Recurrent Retroperitoneal Sarcoma Research Articles

Advancements in Diagnosis and Multimodal Treatment Strategies for Retroperitoneal Tumors: A Comprehensive Review.

Retroperitoneal tumors (RPTs) encompass both benign and malignant entities, constituting ~0.1% to 0.2% of all malignant tumors, of which 70% to 80% manifest malignancy. Predominantly, retroperitoneal sarcomas (RPS) represent the most prevalent subtype among RPT. With over 70 histologic forms identified, liposarcomas and leiomyosarcomas emerge as the primary constituents of RPS. Accurate diagnosis of RPTs necessitates preoperative core-needle biopsy and comprehensive imaging assessment. The current staging protocol for RPS relies on the eighth edition of the American Joint Committee on Cancer/TNM classification. Surgical excision remains the established gold standard for treating RPS. Therapeutic approaches vary according to the underlying pathophysiology. Although chemotherapy and radiotherapy exhibit efficacy in managing metastatic and recurrent unresectable RPS, their role in primary RPS remains unresolved, necessitating further clinical trials for validation. Concurrently, ongoing research explores the potential of targeted therapies and immunotherapy. This literature review aims to provide a comprehensive overview of existing research, delineating diagnostic pathways and optimal therapeutic strategies for RPT.

Preoperative Dose-Escalated Intensity-Modulated Radiotherapy (IMRT) and Intraoperative Radiation Therapy (IORT) in Patients with Retroperitoneal Soft-Tissue Sarcoma: Final Results of a Clinical Phase I/II Trial.

To report the final results of a prospective, one-armed, single-center phase I/II trial (NCT01566123). Between 2007 and 2017, 37 patients with primary or recurrent (N = 6) retroperitoneal sarcomas were enrolled. Treatment included preoperative IMRT of 45-50 Gy with a simultaneous integrated boost of 50-56 Gy, surgery and IORT. The primary endpoint was local control (LC) at 5 years. The most common histology was dedifferentiated liposarcoma (51%), followed by leiomyosarcoma (24%) and well-differentiated liposarcoma (14%). The majority of lesions were high-grade (FNCLCC G1: 30%, G2: 38%, G3: 27%, two missing). Five patients were excluded from LC analysis per protocol. The minimum follow-up of the survivors was 62 months (median: 109; maximum 162). IORT was performed for 27 patients. Thirty-five patients underwent gross total resection; the pathological resection margin was mostly R+ (80%) and, less often, R0 (20%). We observed 10 local recurrences. The 5-year LC of the whole cohort was 59.6%. Eleven patients received a dose > 50 Gy plus IORT boost; LC was 64.8%; the difference, however, was not significant (p = 0.588). Of 37 patients, 15 were alive and 22 deceased at the time of final analysis. The 5-year OS was 59.5% (68.8% per protocol). The primary endpoint of a 5-year LC of 70% was not met. This might be explained by the inclusion of recurrent disease and the high rate of G3 lesions and leiomyosarcoma, which have been shown to profit less from radiotherapy. Stratification by grading and histology should be considered for future studies.

Surgical treatment of recurrent retroperitoneal sarcoma in its different patterns: A 15-years’ two-centers experience

IntroductionThere is limited data available regarding the role of surgery in the treatment of retroperitoneal sarcoma (RPS) recurrences. We herein report the short- and mid-term outcomes of patients who underwent surgical treatment of RPS recurrences at two Italian centers over a 15-years’ experience. Materials and methodsFrom January 2005 to January 2020, 33 patients underwent surgical treatment of isolated locally recurrent RPS (LR group), locally recurrent RPS associated with the presence of distant recurrence (LR + DM group), and distant-only recurrent RPS (DM group). Only procedures performed to obtain a macroscopically radical treatment with curative intent were included. Data regarding pre-, intra-, post-operative course, and follow-up, collected in an Institutional database, were retrospectively analyzed, and compared. ResultsLR-group was composed of 15 patients, LR + DM group of 9 patients, and DM group of 9 patients. During the follow-up, 78.5% of the LR group, 77.8% of the DM group and 100% of the LR + DM group (p = 0.244) experienced a second recurrence. 7/11 (63.6%) patients in the LR group, 2/7 (28.5%) patients in the DM-group, and 0/9 (0.0%) patients in the LR + DM group underwent to almost one further local treatments of their recurrences (p = 0.010). No differences in the mean disease-free survival (p = 0.127), overall survival (OS) (p = 0.165) was reported among the three groups. Repeated surgery was an independent factor affecting survival in multivariate analysis (p = 0.01). ConclusionsA surgical treatment of RPS recurrences should always be taken into consideration, also in metastatic patients and/or in those who have already undergone surgery for previous RPS recurrence, because this approach may offer survival benefits.

