Extremity Myxoid Liposarcoma: Prognostic Factors and 20-Year Survival Outcomes

Research Article

Austin J Musculoskelet Disord. 2023; 10(1): 1062.

Extremity Myxoid Liposarcoma: Prognostic Factors and 20-Year Survival Outcomes

Machado P¹*, Peiró A¹, Trullols L¹, Sebio A1,2, Orellana R¹ and Gracia I1,2

¹Department of Orthopaedic Oncology, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain

²Institutd’Investigació Biomèdica Sant Pau (IIB SANT PAU), Barcelona, Spain

*Corresponding author: Pau MachadoDepartment of Orthopaedic Oncology, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain

Received: December 09, 2022; Accepted: January 17, 2023; Published: January 24, 2023


Introduction: Myxoid liposarcoma (MLS) is a rare, malignant musculoskeletal tumour. Due to the rarity of MLS, the factors associated with survival remain only partially understood. The aim of this retrospective study was to identify prognostic factors in patients with extremity MLS treated at our centre.

Methods: We reviewed the clinical records of 60 patients with extremity MLS treated at our hospital from 1997 to 2017. We evaluated patient- and tumour-related characteristics, as well as diagnostic and therapeutic procedures to determine their association with clinical outcomes, including local Recurrence-Free Survival (RFS), Metastasis-Free Survival (MFS) and Overall Survival (OS). Survival data were analyzed with the Kaplan-Meier method. Multivariate analyses were performed with Cox proportional-hazards regression.

Results: Overall survival at 5 years was 91%. On the multivariate analysis, surgical margins were an independent risk factor for MFS (Hazard Ratio [HR]: 10.98, 95% Confidence Interval [CI]:2.59-46.46), local RFS (HR: 9.34, 95% CI: 1.75-49.68), and OS (HR: 27.90, 95% CI: 5.01–155.50) (all p=0.001). Revision surgery was significantly associated (p=0.001) with higher local recurrence rates (HR: 99.13, 95% CI: 6.90–1423).

Conclusions: Surgical margins were an independent risk factor for MFS, local RFS, and OS. The need for revision surgery due to an unplanned excision was strongly associated with an increased risk of local recurrence, but not with MFS or OS. These findings underscore the importance of achieving clear surgical margins, especially in patients undergoing second-look surgery.

Keywords: Myxoid liposarcoma; Surgical Margins; Revision Surgery; Overall Survival; Local Recurrence-Free Survival.


Myxoid liposarcoma (MLS) is a rare, malignant musculoskeletal tumour composed of uniform, round to ovoid cells with variable numbers of lipoblasts, set in a myxoidstroma with a branching capillary vasculature. MLS accounts for approximately 20%-30% of all liposarcomas and 5% of all soft tissue sarcomas in adults, without significant sex predilection [1]. MLS typically presents as large, painless masses. Retroperitoneal MLS is usually due to a metastasis (M1) [2]. Multifocal disease, either synchronous or metachronous, indicates the presence of distant soft tissue metastases of monoclonal origin [3]. Diagnosis is supported by the detection of the characteristic chromosomal recurrent translocation, t (12;16) (q13;p11), which is present in > 95% of cases and indicates the aberrant fusion gene FUS-CHOP/DDIT3 [4]. Prognostic factors include age at diagnosis, tumour size and grade, depth, and surgical margins [5].

Currently, the mainstay of treatment for extremity MLS is wide excision surgery. Adjuvant radiotherapy plays an increasingly important role in the treatment of MLS, especially for the control of local recurrence. In fact, radiotherapy, with or without chemotherapy, has become common in the treatment of MLS [6]. Compared to other soft tissue sarcomas, MLS is re sponsive to chemotherapy, particularly anthracycline-based combinations and ifosfamide. In recent years, the combination of surgery, radiotherapy, and chemotherapy has been increasingly used to lower recurrence rates and increase both local control and overall survival (OS) [7]. Nevertheless, it is not clear which clinical and demographic variables have the greatest impact on survival outcomes.

