Prognostic Factors and Metastatic Patterns in Primary Myxoid/Round-Cell Liposarcoma

Abstract

Background. This study aimed to investigate prognostic factors for patients with myxoid/round-cell liposarcoma (MRCLS), in particular the significance of the round cell component, and to identify metastatic patterns as well as possibly suggest a suitable strategy for followup. Methods. Clinical, morphologic, and follow-up data from 160 patients with MRCLS was reviewed and statistically analysed. Results. Of 130 tumours with the round cell component evaluated, 61 had no round cell component, 27 had <5% round cell component, and 42 had >5%. All patients underwent surgical excision, 15 requiring amputation. 107 patients received adjuvant radiotherapy. Local recurrence occurred in 19 patients (12%), predominantly in patients with marginal or intralesional margins and a round cell component. Overall disease specific survival was 75% at 5 years and 56% at 10 years and was related to the proportion of round cell component. Of 52 patients who developed metastases, 38 (73%) had purely extrapulmonary metastases. We could not identify any factors predicting the site of metastases developing. Conclusions. The occurrence of any round cell component is the most important adverse prognostic factor for patients with MRCLS; patients with >5% round cell component are at higher risk of local recurrence, metastasis and tumour-related death and should be considered for adjuvant radiotherapy and possibly chemotherapy. The best method of monitoring extrapulmonary metastases remains to be established.

Localized and metastatic myxoid/round cell liposarcoma

“…Our 7.4% local recurrence rate is similar to that reported by a recently published large MLPS cohort 11 and is better than the rates reported in other published series, [8][9][10]12,13 perhaps because of more frequent positive margins reported by Haniball et al (34%), Kilpatrick et al (49%), and ten Heuvel et al (24%) compared with our current series (17%); less frequent use of radiotherapy; and/or the inclusion of patients with primary retroperitoneal myxoid lesions. Our preferred therapeutic approach since the 1980 s has been radiotherapy (50 grays) followed by surgery, which facilitates excellent local control with smaller radiation fields 17 than postoperative radiotherapy, which we reserve for patients who are referred to us after undergoing primary tumor resection elsewhere.…”

“…The results demonstrated excellent 1-year, 5-year, and 10-year DSS compared with previous studies. 2,[8][9][10] Univariate analysis suggested several variables as DSS prognostic factors (Table 4), supporting findings from previous studies. [8][9][10]12 However, multivariate Figure 1.…”

“…2,[8][9][10] Univariate analysis suggested several variables as DSS prognostic factors (Table 4), supporting findings from previous studies. [8][9][10]12 However, multivariate Figure 1. These Kaplan-Meier curves illustrate myxoid/round cell liposarcoma (MLPS)-specific survival stratified according to patients with (A) localized disease (n ¼ 207) versus metastatic disease (n ¼ 61; P < .0001; log-rank statistic), (B) primary disease (n ¼ 185) versus locally recurrent disease (n ¼ 22; P ¼ .0052; log-rank statistic), and (C) histologic myxoid variant (n ¼ 146) versus round cell variant (n ¼ 61; P ¼ .031; log-rank statistic).…”

“…Neither clinical factors (ie, age, resection margin status, tumor location) nor histologic factors (eg, necrosis) consistently correlate with outcome. 2,[8][9][10][11][12][13] Several studies have suggested that an RCL subtype either predicted prognosis 2,[8][9][10][11] or was not associated with prognosis, 12,13 differences perhaps caused by inconsistent assessment of round cell changes per se.…”

Hemoglobin, alkalic phosphatase, and C‐reactive protein predict the outcome in patients with liposarcoma

“…The subclassification of liposarcoma has a prognostic significance. 4 While highly differentiated liposarcoma only carry a risk of local recurrence, the pleopmorph and dedifferentiated liposarcoma are high rate malignancies with a high risk of metastatic disease. 4 As expected, patients with other histology than highly differentiated liposarcoma have a worse prognosis.…”