Overall survival in abdominal wall sarcoma treated with curative intent surgery: A retrospective study from two European referral centres.

INTRODUCTION: Primary abdominal wall sarcomas are rare, heterogeneous tumours. The mainstay of management is surgery, although local recurrences (LR) and distant metastases (DM) are common. OBJECTIVES: Overall survival (OS) and disease-free survival (DFS) were primary outcomes; factors associated with prognosis secondary outcomes. MATERIALS AND METHODS: Patients undergoing surgery of primary abdominal wall sarcomas between April 2008 and May 2018 were identified at two referrals centres for sarcoma surgery. Patient demographics, tumour and treatment-related characteristics were recorded and analysed. RESULTS: A cohort of 65 patients underwent surgical resection with a median follow-up of 56 months, 5-year OS and DFS were 69% and 71%, respectively. Eleven patients (16.9%) experienced a recurrence event: 6 LR (9.2%), 10 DM (15.4%) and 5 both (7.7%). At univariate analysis, size (p = 0.03), grade (p = 0.001) and depth (p = 0.04) were associated with OS while size (p = 0.02) was associated with DFS. No significant relationship with tumour depth, type of surgery, surgical margin status or neo-/adjuvant treatment was demonstrated. CONCLUSION: Recurrence events are less common following treatment of abdominal wall sarcomas if compared to extremities STSs, but size (≥5 cm), high malignancy grade (FNCLCC 3) and depth are associated with worse OS.

Primary mesenteric sarcomas: Collaborative experience from the Trans-Atlantic Australasian Retroperitoneal Sarcoma Working Group (TARPSWG).

BACKGROUND: Primary mesenteric soft tissue sarcomas (STS) are rare and limited evidence is available to inform management. Surgical resection is challenging due to the proximity of vital structures and a need to preserve enteric function. OBJECTIVES: To determine the overall survival (OS) and recurrence-free survival (RFS) for patients undergoing primary resection for mesenteric STS. METHODS: The Trans-Atlantic Australasian Retroperitoneal Sarcoma Working Group (TARPSWG) is an intercontinental collaborative comprising specialist sarcoma centers. Data were collected retrospectively for all patients with mesenteric STS undergoing primary resection between 2000 and 2019. RESULTS: Fifty-six cases from 15 institutions were included. The spectrum of pathology was similar to the retroperitoneum, although of a higher grade. R0/R1 resection was achieved in 87%. Median OS was 56 months. OS was significantly shorter in higher-grade tumors (p = .018) and extensive resection (p < .001). No significant association between OS and resection margin or tumor size was detected. Rates of local recurrence (LR) and distant metastases (DM) at 5 years were 60% and 41%, respectively. Liver metastases were common (60%), reflecting portal drainage of the mesentery. CONCLUSION: Primary mesenteric sarcoma is rare, with a modest survival rate. LR and DM are frequent events. Liver metastases are common, highlighting the need for surveillance imaging.

Defining the role of neoadjuvant systemic therapy in high-risk retroperitoneal sarcoma: A multi-institutional study from the Transatlantic Australasian Retroperitoneal Sarcoma Working Group.

BACKGROUND: In patients with retroperitoneal sarcoma (RPS), the incidence of recurrence after surgery remains high. Novel treatment approaches are needed. This retrospective study evaluated patients with primary, high-risk RPS who received neoadjuvant systemic therapy followed by surgery to 1) determine the frequency and potential predictors of radiologic tumor responses and 2) assess clinical outcomes. METHODS: Clinicopathologic data were collected for eligible patients treated at 13 sarcoma referral centers from 2008 to 2018. Univariable and multivariable logistic models were performed to assess the association between clinical predictors and response. Overall survival (OS) and crude cumulative incidences of local recurrence and distant metastasis were compared. RESULTS: Data on 158 patients were analyzed. A median of 3 cycles of neoadjuvant systemic therapy (interquartile range, 2-4 cycles) were given. The regimens were mostly anthracycline based; however, there was significant heterogeneity. No patients demonstrated a complete response, 37 (23%) demonstrated a partial response (PR), 88 (56%) demonstrated stable disease, and 33 (21%) demonstrated progressive disease (PD) according to the Response Evaluation Criteria in Solid Tumors, version 1.1. Only a higher number of cycles given was positively associated with PR (P = .005). All patients underwent complete resection, regardless of the tumor response. Overall, patients whose tumors demonstrated PD before surgery showed markedly worse OS (P = .005). An indication of a better clinical outcome was seen in specific regimens given for grade 3 dedifferentiated liposarcoma and leiomyosarcoma. CONCLUSIONS: In patients with high-risk RPS, the response to neoadjuvant systemic therapy is fair overall. Disease progression on therapy may be used to predict survival after surgery. Subtype-specific regimens should be further validated.

Staging, nomograms and other predictive tools in retroperitoneal soft tissue sarcoma.

Patient outcomes following surgical resection of retroperitoneal sarcomas (RPSs) are variable and therefore predicting prognosis is challenging. The risk of recurrence varies according to several patient- tumour- and treatment-related characteristics, including histological subtype and tumour grade. In an era of increased movement towards individualised patient care, the ability to predict prognosis following surgery for RPS is essential. The accurate prediction of an individual patient's outcome is important to allow adequate patient counselling and to ensure the optimal therapeutic strategy is selected. The outcomes of patients who have undergone resection for RPS can be predicted using tools such as nomograms. Nomograms take into account the relative contribution of each variable by giving them different weights and then combining them. This review aims to discuss current staging systems available for RPS and to critically appraise predictive tools that are currently available for use in clinical practice.