Predictors of improved survival for patients with retroperitoneal sarcoma

Efficacy of surgery in the management of multiple recurrences of retroperitoneal dedifferentiated liposarcoma

BACKGROUND

Retroperitoneal dedifferentiated liposarcoma is associated with a high risk of recurrence; however, treatment strategies that are more effective than surgery remain to be established. This study aimed to determine the optimal number of surgeries that would be effective for patients with recurrent disease. Furthermore, the improvement in prognosis was evaluated according to the malignancy level.

METHODS

The effect of each type of surgery on the prognosis of 118 patients with retroperitoneal dedifferentiated liposarcoma treated at the Osaka International Cancer Institute between 1997 and 2022 was investigated. Among the 118 patients, 103 underwent initial surgery, while 54 and 30 patients underwent second and third surgeries, respectively. The overall and disease-free survival rates of each group were compared using the Kaplan-Meier method, and the log-rank test was used to determine statistical significance in univariate analysis. 18F-Fluorodeoxyglucose Positron Emission Tomography (FDG-PET) was used to assess malignancy. Maximum standardized uptake values (SUVmax) of ≥ 4 and < 4 were classified as high and low malignancy, respectively.

RESULTS

The first and second surgeries resulted in a significant improvement in the overall survival rate, regardless of the malignancy level (p < 0.001); however, no significant improvement in prognosis was observed after the third surgery (p = 0.077). Low-grade malignancies are associated with a better postoperative prognosis, even in cases of recurrence. In contrast, high-grade malignancies exhibit a reduction in surgical efficacy.

CONCLUSIONS

This study highlights the importance of considering the tumor malignancy level and the patient's overall condition when deciding whether to perform repeated surgical interventions. Surgical treatment can prolong overall survival, even in patients with recurrence; however, it is advisable to assess malignancy levels when determining the suitability of surgery beyond the second recurrence.

Survival and prognostic factors of primary retroperitoneal sarcomas after surgery: a single-center experience

PURPOSE

The percentage of retroperitoneal sarcomas (RPS) among all soft tissue sarcomas ranges from 10 to 15%. Surgery remains the gold standard for RPS. In this study, we analyzed the impact of surgical treatment for primary RPS on recurrence and overall mortality at a Chinese institution and identified and evaluated prognostic variables.

METHODS

Data from patients with RPS who underwent surgical treatment were retrospectively analyzed. The patients were treated at a single center from January 2000 to June 2018. Retrospectively collected demographic, clinicopathological, and surgical factors were examined. Overall survival (OS) and disease-free survival (DSF) were used as the primary endpoints. Predicted 5-year survival rates, encompassing both DFS and OS, were derived from the Sarculator prognostic nomogram.

RESULTS

A total of 110 patients met the inclusion criteria. The median follow-up time after surgery for patients with primary RPS was 5.3 years. During this period, 59 patients died. The 5-year OS and DFS estimates were 63.5% and 35.3%, respectively. In a multivariate analysis, poor OS following surgical treatment of primary RPS was independently correlated with FNCLCC grade (p < 0.001) and surgical margin status (p = 0.016). FNCLCC grade (p = 0.001) and surgical margin status (p = 0.002) were also independently associated with poor DFS. The C-indices for 5-year OS and DFS survival utilizing the Sarculator prognostic nomogram were 0.71 and 0.73 respectively.

CONCLUSION

The overall mortality rate of patients with RPS was considered acceptable. OS and DFS prognostic markers were established for primary RPS. Tumor grade and intraregional margins are other factors that affect survival and recurrence.

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.

Retroperitoneal sarcoma: a 10-year follow-up analysis using hospital-based cancer registry data in Japan

OBJECTIVES

We sought clinical characteristics, survival outcomes, and prognostic factors for overall survival of retroperitoneal sarcoma in Japan.

METHODS

A Japanese hospital-based cancer registry database with a pivotal 10-year follow-up was used to identify and enroll patients, registered from 106 institutions, diagnosed with retroperitoneal sarcoma in 2008-2009. Treating hospitals were divided by hospital care volume; high-volume hospitals and low-volume hospitals were defined as ≥ 4 and < 4 cases/year, respectively.

RESULTS

A total of 91 men and 97 women were included, with a median age of 64 years. The most common histological type was liposarcoma in 101 patients, followed by leiomyosarcoma in 38 patients. The 5-year and 10-year overall survival rates were 44.1 and 28.3%. The majority of patients (n = 152, 80.9%) were treated at low-volume hospitals. High-volume hospital patients had higher 10-year overall survival rates than low-volume hospital patients (51.2% vs 23.2%, P = 0.026). Multivariate analysis revealed age over 60 years, treatment in low-volume hospitals and chemotherapy were independent predictors of unfavorable survival while treatment with surgery was an independent predictor of favorable survival.

CONCLUSIONS

The possibility of surgical removal was suggested to be the most important prognostic factor for retroperitoneal sarcoma. Better survival was shown in patients treated at high-volume hospitals in our series.