Multidimensional characteristics, prognostic role, and preoperative prediction of peritoneal sarcomatosis in retroperitoneal sarcoma.

Peritoneal sarcomatosis (PS) could occur in patients with retroperitoneal sarcomas (RPS). This study aimed to expand the understanding of PS on its characteristics and prognostic role, and develop a nomogram to predict its occurrence preoperatively. Data of 211 consecutive patients with RPS who underwent surgical treatment between 2011 and 2019 was retrospectively reviewed. First, the clinicopathological characteristics of PS were summarized and analyzed. Second, the disease-specific survival (DSS) and recurrence-free survival (RFS) of patients were analyzed to evaluate the prognostic role of PS. Third, preoperative imaging, nearly the only way to detect PS preoperatively, was combined with other screened risk factors to develop a nomogram. The performance of the nomogram was assessed. Among the 211 patients, 49 (23.2%) patients had PS with an incidence of 13.0% in the primary patients and 35.4% in the recurrent patients. The highest incidence of PS occurred in dedifferentiated liposarcoma (25.3%) and undifferentiated pleomorphic sarcoma (25.0%). The diagnostic sensitivity of the preoperative imaging was 71.4% and its specificity was 92.6%. The maximum standardized uptake value (SUVmax) was elevated in patients with PS (P<0.001). IHC staining for liposarcoma revealed that the expression of VEGFR-2 was significantly higher in the PS group than that in the non-PS group (P = 0.008). Survival analysis (n =196) showed significantly worse DSS in the PS group than in non-PS group (median: 16.0 months vs. not reached, P < 0.001). In addition, PS was proven as one of the most significant prognostic predictors of both DSS and RFS by random survival forest algorithm. A nomogram to predict PS status was developed based on preoperative imaging combined with four risk factors including the presentation status (primary vs. recurrent), ascites, SUVmax, and tumor size. The nomogram significantly improved the diagnostic sensitivity compared to preoperative imaging alone (44/49, 89.8% vs. 35/49, 71.4%). The C-statistics of the nomogram was 0.932, and similar C-statistics (0.886) was achieved at internal cross-validation. PS is a significant prognostic indicator for RPS, and it occurs more often in recurrent RPS and in RPS with higher malignant tendency. The proposed nomogram is effective to predict PS preoperatively.

Patients with first recurrent retroperitoneal sarcoma that can be macroscopically completely resected can achieve comparable outcomes with that of primary patients after en bloc resection of tumor and adjacent organs.

The outcomes of patients with primary retroperitoneal sarcoma (RPS) are significantly superior to those with recurrence. En bloc resection of tumor and adjacent organs is recommended in primary RPS. However, whether en bloc resection of tumor and adjacent organs can benefit recurrent patients or some recurrent patients is unclear. We compared the outcomes of patients with primary RPS, first recurrence (RPS-Rec1), and ≥2 recurrences (≥RPS-Rec2) to evaluate the value and criteria for en bloc resection of tumor and adjacent organs in recurrent cases. We evaluated the safety of en bloc resection of tumor and adjacent organs by assessing operation time, blood loss volume, postoperative morbidities (POM), and efficacy by comparing local recurrence and peritoneal metastasis (LR-PM), distant metastasis, progression-free survival (PFS), and overall survival (OS). A total of 101, 47, and 30 patients with primary RPS, RPS-Rec1, and ≥RPS-Rec2 were included, respectively. Recurrent RPS invaded more adjacent organs and surrounding fat tissue than primary RPS. The operation time, amount of blood loss, incidence of grade III–V POM, LR-PM rate, PFS, and OS in the RPS-Rec1 group were similar to those of the primary group, both of which were significantly superior to those of the ≥RPS-Rec2 group. Macroscopically incomplete resection and high-grade RPS rather than first recurrence were independent risk factors for LR-PM, PFS, and OS. In conclusion, the safety and efficacy of en bloc resection of tumor and adjacent organs in RPS-Rec1 were comparable with those in primary RPS but significantly superior to those of ≥RPS-Rec2. For RPS-Rec1, comparable outcomes to patients with primary RPS can be achieved, particularly in those in whom a macroscopically complete resection is achieved.

