Marginal excision of dedifferentiated liposarcoma of the limbs without radiation may be safe in select patients.

AIMS: Dedifferentiated liposarcoma (DDLPS) is a heterogeneous tumour consisting of low-grade atypical lipomatous tumour (ALT) and high-grade sarcomatous components. This study evaluates local recurrence and metastasis rates after resection of a limb DDLPS, focusing on the impact of tumour grade at surgical margins and the role of adjuvant radiation therapy.

METHODS: A retrospective analysis was conducted of 137 patients with a pathologically confirmed limb DDLPS who underwent surgical resection between July 1995 and September 2024. Outcomes assessed included local recurrence-free survival, metastasis-free survival, and overall survival. Statistical analyses used chi-squared tests for categorical variables, independent-samples t-tests for continuous variables, and Kaplan-Meier survival estimates.

RESULTS: Of the 137 patients (mean age 67 years (28 to 96); mean tumour size 16 cm (2.4 to 39)), 54.7% (n = 75) had negative surgical margins, and 45.3% (n = 62) had positive margins. Of those with positive margins, 48.3% involved only the ALT component. Notably, patients with positive margins confined to the ALT component who did not receive radiation therapy 40% (n = 12) exhibited no local recurrences or metastases. Those patients with negative margins who were treated without radiation therapy (n = 21; 28%) had low rates of recurrence (n = 1; 4.7%) and metastasis (n = 5; 23%).

CONCLUSION: Patients with DDLPS can expect high rates of local control and overall survival. In select cases of limb DDLPS in which positive surgical margins are limited to the ALT component, marginal excision without adjuvant radiation therapy may be oncologically safe, offering comparable oncological outcomes to those with negative margins. This approach can enhance functional preservation by avoiding unnecessary exposure to radiation.