Survival Outcome of Retroperitoneal Sarcomas Treated With a Surgery-First Approach: A Single-Center Experience

Background Retroperitoneal sarcomas (RPS) are rare and complex tumors originating from the retroperitoneal space, an anatomical region nestled behind the abdominal cavity and shielded by the posterior abdominal wall. Late clinical presentation is a hallmark of retroperitoneal sarcomas. The symptoms are often nonspecific, and nodal metastases are rare. Computed tomography (CT) remains the investigation of choice, and a preoperative biopsy is usually not needed. Surgical resection remains the mainstay of treatment, along with adjuvant radiation and chemotherapy. Survival rates are in general poor, even after complete resection. In this study, we attempt to shed some light on the clinicopathological profiling of retroperitoneal sarcomas and their survival outcomes. Objective The objective of this study is to assess the demographic, clinical, and pathological profiling of patients with retroperitoneal sarcoma and to study the survival of patients with retroperitoneal sarcoma. Methodology We conducted a hospital-based retrospective observational study in a tertiary care center in South India between January 2011 and January 2021. We included all patients with histopathologically proven retroperitoneal sarcoma. Metastatic cases and those who underwent chemotherapy or radiation prior to presentation were excluded. Their demographics, pathological reports, and survival were followed up and collected, and statistical analysis was done. Results The study included 16 cases with retroperitoneal sarcomas across the decade in which the data was collected, confirming the rarity of the tumor, out of which more than 40% of patients were above the age of 60. The most common symptom was found to be a bloating sensation in nine patients, followed by abdominal pain in three patients. Seventy-five percent of the patients were found to have a T4 (i.e., a size of more than 15 cm) tumor at presentation. Well-differentiated liposarcoma was found to be the most common pathological variant accounting for 25% of the cases. The mean survival was found to be 8.05 years, which dropped to 5.74 years in Grade 3 tumors. Conclusion Retroperitoneal sarcomas are rare tumors of which liposarcoma is the most common variant. A significant reduction in the mean survival was identified in Grade 3 sarcomas compared to the cumulative survival time of Grade 1 and Grade 2 retroperitoneal sarcomas.

The role of radiation therapy in the management of primary retroperitoneal sarcoma: A systematic review and clinical practice guidelines from the Australia and New Zealand Sarcoma Association

While surgery is the mainstay of treatment for localised retroperitoneal sarcoma, the use of radiotherapy (RT) remains controversial. This systematic review aimed to evaluate the role of RT for retroperitoneal sarcoma. A systematic review using the population, intervention, comparison, and outcome model from 1990 to 2022 identified 66 studies (a mixture of preoperative and postoperative RT); one randomised controlled trial (RCT) with two publications, 18 registry studies, and 46 retrospective studies. In the RCT of preoperative RT, there was no difference in local/abdominal recurrence. The pooled analysis of this RCT and a retrospective study showed a significant abdominal recurrence free survival benefit with preoperative RT in low grade liposarcoma. The RCT and the majority of retrospective series found RT did not improve recurrence free survival (11 of 16 no difference in combined local and distant RFS, 11 of 13 no difference in distant metastasis free survival), disease specific survival (9 of 12 studies) or overall survival (33 of 49 studies). The majority of studies found no association between RT and perioperative morbidity. In summary, preoperative RT may improve local control for low grade (well-differentiated or grades 1-2 dedifferentiated) liposarcoma, but not other histological subtypes. There is no strong evidence that perioperative RT provides an overall survival benefit. Patients with low grade retroperitoneal liposarcoma can be considered for preoperative RT to improve abdominal recurrence free survival. The rationale and level of evidence in this scenario should be carefully discussed by the multidisciplinary team with patients. RT should not be routinely recommended for other histological subtypes.

Epidemiology, pathological characteristics and survival of retroperitoneal soft‑tissue sarcomas compared with non‑retroperitoneal soft tissue sarcomas

Retroperitoneal soft-tissue sarcomas (RPS) are rare forms of mesenchymal tumors that account for ~0.15% of all malignancies. The purpose of the present study was to determine the differences between RPS and non-RPS anatomopathological and clinical features and to analyze whether the hazard ratio for short-term mortality differs between patients with RPS and non-RPS, after adjusting for differences in baseline anatomopathological and clinical features. The Veneto Cancer Registry, a high-resolution population-based dataset spanning the regional population, was used as a data source for the analysis. The current analysis focuses on all incident cases of soft-tissue sarcoma recorded by the Registry from January 1, 2017 to December 31, 2018. A bivariate analysis was carried out to compare demographic and clinical characteristics in RPS and non-RPS. Short-term mortality risk was analyzed by primary tumor site. The significance of variations in survival by site group was determined using Kaplan-Meier curves and the Log-rank test. Finally, Cox regression was used to assess the hazard ratio for survival by sarcoma group. RPS accounted for 22.8% of the total sample (92 out of 404 cases). The mean age at diagnosis was 67.6 years for RPS vs. 63.4 for non-RPS; 41.3% of RPS were >150 mm vs. 5.5% for non-RPS. Stages III and IV were more prevalent in RPS (53.2 vs. 35.6%), despite the fact that, in both groups, advanced stages are the most common onset at diagnosis. Regarding surgical margins, the present study showed that R0 is the most prevalent in non-RPS (48.7%), while R1-R2 is the most frequent in patients with RPS (39.1%). The 3-year mortality rate for retroperitoneum was 42.9 vs. 25.7%. Comparing RPS and non-RPS, the multivariable Cox model showed a hazard ratio of 1.58 after adjusting for all other prognostic factors. RPS clinical and anatomopathological characteristics differ from those of non-RPS. Overall, despite adjusting for other prognostic factors, the retroperitoneum site was an independent prognostic factor associated with a worse overall survival in sarcoma patients compared with other sites.