Treatment algorithm and surgical outcome for primary and recurrent retroperitoneal sarcomas: A long‐term single‐center experience of 242 cases

Retroperitoneal sarcomas (RPSs) are difficult to manage, rare malignant tumors. This single-center, retrospective study aimed to analyze the treatment algorithm and outcomes of aggressive surgical treatment in patients with primary and recurrent RPS. Data of 242 consecutive patients with RPS who underwent surgical treatment at the Peking University Cancer Hospital Sarcoma Center between January 2010 and February 2021 were collected and analyzed. Indications for surgery were based on the treatment algorithm. A total of 145 patients with primary RPS and 97 with recurrent RPS were included. The recurrent cohort comprised more patients with multifocal tumors than the primary cohort (64.9% vs. 15.2%). R0/R1 resection was achieved in 94.5% and 81.4% of the primary and recurrent RPS cases, respectively. Major complication rates in the primary and recurrent cohorts were 17.9% and 30.9%, respectively. During a median follow-up of 51 months, the estimated 5-year overall survival, local recurrence, and distant metastasis rates for patients with primary and recurrent RPS were 61.0% versus 37.1%, 47.4% versus 71.3%, and 18.4% versus 17.6%, respectively. Aggressive surgical treatment achieved good local control and long-term survival in patients with primary RPS, whereas the prognosis in patients with recurrence were significantly worse.

Survival outcomes of surgery for retroperitoneal sarcomas: A systematic review and meta-analysis.

Definitive evidence to guide clinical practice on the principles of surgery for retroperitoneal sarcomas (RPSs) is still lacking. This study aims to summarise the available evidence to assess the relative benefits and disadvantages of an aggressive surgical approach with contiguous organ resection in patients with RPS, the association between surgical resection margins and survival outcomes, and the role of surgery in recurrent RPS. We searched PubMed, the Cochrane Library, and EMBASE for relevant randomised trials and observational studies published from inception up to May 1, 2021. Prospective or retrospective studies, published in the English language, providing outcome data with surgical treatment in patients with RPS were selected. The primary outcome was overall survival (OS). In total, 47 articles were analysed. There were no significant differences in the rates of OS (HR: 0.93; 95% CI: 0.83-1.03; P = 0.574) and recurrence-free survival (HR: 1.00; 95% CI: 0.74-1.27; P = 0.945) between the extended resection group and the tumour resection alone group. Organ resection did not increase postoperative mortality (OR: 1.00; 95% CI: 0.55-1.81; P = 0.997) but had a relatively higher complication rate (OR: 2.24, 95% CI: 0.94-5.34; P = 0.068). OS was higher in R0 than in R1 resection (HR: 1.34; 95% CI: 1.23-1.44; P < 0.001) and in R1 resection than in R2 resection (HR: 1.86; 95% CI: 1.35-2.36; P < 0.001). OS was also higher in R2 resection than in no surgery (HR: 1.26; 95% CI: 1.07-1.45; P < 0.001), however, subgroup analysis showed that the pooled HR in the trials reporting primary RPS was similar between the two groups (HR, 1.14; 95% CI, 0.87-1.42; P = 0.42). Surgical treatment achieves a significantly higher OS rate than does conservative treatment (HR: 2.42; 95% CI: 1.21-3.64; P < 0.001) for recurrent RPS. For primary RPS, curative-intent en bloc resection should be aimed, and adjacent organs with evidence of direct invasion must be resected to avoid R2 resection. For recurrent RPS, surgical resection should be considered as a priority. Incomplete resection remains to have a survival benefit in select patients with unresectable recurrent RPS.

Management of Locally Recurrent Retroperitoneal Sarcoma in the Adult: An Updated Consensus Approach from the Transatlantic Australasian Retroperitoneal Sarcoma Working Group.

