Orbital Liposarcoma: A Surveillance, Epidemiology and End Results Database Study

Purpose: Orbital liposarcoma is a challenging tumor to treat due to its rarity and high rate of local recurrence, and the role of radiotherapy and chemotherapy remain unclear. Analysis of big data may improve our overall understanding of orbital disease and role of adjuvant therapies. Methods: Data were extracted from the Surveillance, Epidemiology and End Results (SEER) Research Plus database from 1975 to 2017. All patients with a diagnosis of liposarcoma (ICD-O3 codes 8850-8858, 8869-8862, 8870, 8880, 8881) were included. Cases were divided into 4 groups by primary site: orbit, retroperitoneum, soft tissue, and other. Results: A total of 16,958 patients were included. Patients with orbital involvement were younger and more likely to be female (p < 0.05). Among orbital lesions, myxoid liposarcoma was the most common histologic subtype (6/19; 31.6%) followed by well differentiated (5/19; 26.3%). This differed from the distribution of histologic subtypes encountered elsewhere, for which well-differentiated liposarcoma was the most common (retroperitoneum 979/3,136; 31%, soft tissue 3,493/11,671; 30%, and other sites 497/2,132; 23%, p < 0.05). Dedifferentiated histologic subtype was the second most common subtype found in the retroperitoneum (946/3,136; 30%), whereas it was less common in the orbit (2/19; 11%) and soft tissue (1,396/11,671; 12%) (p < 0.001). Patients with orbital liposarcoma had similar disease-specific mortality compared with soft-tissue location (p = 0.825) and lower disease-specific mortality compared with retroperitoneal location (p < 0.001). When all locations were combined, patients with well-differentiated liposarcoma had the lowest disease-specific mortality. Conclusions: Patients with orbital liposarcoma tend to be younger, female, and have a better prognosis than those with retroperitoneal disease, likely due to the lower incidence of dedifferentiated histologic subtype.