Deciding individual treatment for primary retroperitoneal sarcoma

INTRODUCTION

Retroperitoneal sarcomas (RPS) are rare mesenchymal tumors that account for only 0.1-0.2% of all malignancies. Management of this disease is challenging, and resection remains the cornerstone of treatment. Ongoing international collaboration has expanded our knowledge of this disease, allowing for a more personalized approach to RPS patients resulting in improved survival over time. Due to the heterogeneity of RPS, with differing recurrence patterns and sensitivities to neoadjuvant therapies based on histology and grade, management of RPS should be tailored to the individual patient.

AREAS COVERED

Our review focuses on a histology-driven approach in the management of primary RPS. We searched relevant articles from 1993 to 2023 that investigated prognostic factors and treatment of patients with RPS and summarized recent advances and future directions in the field.

EXPERT OPINION

Deeper understanding of the role of neoadjuvant radiotherapy and ongoing trials investigating the role of neoadjuvant chemotherapy will potentially contribute to the development of individualized treatment pathways.

Identification of a clinical web-based nomogram to predict overall survival in elderly retroperitoneal sarcoma patients: A population-based study

The purpose of this study was to develop a web-based nomogram and risk stratification system to predict overall survival (OS) in elderly patients with retroperitoneal sarcoma (RPS). Elderly patients diagnosed with RPS between 2004 and 2015 were identified in the Surveillance, Epidemiology, and End Results (SEER) database. We used univariate and multivariate Cox analysis to identify independent prognostic factors. We plotted the nomogram for predicting the OS of elderly RPS patients at 1, 3, and 5 years by integrating independent prognostic factors. The nomograms were subsequently validated by receiver operating characteristic (ROC) curves, calibration curves, and decision curve analysis (DCA). By calculating the Nomogram score for each patient, we build a risk stratification model to evaluate the survival benefit of elderly RPS patients. A total of 722 elderly RPS patients were included in our study. The nomogram includes 5 clinicopathological variables as independent prognostic factors: age, histological subtype, grade, metastasis status, and surgery. Through the validation, we found that the nomogram has excellent prediction performance. Then web-based nomograms were established. We performed a web-based nomogram and a risk stratification model to assess the prognosis of elderly RPS patients, which are essential for prognostic clustering and decision-making about treatment.

Retroperitoneal Sarcomas: a Current Review on Management

Retroperitoneal sarcomas are heterogeneous tumours with variable disease biology and outcomes. The prognosis is primarily related to tumour histology and grade as well as the ability to achieve margin negative resection. Surgery involves compartment or contiguous organ resection to achieve the above goal. Careful utilization of neoadjuvant and adjuvant strategies like radiotherapy and/or chemotherapy can lead to improvement in margin status, thereby contributing to better local control and possibly reducing systemic dissemination. Use of targeted therapies has paved newer pathways of treatment integration centred on molecular and genetic targets. The aim of this review is to update the reader on all aspects of retroperitoneal sarcoma management including emphasis on pertinent and landmark trials in this regard.

A novel nomogram model to predict the overall survival of patients with retroperitoneal leiomyosarcoma: a large cohort retrospective study

Retroperitoneal leiomyosarcomas (RLS) are the second most common type of retroperitoneal sarcoma and one of the most aggressive tumours. The lack of early warning signs and delay in regular checkups lead to a poor prognosis. This study aims to create a nomogram to predict RLS patients' overall survival (OS). Patients diagnosed with RLS in the Surveillance, Epidemiology, and End Results (SEER) database between 2000 and 2018 were enrolled in this study. First, univariable and multivariable Cox regression analyses were used to identify independent prognostic factors, followed by constructing a nomogram to predict patients' OS at 1, 3, and 5 years. Secondly, the nomogram's distinguishability and prediction accuracy were assessed using receiver operating characteristic (ROC) and calibration curves. Finally, the decision curve analysis (DCA) investigated the nomogram's clinical utility. The study included 305 RLS patients, and they were divided into two groups at random: a training set (216) and a validation set (89). The training set's multivariable Cox regression analysis revealed that surgery, tumour size, tumour grade, and tumour stage were independent prognostic factors. ROC curves demonstrated that the nomogram had a high degree of distinguishability. In the training set, area under the curve (AUC) values for 1, 3, and 5 years were 0.800, 0.806, and 0.788, respectively, while in the validation set, AUC values for 1, 3, and 5 years were 0.738, 0.780, and 0.832, respectively. As evidenced by the calibration curve, the nomogram had high prediction accuracy. Moreover, DCA revealed that the nomogram had high clinical utility. Furthermore, the risk stratification system based on the nomogram could effectively categorise patients into three mortality risk subgroups. Therefore, the developed nomogram and risk stratification system may aid in optimising the treatment decisions of RLS patients to improve treatment prognosis and maximise their healthcare outcomes.