Surgery is the mainstay of treatment for retroperitoneal sarcoma (RPS), but local recurrence is common. Biologic behavior and recurrence patterns differ significantly among histologic types of RPS, with implications for management. The Transatlantic Australasian RPS Working Group (TARPSWG) published a consensus approach to primary RPS, and to complement this, one for recurrent RPS in 2016. Since then, additional studies have been published, and collaborative discussion is ongoing to address the clinical challenges of local recurrence in RPS. An extensive literature search was performed, and the previous consensus statements for recurrent RPS were updated after review by TARPSWG members. The search included the most common RPS histologic types: liposarcoma, leiomyosarcoma, solitary fibrous tumor, undifferentiated pleomorphic sarcoma, and malignant peripheral nerve sheath tumor. Recurrent RPS management was evaluated from diagnosis to follow-up evaluation. For appropriately selected patients, resection is safe. Nomograms currently are available to help predict outcome after resection. These and other new findings have been combined with expert recommendations to provide 36 statements, each of which is attributed a level of evidence and grade of recommendation. In this updated document, more emphasis is placed on histologic type and clarification of the intent for surgical treatment, either curative or palliative. Overall, the fundamental tenet of optimal care for patients with recurrent RPS remains individualized treatment after multidisciplinary discussion by an experienced team with expertise in RPS. Updated consensus recommendations are provided to help guide decision-making for treatment of locally recurrent RPS and better selection of patients who would potentially benefit from surgery.

ASO Author Reflections: Management of Locally Recurrent Retroperitoneal Sarcoma: The Balance is Tipped Towards Biology.

ASO Author Reflections: Management of Locally Recurrent Retroperitoneal Sarcoma: The Balance is Tipped Towards Biology.

Analysis of the Effect of Tumor-Grade Change on the Prognosis of Retroperitoneal Sarcoma.

Simple SummaryChanges in tumor differentiation have been observed during local recurrence in retroperitoneal sarcoma (RPS), and these changes have been reported to affect prognosis. However, the change in the tumor grade from the primary tumor to the first local recurrence, and the effect of this change on long-term outcomes, are unknown. This study reports the presence of tumor-grade changes and their effect on patient prognosis. While the grade changes did not affect the patient’s prognosis, a high grade of the primary tumor was an important factor. In addition, the risk factor for second local recurrence was a high grade of the recurrent tumor. Although this finding cannot change the treatment plan for recurrent RPS, it can provide the details of nomograms to predict the patient prognosis.In retroperitoneal sarcoma (RPS), the change in the tumor grade from the primary tumor to the first local recurrence, and the effect of this change on prognosis, are unknown. The aim of this study is to analyze whether these changes affect the prognosis of RPS. Patients who underwent surgery for a first locally recurrent RPS at Samsung Medical Center from January 2001 to February 2020 were included. The pathologic features of primary and recurrent tumors were compared, and the outcomes were measured. A total of 49 patients were investigated. There were 25 patients with different grades of primary and recurrent tumors. The improving, stable, and worsening groups contained 16 (32.7%), 24 (49%), and 9 (18.3%) patients, respectively. There was no significant difference in the prognosis between the three groups. In the analyses of the factors that affect the OS, a high grade of the primary tumor (p = 0.023) and the size of the recurrent tumor (p = 0.032) were statistically significant in both univariate and multivariate analyses. In a factor analysis of the second LR, a high-grade recurrent tumor (p = 0.032) was the only significant factor. There were tumor-grade changes between the primary tumor and recurrent tumor in RPS. However, the most important factor in prognosis is a high grade of the primary tumor.

Management of recurrent retroperitoneal sarcomas

Recurrent retroperitoneal sarcomas are rare, with patterns of recurrence determined by the histologic subtype. A range of patient characteristics and treatment profiles combined with a myriad of presentations and clinical courses of recurrences make this diverse entity challenging to manage. Although surgical resection improves survival in select patients, the oncological outcomes are inferior to that of primary retroperitoneal sarcomas. Management options for unresectable disease include local ablative therapy, radiation and systemic therapy, with palliative surgery indicated occasionally. Attempts at disease control must be balanced with potential morbidity and impact on the patient's quality of life. This review aims to offer insights into the current understanding of recurrent retroperitoneal sarcomas and provide some guidance on management.

Prognostic Factors and Nomogram Construction for First Local Recurrent Retroperitoneal Sarcoma Following Surgical Resection: A Single Asian Cohort of 169 Cases.

