Efficacy of neoadjuvant hypofractionated radiotherapy in patients with locally advanced myxoid liposarcoma

Myxoid liposarcoma (MLPS) has been reported to be more radiosensitive compared with other soft tissue sarcomas (STS). The use of preoperative hypofractionated radiotherapy 5 × 5 Gy for five consecutive days, and then immediate surgery in patients with locally advanced STS showed a good local control rate. The main objective of our work was to assess the efficacy of hypofractionated radiotherapy in preoperative setting in patients with locally advanced primary MLPS.

From February 1999 to March 2014, 32 patients with primary MLPS were treated with preoperative hypofractionated radiotherapy for 5 consecutive days followed by immediate surgery (median dose 5 × 5 Gy). Median size of the tumor 10.5 cm. In one patient the tumor was located on the upper extremity, the other (31 patients) had their tumors located on the lower extremity.

In 90% patients histologically negative surgical margins (R0) were obtained. 34% patients had distant recurrence of the disease, local recurrence was found in 9.3% of the patients. 5-year local relapse-free survival rate was 90% and overall survival was 68%. In all analyzed surgical specimens the radiotherapy response features (hyalinization, fibrosis, paucicelularity, hemorrhages, dilatation of vessels) were detected. We have not found statistically significant differences in terms of OS and LRFS for RCC component, tumor grade, BCL2, TP53, postsurgery necrosis and tumor size. In postradiotherapy specimens significantly higher positivity of TP53 expression was detected as compared to primary biopsies.

Combined therapy with hypofractionated radiotherapy followed by immediate surgery seems to be effective therapy in MLPS demonstrating good local control and pathological response to therapy.