The prognostic factors of primary colorectal sarcoma and the clinical outcomes of negative lymph node dissection

Background

Primary colorectal sarcoma is an extremely rare malignancy that is associated with poor patient outcomes. The aim of this study was to identify the prognostic factors of primary colorectal sarcoma and evaluate the clinical outcomes associated with these prognostic factors.

Methods

Between January 1, 2000 and December 31, 2016, the clinical data of 315 patients with primary colorectal sarcoma were obtained from the Surveillance, Epidemiology, and End Results (SEER) database. Cancer-specific survival (CSS) was analyzed by the Kaplan-Meier method and by log-rank test. The prognostic factors were identified by univariate and multivariate Cox regression analysis and hazard ratio (HR) and 95% confidence interval (CI) of covariates were also estimated. The optimal cutoff value for NLN count at dissection was identified using X-tile software and validated by univariate Cox regression analysis.

Results

Of the 315 patients with primary colorectal sarcoma identified, 88.6% received surgery. The median follow-up time was 34 months with an interquartile range (IQR) of 9-79 months. The 5-year rate of CSS was 76.73% and 27.8% for the surgery group and the non-surgery group, respectively (P<0.0001). Univariate and multivariate Cox regression analysis performed on the data of nonmetastatic patients demonstrated that sex, race, radiotherapy, and chemotherapy had no effect on patient CSS, with age, tumor site, tumor grade, and NLN dissection being independent prognostic factors. A significant correlation was found between advanced age (>80 years old) and poor CSS (HR 1.964; 95% CI: 1.005-3.839; P=0.048). There were also significant correlations between colonic tumors and poor CSS (HR 2.903; 95% CI: 1.348-6.250; P=0.006) and grade IV tumors and poor CSS (HR 3.431; 95% CI: 1.725-6.823; P<0.001), while NLN dissection was associated with improved CSS (HR 0.946; 95% CI: 0.911-0.983; P=0.004). X-tile software analysis was used to determine that the optimal cutoff value for NLN count was 13. Patients who received NLN dissection with a cutoff value of 13 or more displayed better CSS than those who did not (P=0.016).

Conclusions

Primary colorectal sarcoma patients can benefit significantly from primary tumor surgery. Age, tumor site, grade and NLN dissection are independent prognostic factors for CSS in nonmetastatic patients. Importantly, nonmetastatic patients treated with NLN dissection with an NLN count of 13 or more have significantly better CSS.

Retroperitoneal sarcomas: Outcomes of repeated resections

Purpose

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.

Methods

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.

Results

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.

Conclusion

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.

Retroperitoneal tumors: Review of diagnosis and management

Retroperitoneal tumors are extremely rare tumors occurring in the retroperitoneum. Retroperitoneal tumors are divided into benign tumors and malignant tumors, including retroperitoneal sarcoma. Approximately 70-80% of primary retroperitoneal soft-tissue tumors are malignant; however, these only account for 0.1-0.2% of all malignancies. Retroperitoneal sarcoma is an orphan malignant disease with a low incidence. The information on benign retroperitoneal tumors is limited. The American Joint Committee on Cancer/TNM classification updated to the 8th edition in 2017. In 2010, three new drugs for soft tissue sarcoma were approved based on the results of phase III trials, but the histological subtypes of the patients enrolled in the trials of each drug differed. Recently, in addition to surgery for retroperitoneal sarcoma, the effectiveness of perioperative radiation therapy has become interesting. For malignant retroperitoneal tumors and retroperitoneal sarcoma, survival improvement and locoregional recurrence prevention can be undertaken by carrying out surgery to secure negative margins with wide and combined resection of some adjacent organs, and cooperation with a trained medical team comprising of radiologists, pathologists and medical oncologists in centralized hospitals. Some clinical trials aimed at further improving treatment results by adding preoperative chemotherapy and radiation therapy based on histological confirmation using a correct needle biopsy are in progress. In recent years, molecular profiling has been used to select eligible patients for chemotherapy. In the future, precision medicine with next-generation sequencing technology will be expected among the diverse and potential future treatments for retroperitoneal sarcoma. In this review, we summarized the current state of retroperitoneal tumors and retroperitoneal sarcoma.

