Metastatic Pattern of Truncal and Extremity Leiomyosarcoma: Retrospective Analysis of Predictors, Outcomes, and Detection

Abstract BackgroundLeiomyosarcomas (LMS) are a heterogenous group of malignant mesenchymal neoplasms with smooth muscle origin and are classified as either non-uterine (NULMS) or uterine (ULMS). Metastatic pattern, prognostic factors, and ideal staging/surveillance studies for truncal and extremity LMS have not been defined.MethodsA retrospective analysis of patients diagnosed with histopathology-confirmed truncal or extremity LMS between 2009-2019 was conducted. Data collected included demographics, tumor characteristics, staging, surveillance, and survival endpoints. Primary site was defined as either 1. Extremity, 2. Flank/Pelvis, or 3. Chest wall/Spine.ResultsWe identified 73 patients, 23.3% of which had metastatic LMS at primary diagnosis, while 68.5% developed metastatic disease at any point. The mean metastatic-free survival from primary diagnosis of localized LMS was 3.0±2.8 years. Analysis of prognostic factors revealed that greater age (≥50 years) at initial diagnosis (OR=3.74, p=0.0003) and higher tumor grades II (OR=16, p=0.019) and III (OR=13, p=0.025) were significantly associated with metastases.ConclusionsTruncal and peripheral extremity LMS is an aggressive tumor with high metastatic potential. While there is a significant risk of metastases to lungs, extra-pulmonary tumors are relatively frequent. Older patients and patients with higher-grade (II/III) tumors carry an increased risk of developing metastatic disease.