Outcomes and Prognostic Factors for a Consecutive Case Series of 115 Patients with Somatic Leiomyosarcoma

Background: Leiomyosarcoma is an uncommon tumor that affects 500 to 1000 patients in the United States annually. The purpose of our study was to further define survival rates as well as to identify multivariable predictors of disease-specific mortality, local recurrence, and development of distant metastasis following surgical resection. Methods: We studied a consecutive series of patients treated for leiomyosarcoma at our institution (a tertiary-care referral center) over a ten-year period. Only patients with leiomyosarcoma of soft tissues, vasculature, or bone were included. Those with uterine, gastrointestinal, or cutaneous forms of the disease were excluded. This yielded a cohort of 115 patients with complete follow-up data on which statistical analysis was performed. Results: One-year, five-year, and ten-year disease-specific survival rates were 87%, 57%, and 19%, respectively. Tumor depth (p < 0.01), histological grade (p < 0.01), and metastasis at presentation (p = 0.03) were found to be multivariable predictors of mortality. Both retroperitoneal location (p = 0.01) and mitotic rate (p < 0.001) were predictive of distant metastasis. Resection margin was the only multivariable significant predictor of local recurrence in the group treated with surgical resection (p < 0.001). Conclusions: Leiomyosarcoma is an aggressive disease, with a generally poor prognosis. Depth of tumor and high histological grade are indicators of a poor prognosis. Retroperitoneal tumors have a particularly high potential to metastasize. Level of Evidence: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.