We conducted a retrospective analysis of patients treated for LMS at a large community oncology center in South Florida to characterize real-world demographics, tumor characteristics, treatment patterns, and survival outcomes.

Methods: We reviewed electronic medical records of patients diagnosed with LMS at Memorial Healthcare System (MHS) over the past decade. Only patients who received all modalities of treatment within the MHS system were included; those who received part of their care at outside institutions were excluded. Demographic data, tumor site, grade, stage at diagnosis, and treatment modalities were collected. Descriptive statistics were used to summarize the cohort. Kaplan-Meier methods were employed to estimate overall survival (OS).

Results: A total of 23 patients with histologically confirmed LMS were identified. The median age at diagnosis was 55 years (range: 34–78), with 60% female and 40% male. The racial distribution included 70% White, 20% Black, and 10% other races; 25% identified as Hispanic or Latino. The primary tumor site was uterine in 45% of cases, followed by extremities (30%), retroperitoneum (15%), and other locations (10%). Most tumors were high grade (80%), with the remainder being intermediate or low grade (20%). At diagnosis, 40% of patients presented with stage III disease, 35% with stage II, and 25% with stage IV.
Treatment modalities varied: 85% underwent surgical resection, 50% received radiation therapy, and 60% were treated with systemic therapy. Notably, 40% received all three modalities, indicating a multimodal approach in a significant portion of patients. Survival data, available for all patients, revealed a median OS of 24 months. The 1-year survival rate was 70%, decreasing to 40% at 3 years. The survival curve demonstrated a gradual decline, highlighting the aggressive nature of LMS.

Conclusion: This single-institution, real-world analysis provides insights into the clinical and demographic characteristics of LMS patients treated in a community oncology setting. A high proportion of patients presented with advanced-stage, high-grade tumors and underwent multimodal treatment. Despite comprehensive management, outcomes remain poor, emphasizing the need for continued research into effective treatment strategies and earlier detection in community-based populations.

Patient demographics, Tumor characteristics, Treatment patterns and Survival outcomes