Retroperitoneal Sarcomas: Prognostic Factors and Outcomes of a Series of Patients Treated at a Single Institution

Retroperitoneal sarcomas (RPS) are rare heterogeneous tumors arising in the retroperitoneum with unique biological and behavioral patterns that are thought to be closely linked to histology. The aim of the study was to audit our results and analyze various clinico-pathological factors including surgical excision, histology, and their implications on the recurrences and survival outcomes in RPS. Retrospective analysis of patients treated at a tertiary referral center in India from March 2008 to July 2017 was performed. The clinico-pathological variables were analyzed for their association with tumor recurrence and survival with special emphasis on histological subtype. The primary outcome was overall survival (OS). One hundred consecutive patients operated for RPS were analyzed. Of these, 27 were operated for recurrent tumors. Liposarcomas (LPS) and leiomyosarcomas (LMS) constituted 50% (n = 50) and 30% (n = 30) of patients respectively. Complete tumor excision was achieved in 83%, with 43% patients undergoing adjacent organ resection. At a median follow-up of 25.3 months, the median disease-free survival (DFS) and overall survival (OS) were 30 months and 87.8 months respectively. On multivariate analysis, tumor grade was the only factor to significantly affect survival (p = 0.001 for DFS and 0.005 for OS). There was no difference in survival outcomes between infiltrative and adhesive tumors with respect to adjacent organ invasion (p = 0.361 for OS). Tumor grade remains an important prognostic factor affecting disease-free and overall survival in retroperitoneal sarcomas irrespective of tumor size, site, and histology.

Outcomes of palliative-intent surgery in retroperitoneal sarcoma-Results from the US Sarcoma Collaborative

BACKGROUND AND OBJECTIVES

Outcomes of palliative-intent surgery in retroperitoneal sarcomas (RPS) are not well understood. This study aims to define indications for and outcomes after palliative-intent RPS resection.

METHODS

Using a retrospective 8-institution database, patients undergoing resection of primary/recurrent RPS with palliative intent were identified. Logistic regression and Cox-proportional hazards models were constructed to analyze factors associated with postoperative complications and overall survival (OS).

RESULTS

Of 3088 patients, 70 underwent 87 palliative-intent procedures. Most common indications were pain (26%) and bowel obstruction (21%). Dedifferentiated liposarcoma (n = 17, 24%), leiomyosarcoma (n = 13, 19%) were predominant subtypes. Median OS was 10.69 months (IQR, 3.91-23.23). R2 resection (OR, 8.60; CI, 1.42-52.15; P = .019), larger tumors (OR, 10.87; CI, 1.44-82.11; P = .021) and low preoperative albumin (OR, 0.14; CI, 0.04-0.57; P = .006) were associated with postoperative complications. Postoperative complications (HR, 1.95; CI, 1.02-3.71; P = .043) and high-grade histology (HR, 6.56; CI, 1.72-25.05; P = .006) rather than resection status were associated with reduced OS. However, in R2-resected patients, development of postoperative complications significantly reduced survival (P = .042).

CONCLUSIONS

Postoperative complications and high-grade histology rather than resection status impacts survival in palliative-intent RPS resections. Given the higher incidence of postoperative complications which may diminish survival, palliative-intent R2 resection should be offered only after cautious consideration.

An Evaluation of the Eighth Edition of the American Joint Committee on Cancer (AJCC) Staging System for Retroperitoneal Sarcomas Using the National Cancer Data Base (NCDB): Does Size Matter?

OBJECTIVES

Retroperitoneal sarcomas (RPS) are often large at diagnosis calling into question the seventh edition AJCC size classification of <5 cm (T1) or ≥5 cm (T2). The eighth edition expands T stage into 4 categories (T1: ≤5 cm, T2: 5<x≤10 cm, T3: 10<x≤15 cm, T4: >15 cm). We evaluated the prognostic ability of the eighth edition using the National Cancer Database (NCDB).

METHODS

Patients with RPS treated between 1998 and 2011 were identified from the NCDB; overall survival (OS) was compared.

RESULTS

Of the 6427 patients identified, 9% had tumors ≤5 cm (n=580), 19.4% 5<x≤10 cm (n=1246), 20.2% 10<x≤15 cm (n=1298) and 47.4% >15 cm (n=3045). With the eighth edition, stage II patients (G2/3 ≤5 cm) have a similar OS to stage IIIA patients (G2/3 5 cm<x≤10 cm), and patients with larger tumors (stage IIIB, G2/3>10 cm) show a decrease in OS. Tumor size as a continuous variable had a modest effect on survival (HR, 1.004; P=0.04). On multivariate analysis, higher T-stage was associated with decreased OS (T4 HR, 1.3; P<0.001) but high grade and incomplete resection (R2) were stronger prognostic factors. The c-index for both editions were similar (80.13 eighth vs. 80.08 seventh).

CONCLUSIONS

The eighth edition AJCC staging system for retroperitoneal sarcoma incorporates larger tumor size parameters that better characterize most patients, but tumor size alone is only a modest predictor of outcome.

Analysis of outcomes and predictors of long-term survival following resection for retroperitoneal sarcoma

BACKGROUND

Retroperitoneal sarcomas (RPS) include a heterogeneous group of rare malignant tumours, and various treatment algorithms are still controversially discussed until today. The present study aimed to examine postoperative and long-term outcomes after resection of primary RPS.

PATIENTS AND METHODS

Clinicopathological data of patients who underwent resection of primary RPS between 2005 and 2015 were assessed, and predictors for overall survival (OS) and disease-free survival (DFS) were identified.

