Diagnosis, management, and outcome of patients with dedifferentiated liposarcoma systemic metastasis.

Background: Dedifferentiated liposarcomas (DDLPSs) result in worse patient outcomes than well-differentiated tumors despite shared molecular derangements. Prevalence and pattern of DDLPS systemic metastases have not been extensively reported; information regarding diagnosis, treatment, and outcomes of metastatic DDLPS patients is limited. Our study seeks to address this knowledge gap.

Methods: Metastatic patients were identified from a clinical database consisting of 277 DDLPS patients treated at the University of Texas M D Anderson Cancer Center (UTMDACC) (1993-2010). Only patients with radiologically demonstrable distant metastases were included. Patient, tumor, treatment, and outcome variables were recorded. Available imaging studies and tumor FFPE blocks were assessed.

Results: A total of 40 patients were identified, translating into a DDLPS metastatic rate of 14% (17% for de novo DDLPS and 9% for secondary dedifferentiation). The average patient age was 61 years with a male predilection. The retroperitoneum and lungs were the most common primary and metastatic tumor sites. Any of the 4 described DDLPS morphological subtypes harbored metastatic potential; MFH/UPS-like morphology was the most common. The median time from primary diagnosis to metastasis was 25 months; more than 50% of metastases developed without local failure. The median survival of metastatic patients was 11.5 months; the 5-year DSS was 5.2%. Patients amenable to complete surgical extirpation (n = 14) faired significantly better (P = .001; log rank).

Conclusions: Metastatic spread is an ominous consequence of DDLPS, especially regarding de novo tumors. Occurring relatively early in the course of disease and exhibiting a pulmonary predilection, these lesions are highly aggressive and commonly fatal. Further studies to identify metastatic biomarkers are needed.