Background: Dedifferentiated liposarcoma (DDL) is a high-grade tumor that either forms as a de novo tumor or as a progression from a low-grade, well-differentiated liposarcoma. DDL is a clinically aggressive tumor associated with low survival probabilities. Prognosis variables for DDL have never been reported in a large patient population.
Methods: 3,573 patients with primary DDL were analyzed from the National Cancer Database (NCDB). The 5- and 10-year survival probabilities were calculated, and the groups were compared using log-rank comparisons. Median survival was also calculated.
Results: Males comprised 65% of the cohort, 65.4% of the patients were between the age of 51-75 years old, and the median age at diagnosis was 64 years of age. Approximately 65% of tumors were > 10 cm, 89% had no metastases and the most common site of metastasis was the lung (2.5%). The most common tumors were found in the retroperitoneum or peritoneum (40.5%). Overall 5- and 10-year survival probabilities were 51.5% and 34.8%, respectively. Head and neck tumors had the best 5-year outcomes (86.4%) followed by extremities (67.1%), pelvis (65.8%), thorax or trunk (58.9%), retroperitoneum or peritoneum (45.3%), and abdomen (36.8%). Best outcomes were noted in the 26-50 year age group (5-year survival, 66.8%; 10-year survival, 52.9%), < 1 0 cm diameter size (5-year survival: 66.1%; 10-year survival, 46%), stage II (5-year survival, 66.7%), and moderately differentiated tumors (5-year survival, 68.3%). Radiation therapy yielded the best 5- and 10-year survival probabilities of 59% and 39.3%, respectively. Out of all the adjuvant therapies, surgery with radiation resulted in the best 5-year survival of 63.4%.
Conclusions: In the largest and most comprehensive study to date on DDL, major findings include that primary anatomical site is a significant prognostic variable and age at presentation, tumor size, stage, grade, and type of adjuvant therapy significantly affect median survival and overall survival probabilities.