ObjectiveThis study aimed to explore the prognostic factors for first local recurrent retroperitoneal soft tissue sarcoma (FLR-RPS) and construct predictive nomograms in the Asian population.MethodsIn a single Asian sarcoma center, data of patients with FLR-RPS were retrospectively analyzed from January 2011 to September 2020. We developed and internally validated prognostic factors determined by the Cox regression model, as well as nomograms for predicting recurrence-free survival (RFS) and overall survival (OS). The concordance index and calibration curve were used to determine the nomogram’s discriminative and predictive ability.ResultsWith 169 patients, the median follow-up duration was 48 months and the 5-year OS rate was 60.9% (95% confidence interval (CI), 51.9%–69.9%). OS was correlated with chemotherapy at the time of initial surgery and tumor grading. The 5-year cumulative local recurrence rate and distant metastasis rate were 75.9% (95% CI, 67.5%–84.3%) and 10.1% (95% CI, 4.2%–16.0%), respectively, and the length of the disease-free interval following the primary operation was associated with disease recurrence. The 6-year OS and cumulative recurrence rate after surgery in our cohort were comparable with those in the TARPSWG cohort, but the proportion of local recurrence was higher (80.4% vs. 59.0%), and distant metastasis was less common (10.1% vs. 14.6%). In this study, two nomogram prediction models were established, which could predict the 1-, 2-, and 5-year OS and RFS, and the concordance indices were 0.74 and 0.70, respectively. The calibration plots were excellent.ConclusionsFor the FLR-RPS patients, some can still achieve an ideal prognosis. The treatment of FLR-RPS in Asian populations can be aided by the predictive model established in this study.

Measuring the impact of complications after surgery for retroperitoneal sarcoma: Is comprehensive complication index better than Clavien-Dindo Classification?

BackgroundTo compare the Clavien-Dindo classification (CDC) and the Comprehensive Complication Index (CCI) in retroperitoneal sarcoma (RPS) surgery in assessing the real burden of post-operative complications on both post-operative length of stay and total costs of hospitalization (PLOS and TCH, respectively). Study designA series of 417 procedures for both primary and recurrent RPS between January 2000 and December 2017 was analyzed. Complications were classified according to both CDC and CCI. Univariable linear regressions were used to assess predictors associated with PLOS and TCH. Multivariable linear regression models were constructed to identify the factors independently associated with PLOS and TCH. ResultsMedian PLOS was 10 days (interquartile range [IQR] 7–16); median TCH was 7033.5€ (IQR 1350–305.900). Post-operative complications occurred in 170/417 (40.7%) of the procedures and in 75/417 (17.9%) of the procedures CDCs >3 were identified. Sixty-four (15.34%) patients had more than one complication. Univariable linear regression showed that both PLOS and TCH were significantly associated to both CDC and CCI among other factors. Multivariable linear analyses selected CDC and CCI as independent prognostic factors for both PLOS and TCH. According to the AIC and BIC, models including CCI performed better (5559.53 and 5598.18, respectively, compared with 5561.31 and 5599.95 for CDC models). ConclusionThe CCI resulted to perform better than the CDC in describing the overall burden of complications after RPS surgery, both for clinical and economic purposes.

Characteristics and Outcomes of Locally Recurrent Retroperitoneal Sarcoma After First Relapse in a Single Tertiary Asian Centre and Applicability of the Sarculator.

