ASO Author Reflections: Recurrent Retroperitoneal Well-Differentiated Liposarcoma

Outcome after surgical resection of multiple recurrent retroperitoneal soft tissue sarcoma

INTRODUCTION

Local recurrences (LR) and distant metastases (DM) are common in retroperitoneal soft tissue sarcoma (RPS). Longer time to recurrence and resection of the recurrent lesion have been identified as beneficial prognostic factors for overall survival (OS) upon first tumor relapse. However, prognostic factors concerning OS upon subsequent recurrences are scarcely defined. In this study, we aimed to identify prognostic factors for post-relapse outcome in multiple recurrent RPS.

METHODS

Patients undergoing resection of primary and recurrent RPS at the University Hospital Heidelberg were retrospectively analyzed. Multivariable Cox regression analyses were performed to identify predictors of overall, LR- and DM-free survival. Subgroup analyses were performed for liposarcoma and leiomyosarcoma patients.

RESULTS

201 patients with primary disease, 101 patients with first, 66 patients with second and 43 patients with third LR as well as 75 patients with DM were analyzed. More than 12 months to recurrence and resection of recurrence were associated with improved OS after resection of first and second LR (5-year OS for first/second LR; resection: 64%/62%, no resection: 20%/46%). Gross macroscopic incomplete resection of first (p < 0.001), second (p = 0.001), and third recurrences (p < 0.001) was an independent prognostic factor for poor OS.

CONCLUSION

Development of LR and DM is frequent in RPS. Once a tumor relapsed, patients benefit from tumor resection not only in case of first, but also in case of subsequent recurrences.

Pathological prognostic factors of retroperitoneal liposarcoma: comprehensive clinicopathological analysis of 124 cases

Background

Retroperitoneal liposarcoma (RLS) is a type of rare malignant tumor. The aim of the present study was to study the correlations between the clinicopathological characteristics and the prognostic factors of RLSso as to delineate independent pathological indicators affecting prognosis.

Methods

The RLS pathological specimens were collected at Beijing Shijitan Hospital Affiliated to Capital Medical University from 2008 to 2018, and were used to study the histopathological features, including tumor size, histological types, lymphatic metastasis, tumor emboli in the blood and lymph vessels, and nerve invasion; immunohistochemical features, including Ki-67 and P53 proteins; and molecular pathological features, such as MDM2 (murine double minute2) gene amplification. Clinical treatment and follow-up data were collected, and the survival rate was calculated by Kaplan-Meier method. Univariate and multivariate survival analyses were performed to study the independent pathological factors.

Results

Of the 124 RLS cases, 63 were males (50.8%) and 61 were females (49.2%), with a median age of 52 years (range, 22-80 years). There were 51 cases (41.1%) of well-differentiated liposarcoma, 73 cases (57.3%) of dedifferentiated liposarcoma (DDL); 3 cases (2.4%) with lymph node metastases; 4 cases (3.2%) with tumor emboli in the vessels; 21 cases (16.9%) with Ki-67 label index <20% and 103 cases (83.1%) with Ki-67 label index ≥20%; and 81 cases (65.3%) with P53 <60% and 43 cases (24.7%) with P53 ≥60%. Fluorescence in situ hybridization studies revealed MDM2 gene amplification. Univariate analysis found the following pathological factors were correlated with prognosis: histopathological classification, recurrence, mitosis, tumor necrosis, Ki-67 label index, and P53. Multivariate analysis by Cox proportional hazard model found the following three independent pathological prognostic factors: age [hazard ratio (HR): 1.798, P=0.018], tumor site (HR: 1.263, P=0.002), tumor necrosis (HR: 1.984, P=0.024), and recurrence (HR: 2.161, P=0.049).

Conclusions

Age, tumor necrosis, tumor site, and recurrence could be independent pathological prognostic factors for RLS.