Single centre 30-year experience in treating retroperitoneal liposarcomas.

BACKGROUND AND OBJECTIVES Liposarcomas form a diverse group of tumors that represent the majority of retroperitoneal soft tissue sarcomas. Radical excision of these retroperitoneal liposarcomas is often challenging due to their large size and proximity to visceral organs and major vessels. Here we present the 30-year experience of our multidisciplinary sarcoma team in the treatment of these tumors and analysis of factors influencing survival. METHODS Patients with retroperitoneal liposarcomas treated in Helsinki University Hospital from 1987 to 2017 were reviewed. Local recurrence-free survival, metastases-free survival, and disease-specific survival were assessed with Kaplan-Meier analysis, and factors influencing survival were evaluated with Cox regression. RESULTS A total of 107 patients were identified. The median follow-up time was 5.4 years (interquartile range: 2.2-8.8 years). Local recurrence developed in 72% and metastases in 15% during follow-up. The 5-year disease-free survival was 31% and disease-specific survival was 66%. The multifactorial analysis revealed histological type and grade as predictors of disease-specific survival (P < .01) while multifocality carried a poor prognosis for local recurrence (P = .02) and higher histological grade for metastases (P < .01). CONCLUSIONS Retroperitoneal liposarcomas rarely metastasize but tend to recur locally. For tumors that have been resected with macroscopically clear margins, histological, type, and grade are significant predictors of survival.