Primary anatomical site, adjuvant therapy, and other prognostic variables for dedifferentiated liposarcoma.

BACKGROUND: Dedifferentiated liposarcoma (DDLPS) is a high-grade, clinically aggressive tumor associated with low survival probabilities. Prognostic variables for DDLPS have not been previously reported in a large patient population.

METHODS: A total of 3573 patients with primary DDLPS were analyzed from the National Cancer Data Base (NCDB). The 5- and 10-year survival probabilities were calculated, and the groups were compared using log-rank comparisons and multivariable Cox hazard regression analysis. Median survival was also calculated.

RESULTS: Males comprised 65% of the cohort, the median age at diagnosis was 64 years of age, and 65.4% of the patients were between 51 and 75 years of age. The most common site for primary tumors is the retroperitoneum or abdomen (59.5%). Head or neck tumors had the best 5-year outcomes (86.4%) followed by extremities (67.1%), pelvis (65.8%), thorax or trunk (58.9%), and finally retroperitoneum or abdomen (42.6%). Best outcomes were noted in the 26- to 50-year-old age group (5-year survival:66.8%), < 10 cm size (5-year survival:66.1%), FNCLCC grade 1 (5-year survival:69.2%), and stage II disease (5-year survival:66.7%). Radiation therapy yielded the best 5-year and 10-year survival probabilities of 59% and 39.3%, respectively. Out of all the adjuvant therapies, the use of radiation resulted in the best 5-year survival of 63.4%.

CONCLUSION: In the largest and most comprehensive study to date on DDLPS, major findings include primary site as a significant prognostic variable with age at presentation, sex, tumor stage, and type of adjuvant therapy significantly impacting overall survival.