ObjectiveRetroperitoneal sarcomas (RPS) comprise of 15% of soft tissue sarcomas where five-year overall survival rate is about 50%. Locoregional recurrences are observed in up to 50% of patients within the first five years following resection. Various factors have been shown to influence survival outcomes, such as histological subtype and tumour size. A nomogram for first relapse locally recurrent RPS was developed using 602 patients from 22 centres. The recurrent RPS Sarculator is available in an electronic interface and includes variables of age, size, margins of re-resection, radiotherapy, chemotherapy and histology to predict for 6-year disease-free survival (DFS) and overall survival (OS). It has not been validated externally. This study aims to validate the Sarculator recurrence nomogram in predicting the survival outcomes of recurrent RPS in an Asian population as well as examine relapse patterns.MethodsPatients diagnosed with first recurrent RPS from 1 January 2000 to 31 December 2017 with first local relapse and eligible for curative re-resection were retrospectively analysed. The type of surgery was unique for individual patients and suggestions of adjuvant therapy were based on globally recognised standards. Patients were followed up every 3 to 4 months post-operatively for the first 2 to 3 years and 6-monthly to a year thereafter. A R0 or R1 margin is deemed as complete resection, including a microscopically negative margin (R0) and microscopically positive but macroscopically clear margin (R1). R2 is classified as an incomplete resection with tumour rupture or remaining disease. Harrell’s C concordance index was used to determine the nomogram’s discriminative ability and calibration plots were used to assess accuracy. For the calibration, the patients were divided into 3 groups. Death data was retrieved from the National Birth and Death registry for accuracy.ResultsThere were 53 patients included in this study. Patient and tumour characteristics have been summarised in Table 1. All patients had their second resection at a single centre. 66.0% had their first resection at the same centre. The median age was 53 (range 21- 79) at diagnosis, median tumour size was 17cm (12cm to 28cm) and median follow-up duration was 44.1 months. The most commonly encountered subtypes were de-differentiated liposarcoma (DDLPS) (56.6%), well-differentiated liposarcoma (WDLPS) (20.8%) and leiomyosarcoma (LMS) (11.3%) with a majority being high-grade (75.5%). The median disease-free interval was 2.9 years (2- 5.3 years) from the first surgery. The median age at second surgery was 56 (21- 79) and all patients had a complete resection (R0/R1). Recurrence patterns differed with subtypes where 90.9% and 9.1% of WDLS, 76.7% and 16.7% of DDLPS and 83.3% and 16.7% of LMS had local and distant relapses respectively from the second surgery. 62.5% of distant relapses was in the lung followed by nodes (18.8%) and liver (12.5%). The 5-year OS from the second surgery was 66.2% (95% CI: 54.3%- 80.8%). The 1-year, 3 years and 6 years DFS were 50.2% (95% CI: 38.2% - 65.9%), 10.4% (4.26% - 25.5%) and 3.91% (0.684% - 22.4%) respectively. Overall, 32 patients (60.4%) had passed away from sarcoma. The concordance indices for 6-year OS and DFS were 0.7 and 0.65 (Figure 1) respectively which represents a fairly accurate prediction by Sarculator.ConclusionOur study has shown the Sarculator nomogram for primary recurrent was applicable in our cohort and its potential application in an Asian setting. The Sarculator nomogram will be a useful tool in clinical practice to improve risk stratification and facilitate prognosis-based decision-making. Moving forward, novel therapeutic strategies are required to enhance the prognosis of patients with recurrent RPS.

Recurrent retroperitoneal sarcomas: Clinical outcomes of surgical treatment and prognostic factors

Recurrent retroperitoneal sarcomas: Clinical outcomes of surgical treatment and prognostic factors

Initial Clinical Experience With Novel Directional Low-Dose Rate Brachytherapy for Retroperitoneal Sarcoma

A novel Palladium-103 low-dose rate (LDR) brachytherapy device was developed to provide dose-escalation to the tumor bed after resection while shielding adjacent tissues. This multicenter report describes the initial experience with this device in patients with retroperitoneal sarcoma (RPS). Patients with recurrent RPS, prior radiotherapy, and/or concern for positive margins were considered. An LDR brachytherapy dose of 20-60 Gy was administered, corresponding to biologically effective dose values of 15-53 Gy and equivalent dose values of 12-43 Gy. Six patients underwent implantation at four institutions. Of these, five had recurrent disease in the retroperitoneum or pelvic sidewall, one had untreated locally advanced leiomyosarcoma, two had prior external beam radiation therapy at the time of initial diagnosis, and four received neoadjuvant external beam radiation therapy plus brachytherapy. The device was easily implanted and conformed to the treatment area. Median follow-up was 16 mo; radiation was delivered to the at-risk margin with minimal irradiation of adjacent structures. No local recurrences at the site of implantation, device migration, or radiation-related toxicities were observed. The novel LDR directional brachytherapy device successfully delivered a targeted dose escalation to treat RPS high-risk margins. Lack of radiation-related toxicity demonstrates its safety.

ASO Author Reflections: Selecting Patients for Recurrent Retroperitoneal Sarcoma Surgery: The Challenging Trade-Off Between Oncologic Outcome and Morbidity.

ASO Author Reflections: Selecting Patients for Recurrent Retroperitoneal Sarcoma Surgery: The Challenging Trade-Off Between Oncologic Outcome and Morbidity.

Aggressive and frequent resection of recurrences in retroperitoneal sarcoma contributes to long-term survival.