In this context, we reviewed the clinical records of patients treated for extremity MLS at our institution in order to identify the variables that were independently associated with survival outcomes in this patient population.

Materials and Methods

This retrospective study included 60 patients treated for extremity MLS at our hospital (Hospital de la Santa Creu i Sant Pau; Barcelona, Spain) from 1997 to 2017. The study variables were evaluated to identify those that were independently associated with survival outcomes. We did not assess the influence of these variables by group or category. The following variables were included: patient characteristics (age and sex); tumour characteristics (size, location, stage, and histology); diagnostic and therapeutic procedures (type of surgery, margins, complications, neoadjuvant and adjuvant therapies). Survival outcomes were local Recurrence-Free Survival (RFS), Metastasis-Free Survival (MFS), and OS.

We included all patients with a pathological diagnosis of extremity MLS who underwent primary surgery at our centre. All of these patients underwent general examination before treatment, including magnetic resonance imaging (MRI) of the tumour. The diagnosis was based on clinical and imaging data, and confirmed preoperatively by biopsy and postoperatively by pathological examination of the resected tissue.

We also included patients referred from other centres for second-look surgery after an unplanned excision. Thus, the study included two patient profiles: patients who were diagnosed and underwent primary surgery at our hospital (n=45) and patients who underwent second-look surgery at our hospital (n=15). All of these patients had a marginal resection at some part of the tumour and all underwent MRI after the initial surgery, without evidence of macroscopic residual tumour at the surgical site.

Exclusion criteria were: (i) metastasis during initial treatment at our centre, (ii) incomplete clinical, radiographic, and/or pathologic records; (iii) lack of standardized follow-up data; (iv) death from other causes.

Follow-up time was calculated from the initial surgery until the final follow-up examination in the year 2019. All data were obtained from clinical records.

All cases (both primary and second-look patients) were reviewed by the multidisciplinary tumour board to select the most appropriate treatment. In all cases, the primary treatment decision was wide-margin surgery, which was performed in an attempt to completely eliminate the tumour tissue, according to International Union against Cancer (UICC) standards (R0 resection) [8]. In cases in which the tumour was located adjacent to critical structures (e.g., nerves, blood vessels, or bones), a planned marginal surgery was accepted (R1).

Most of the patients (57/60; 95%) underwent pre- or post-operative radiotherapy. However, in three cases (second-look surgery subgroup), radiotherapy was not considered necessary due to the expanded margins.

Chemotherapy was administered as appropriate in accordance with the tumour size, grade, and location. The chemotherapy type and schedule were based on the Spanish Sarcoma Research Group (GEIS) protocol in place at the time of treatment. This protocol consisted of three or five cycles of epirubicin (60mg/m2, days 1-2) or adriamycin (60-75mg/m2) plus ifosfamide (3g/m2, days 1-3) administered every 21 days.

During the postoperative follow-up, the patients were re-examined every 3 months for the first two years, every 6 months from years two to five, and annually thereafter. Local disease control, metastases and survival outcomes were recorded.

Statistical Analysis

All survival data were analysed using the Kaplan-Meier method. Multivariate statistics were performed using the Cox proportional-hazards regression model. Multiple comparisons of specific values between the groups were performed. Analysis of variance and chi-square tests were used for comparisons. Differences were considered statistically significant at p<0.05. The Stata statistical software package (v. 14) was used for data analysis.


General Results

A total of 60 patients (36 men, 24 women) with extremity MLS were included. The mean age was 47.1 years and the mean tumour diameter was 11.5 cm. Most tumours (n=58) were located in the lower extremities. Distribution according to cancer stage (AJCC TNM system) was as follows: stage 1 (36.7%), stage 2 (46.7%), and stage 3 (16.7%).

Wide resection (R0) was achieved in 49 patients and marginal resection (R1) in 11 patients. Most patients (95%) received radiotherapy and 38.3% received chemotherapy (Table 1).