RESULTS

Sixty-one patients underwent resection for primary RPS. Postoperative morbidity and mortality rates were 31 and 3%, respectively. After a median follow-up time of 74 months, 5-year OS and DFS rates were 58 and 34%, respectively. Histologic high grade (5-year OS: G1: 92% vs. G2: 54% vs. G3: 43%, P = 0.030) was significantly associated with diminished OS in univariate and multivariate analyses. When assessing DFS, histologic high grade (5-year DFS: G1: 63% vs. G2: 24% vs. G3: 22%, P = 0.013), positive surgical resection margins (5-year DFS: R0: 53% vs. R1: 10% vs. R2: 0%, P = 0.014), and vascular involvement (5-year DFS: yes: 33% vs no: 39%, P = 0.001), were significantly associated with inferior DFS in univariate and multivariate analyses.

CONCLUSIONS

High-grade tumours indicated poor OS, while vascular involvement, positive surgical resection margins, and histologic grade are the most important predictors of DFS. Although multimodal treatment strategies are progressively established, surgical resection remains the mainstay in the majority of patients with RPS, even in cases with vascular involvement.

Predictors of Disease-Free and Overall Survival in Retroperitoneal Sarcomas: A Modern 16-Year Multi-Institutional Study from the United States Sarcoma Collaboration (USSC)

Background

Retroperitoneal sarcomas (RPS) comprise approximately 15% of all soft-tissue sarcomas and frequently associated with significant morbidity and as little as 30% 5-year survival. Here, we provide a large, contemporary, and multi-institutional experience to determine which tumor, patient, and treatment characteristics are associated with long-term outcomes in RPS.

Methods

571 patients with primary RPS were identified from the United States Sarcoma Collaboration (USSC). RPS patients who underwent resection from January 2000 to April 2016 were included with patient, tumor, and treatment-specific variables investigated as independent predictors of survival. Survival analyses for disease-free and overall survival were conducted using Kaplan–Meier and Cox proportional hazards model methods.

Results

The study cohort was 55% female, with a median age of 58.9 years (IQR: 48.6–70.0). The most common tumor histiotypes were liposarcoma (34%) and leiomyosarcoma (28%). Median follow-up was 30.6 months (IQR: 11.2–60.4). Median disease-free survival was 35.3 months (95% CI: 27.6–43.0), with multivariate predictors of poorer disease-free survival including higher grade tumors, nodal-positive disease, and multivisceral resection. Median overall survival was 81.6 months (95% CI: 66.3–96.8). Multivariate predictors of shorter overall survival included higher grade tumors, nodal-positive and multifocal disease, systemic chemotherapy, and grossly positive margins (R2) following resection.

Conclusions

The strongest predictors of disease-free and overall survival are tumor-specific characteristics, while surgical factors are less impactful. Nonsurgical therapies are not associated with improved outcomes despite persistent interest and utilization. Complete macroscopic resection (R0/R1) remains a persistent potentially modifiable risk factor associated with improved overall survival in patients with retroperitoneal sarcomas.

A systematic review of population-based studies examining outcomes in primary retroperitoneal sarcoma surgery

Retroperitoneal sarcomas (RPS) are rare mesenchymal tumours. Their rarity challenges our ability to understand expected outcomes. The aim of this systematic review was to examine 30-day morbidity and mortality, overall survival rates and prognostic predictors from population-based studies for patients undergoing curative resection for primary RPS. A systematic literature review of EMBASE, MEDLINE, PUBMED and the Cochrane library was performed using PRISMA for population-based studies reporting from nationally registered databases on primary RPS surgical resections in adults. The main outcomes evaluated were 30-day morbidity and mortality and overall survival rates. The use of additional treatment modalities and predictors of overall survival were also examined. Fourteen studies (n = 12 834 patients) reporting from 3 national databases, (Surveillance, Epidemiology and End Results (SEER), the United States National Cancer Database (US NCDB) and the American College of Surgeons' National Surgical Quality Improvement Program (ACS NSQIP)) were analysed. The reported overall 30-day morbidity and mortality were 23% (n = 191/846) and 3% (n = 278/10 181) respectively. Reported use of perioperative radiotherapy was 28%. No study reported loco-regional recurrence rates. Overall reported 5-year survival ranged from 52% to 62%. Independent predictors of overall survival were age of the patient, resection margin, tumour grade and size, histological subtype and receipt of radiotherapy. This review of population-based data demonstrated relatively low 30-day morbidity rates in patients undergoing curative surgical resections for primary RPS. Thirty-day mortality rates were similar to other abdominal tumour groups. There remains a paucity of data reporting recurrence rates, however 5-year survival rates ranged from 52 to 62%.

Radiation Therapy for Retroperitoneal Sarcomas: Influences of Histology, Grade, and Size