Retroperitoneal sarcoma (RPS) is a rare tumor with a poor prognosis and is often undetected until it is significantly enlarged. While surgical resection remains the primary treatment, there is little research on its benefits, especially that concerning the reoperation of recurrent disease. This study investigated the impact of surgical procedures, especially reoperation of recurrent RPS, on prognosis. This retrospective study included 51 patients who underwent radical resection surgery (R0 status) for primary or recurrent RPS without distant metastasis. Patient outcomes and prognosis were defined in terms of the clinicopathologic factors and surgical techniques performed. In all cases, the 5-year disease-free survival (DFS) rate was 28.2%, 5-year overall survival rate was 89.9%, and 5-year no residual liposarcoma rate was 54.3% after operation and re-reoperation. There was a statistically significant difference between the 5-year DFS rate and 5-year no residual liposarcoma rate due to frequent re-reoperation (p = 0.011). On univariate analysis of primary and recurrent lesions, the histological type and the number of organs involved were identified as statistically significant prognostic factors. Patients with well-differentiated liposarcomas had a statistically better prognosis than those with other cancer types (primary RPS, p = 0.028; recurrence, p = 0.024). Aggressive and frequent resection of recurrent RPS with combined resection of adjacent organs contributes to long-term survival. The establishment of a surgical strategy for RPS will require a prospective study.

Postoperative Morbidity After Resection of Recurrent Retroperitoneal Sarcoma: A Report from the Transatlantic Australasian RPS Working Group (TARPSWG).

This study aimed to evaluate perioperative morbidity after surgery for first locally recurrent (LR1) retroperitoneal sarcoma (RPS). Data concerning the safety of resecting recurrent RPS are lacking. Data were collected on all patients undergoing resection of RPS-LR1 at 22 Trans-Atlantic Australasian Retroperitoneal Sarcoma Working Group (TARPSWG) centers from 2002 to 2011. Uni- and multivariable logistic models were fitted to study the association between major (Clavien-Dindo grade ≥ 3) complications and patient/surgery characteristics as well as outcome. The resected organ score, a method of standardizing the number of organs resected, as previously described by the TARPSWG, was used. The 681 patients in this study had a median age of 59years, and 51.8% were female. The most common histologic subtype was de-differentiated liposarcoma (43%), the median resected organ score was 1, and 83.3% of the patients achieved an R0 or R1 resection. Major complications occurred for 16% of the patients, and the 90-day mortality rate was 0.4%. In the multivariable analysis, a transfusion requirement was found to be a significant predictor of major complications (p < 0.001) and worse overall survival (OS) (p = 0.010). However, having a major complication was not associated with a worse OS or a higher incidence of local recurrence or distant metastasis. A surgical approach to recurrent RPS is relatively safe and comparable with primary RPS in terms of complications and postoperative mortality when performed at specialized sarcoma centers. Because alternative effective therapies still are lacking, when indicated, resection of a recurrent RPS is a reasonable option. Every effort should be made to minimize the need for blood transfusions.

Retroperitoneal sarcomas: Outcomes of repeated resections.

Retroperitoneal sarcomas (RPS) are rare malignant tumors arising from mesenchymal cells. The objective of this study was to review the treatment experiences and to identify prognostic factors for overall survival (OS) after primary resection and subsequent reoperations for recurrences. The medical records of patients who underwent resection for RPS at our institution between June 2002 and December 2016 were retrospectively reviewed. Univariate and multivariable Cox proportional hazards modeling was used to assess the prognostic factors for OS. A total of 48 patients were enrolled. On multivariable analysis in primary resection group, the FNCLCC (Fédération Nationale des Centres de Lutte Contre le Cancer) grade was a significant prognostic factor for OS (P=0.006). The patients who received chemotherapy after primary resection were significantly associated with poor prognosis (P=0.009). The 5-year OS rate after primary resection (n=48) were 58.1% and the 5-year cumulative reoperation rate after primary resection was 62.5%. After second resection for recurrence after primary resection (n=23), the 5-year OS rate was 64.3%. There was a tendency towards decreased surgery-free survival rate as the number of repeated resections for recurrent RPS increased. In the subset of patients (n=16) who underwent more than 3 repeated resections at our institute, the 5-year OS rate was 75.0%, indicating that repeated resections are not associated with worse outcome. Only low tumor grade was an independent favorable prognostic factor for OS. Although the prognosis for RPS remains poor, repeated resections for recurrence are not associated with poor prognosis. Aggressive surgical strategies for recurred RPS patients are warranted.