Perioperative radiation therapy (RT) has been associated with reduced local recurrence in patients with retroperitoneal sarcomas (RPS); however, selection criteria remain unclear. We hypothesized that perioperative RT would improve survival in patients with RPS and would be associated with pathological factors. The National Cancer Database (NCDB) from 2004 to 2012 was reviewed for patients with nonmetastatic RPS undergoing curative intent resection. Tumor size was dichotomized at 15 cm based on 8th edition American Joint Committee on Cancer (AJCC) staging. Patients with the highest comorbidity score were excluded. Unadjusted Kaplan–Meier and adjusted Cox proportional hazards modeling analyzed overall survival (OS). Multivariable logistic regression modeled margin positivity. A total of 2,264 patients were included; 727 patients (32.1%) had perioperative radiation in whom 203 (9.0%) had radiation preoperatively. Median (IQR) RPS size was 17.5 [11.0–27.0] cm. Histopathology was high grade in 1048 patients (43.7%). Multivariable analysis revealed that perioperative radiation was independently associated with decreased mortality (HR 0.72, 95% confidence intervals (CIs) 0.62–0.84, p < 0.001), and preoperative RT was associated with reduced margin positivity (HR 0.72, 95% CI 0.53–0.97, p=0.032). Stratified survival analysis showed that radiation was associated with prolonged median OS for RPS that were high-grade (64.3 vs. 43.6 months, p < 0.001), less than 15 cm (104.1 vs. 84.2 months, p=0.007), and leiomyosarcomatous (104.8 vs. 61.8 months, p < 0.001). Perioperative radiation is independently associated with decreased mortality in patients with high-grade, less than 15 cm, and leiomyosarcomatous tumors. Preoperative radiation is independently associated with margin-negative resection. These data support the selective use of perioperative radiation in the multidisciplinary management of RPS.

Did outcomes improve in retroperitoneal sarcoma surgery?

In the last decades, the deeper understanding of the biological basis of the disease, along with the advances of surgical techniques and oncologic multimodal treatments, have led to an overall increase of survival of cancer patients. However, significant amelioration of the prognosis of rare and under-investigated tumors such as soft tissue sarcoma is less evident. In this review, main changes in the surgical management of retroperitoneal sarcoma (RPS) are discussed in order to figure out whether actual improvement in RPS outcome has been occurred in the last years.

The influence of anatomic location on outcomes in patients with localized primary soft tissue sarcoma

Background

We hypothesized that survival varied significantly between retroperitoneal soft tissue sarcoma (STS) and extremity/trunk STS. This study explored the reasons for the different outcomes and identified patient characteristics for survival.

Methods

This retrospective study identified 213 consecutive patients with localized primary STS from January 2002 to July 2013, including 47 retroperitoneal STS (22.1%) and 166 extremity/trunk STS (77.9%). Local failure-free survival (LFFS), distant metastasis-free survival (DMFS) and overall survival (OS) were constructed by the Kaplan-Meier method. Univariate Cox proportional hazards regression models were fit to assess the ability of patient characteristics to predict survival.

Results

At presentation, patients with retroperitoneal STS had larger tumor size (median size 18 cm vs. 6 cm; P < 0.001) and positive margin (21.3% vs. 8.4%; P = 0.014), and less often received radiotherapy (2.1% vs. 45.8%; P < 0.001). The median follow-up time for the entire population was 68 months (range, 5-127 months). Local recurrence was more frequent in patients with retroperitoneal STS compared with patients with extremity/trunk STS (53.2% vs. 28.3%; P = 0.001). LFFS and OS were lower in patients with retroperitoneal STS than extremity/trunk STS, with 5-year LFFS (50% vs. 74.3%; P < 0.001) and 5-year OS (65.4% vs. 77.5%; P = 0.017), respectively.

Conclusion

Retroperitoneal STS was associated with significantly worse survival compared with extremity/trunk STS. Larger tumor size, more patients with positive margin and fewer patients received radiotherapy in retroperitoneal group may result in worse survival compared with extremity/trunk disease.

Surgically Treated Retroperitoneal Sarcoma: A Population-based Competing Risks Analysis

BACKGROUND

Data regarding the relationship between non-disease-specific (NDSM) and disease-specific mortality (DSM) in patients with surgically treated nonmetastatic retroperitoneal sarcoma (nmRPS) are lacking.

OBJECTIVE

To examine the rates of NDSM and DSM among patients with surgically treated nmRPS.

DESIGN, SETTING AND PARTICIPANTS

We used the Surveillance, Epidemiology and End Results (SEER) database (2004-2014) to obtain data for patients with surgically treated nonmetastatic RPS.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSES

The 5-yr DSM and NDSM rates were generated via competing risks regression (CRR) methodologies. Multivariable CRR models were used to test the effects of age, histologic subtype, grade, size, and radiotherapy (RT) status on NDSM and DSM.

RESULTS AND LIMITATIONS

Overall, 231 (26.8%) and 57 patients (6.7%) died from DSM and NDSM, respectively. Following stratification according to age, histologic subtype, grade, size, and RT status, the proportion of patients who succumbed to NDSM was higher for patients with age above the median, liposarcoma histologic subtype, low grade, and tumor size ≥17cm. DSM rates were also higher among patients with age above the median, leiomyosarcoma histologic subtype, high grade, and tumor size ≥17cm. Multivariable CRR models revealed that age above the median was associated with higher NDSM (hazard ratio [HR]1.7, 95% confidence interval [CI] 1.1-2.7; p=0.019). Conversely, leiomyosarcoma (HR 1.9, 95% CI 1.4-2.6; p<0.0001), sarcoma not otherwise specified (HR 2.4, 95% CI 1.5-3.8; p<0.0001) and other RPS (HR 2, 95% CI 1.2-3.4; p=0.01) histologic subtypes, high grade (HR 3, 95% CI 2.3-4; p<0.0001), and tumor size above the median (HR 1.4, 95% CI 1.1-3.8; p=0.012) were associated with higher DSM. This is a retrospective study and misclassification bias may be present because of the reliability of the distinction between DSM and NDSM.

CONCLUSIONS

The impact of NDSM in surgically treated nmRPS is not trivial, particularly among patients with favorable characteristics such as liposarcoma histologic subtype and low-grade tumors.

PATIENT SUMMARY

Mortality from causes not related to the specific disease is important in patients with retroperitoneal sarcoma (RPS) treated surgically. In particular, patients with good tumor characteristics, namely liposarcoma histologic subtype and low grade, most often do not die from their cancer but succumb to causes other than RPS. Unfortunately, tumor characteristics and radiotherapy administration shed relatively little light on predicting mortality from causes other than cancer in patients with surgically treated RPS. Our report compares the risk of dying from RPS with that of dying from other causes according to the type of surgically treated sarcoma.

Minimally Invasive Versus Open Primary Resection for Retroperitoneal Soft Tissue Sarcoma: A Propensity-Matched Study From the National Cancer Database

BACKGROUND

Although well described for gastrointestinal and pelvic cancers, use of minimally invasive surgery (MIS) for the management of retroperitoneal soft tissue sarcoma (RPS) remains unknown. The current study aimed to describe patterns of MIS use and assess the association between MIS and clinical outcomes among patients undergoing surgery for RPS.

METHODS

Patients undergoing a primary resection for RPS between 2010 and 2014 were identified using the National Cancer Database. Multivariable logistic and Cox proportional hazards models were used to assess the association between use of MIS and clinical outcomes. Sensitivity analysis was performed using propensity score-matching (PSM).

RESULTS

This study identified 3844 patients who met the inclusion criteria. Of these patients, 89.3% (n = 3432) underwent an open surgery, whereas 10.7% (n = 412) underwent MIS. The patients undergoing MIS were more likely to present with smaller tumors (open vs MIS: median tumor size, 17 cm; interquartile range [IQR, 9.8-26.0] vs 10.5 cm [IQR, 6.5-18.0]) and to undergo surgery at community hospitals (26.8% vs 36.1%; both P < 0.001). Although MIS was associated with a shorter hospital length of stay [LOS] (median LOS, 6 days [IQR, 5-9 days] vs 4 days [IQR, 2-7]; P < 0.001), postoperative mortality and overall survival were comparable between the two treatment groups (all P > 0.05). These findings were confirmed using PSM.

CONCLUSIONS

MIS was associated with a shorter LOS, however, postoperative mortality and overall survival were comparable by operative approach. Future research is required to evaluate the use of MIS for the management of RPS. Policies are required to ensure that patients receive care in accordance with best practices and recommended guidelines.

Intensity modulated radiation therapy and surgery for Management of Retroperitoneal Sarcomas: a single-institution experience

BACKGROUND

Peri-operative radiation of retroperitoneal sarcomas (RPS) is an important component of multidisciplinary treatment. All retrospective series thus far included patients treated with older radiation therapy (RT) techniques including 2D and 3DRT. Intensity modulated radiation therapy (IMRT) allows for selective dose escalation while sparing adjacent organs. We therefore report the first series of patients with RPS treated solely with IMRT, surgery and chemotherapy. We hypothesized that IMRT would permit safe dose escalation and superior rates of local control (LC) in this high-risk patient population.

METHODS

Thirty patients with RPS treated with curative intent between 2006 and 2015 were included in this retrospective study. RT was administered either pre- or post-operatively and IMRT was used in all patients. Statistical comparisons, LC, distant metastasis (DM), and overall survival (OS) were calculated by Kaplan-Meier analysis and univariate Cox regression.

RESULTS

Median follow-up time after completion of RT was 36 months (range 1.4-112). Median tumor size was 14 cm (range 3.6 - 28 cm). The most prevalent histologies were liposarcoma in 10 (33%) patients and leiomyosarcoma in 10 (33%) with 21 patients (70%) having high-grade disease. Twenty-eight (93%) patients had surgical resection with 47% having positive margins. Chemotherapy was administered in 9 (30%) patients. RT was delivered pre-operatively in 11 (37%) patients, and post-operatively in 19 (63%) with 60% of patients receiving a simultaneous integrated boost. Pre-operative median RT dose to the high-risk area was 55 Gy (range, 43-66 Gy) while median post-operative dose was 60.4 Gy (range, 45-66.6 Gy). There was one acute grade 3 and one late grade 3 toxicity and no grade 4 or 5 toxicities. Three year actuarial LC, freedom from DM, and OS rates were 84%, 64%, and 68% respectively. Positive surgical margins were associated with a higher risk of local recurrence (p = 0.02) and decreased OS (p = 0.04). Pre-operative RT was associated with improved LC (p = 0.1) with a 5-year actuarial LC of 100%. Administration of chemotherapy, timing of RT, histology or grade was not predictive of OS.

CONCLUSIONS

Patients with RPS treated with peri-operative IMRT at our institution had excellent local control and low incidences of toxicity.