Concomitant organ resection does not improve outcomes in primary retroperitoneal well-differentiated liposarcoma: A retrospective cohort study at a major sarcoma center

Diagnosis and management of dedifferentiated liposarcoma: A multidisciplinary position statement

Dedifferentiated liposarcoma (DDLPS) is a malignant mesenchymal neoplasm in desperate need of novel therapeutic approaches. Often occurring in conjunction with well-differentiated liposarcoma (WDLPS), DDLPS can behave more aggressively and exhibits a significant risk for developing recurrence or metastatic disease when compared to its well-differentiated counterpart. A multidisciplinary approach is critically important, particularly for patients with localized disease, as disease presentations are often complex, and the management of patients has become increasingly nuanced as treatment approaches have become more refined. Expert pathology review and appropriate application of diagnostic molecular techniques are key components of DDLPS diagnosis and also reflect an improved understanding of the underlying pathogenesis of the disease. Systemic therapies remain limited for DDLPS, but novel therapies targeting important underlying molecular drivers have resulted in ongoing clinical trials aiming to improve outcomes for patients with advanced disease. In recognition of the increased activity and interest within the DDLPS field, a multidisciplinary group of nationally recognized experts in medical oncology, surgical oncology, radiation oncology, and pathology was convened to summarize key insights. This position paper highlights important points from the meeting and provides evidence-based recommendations for practicing clinicians.

Clinical features and surgical strategy of retroperitoneal liposarcoma involving the kidney capsule: a retrospective comparative cohort study

BACKGROUND

Valid and generalizable data on the clinical features and surgical strategies for retroperitoneal liposarcoma (LPS) involving the kidney capsule remain scarce. This study aimed to investigate the clinical characteristics, morbidity, mortality, and long-term survival of patients with retroperitoneal LPS involving the kidney capsule.

METHODS

The authors analyzed a prospectively maintained database of patients who underwent surgical resection for retroperitoneal LPS between 2015 and 2020. The patients were categorized into kidney capsule or no kidney capsule groups based on the presence or absence of kidney capsule involvement. A kidney-sparing strategy for retroperitoneal LPS involving the kidney capsule was developed. The primary outcome measure was overall survival (OS). The cumulative event probability curve was estimated using the Kaplan-Meier, and differences between groups using the Log-Rank.

RESULTS

The study population consisted of 128 patients-54 with and 74 without kidney capsule involvement. Of these patients, 70 were female (54.7%) and 58 were male (45.3%), with a median age of 55. The median follow-up duration was 35 months. Postoperative morbidity, mortality, length of hospital stay, length of ICU stay, OS, and recurrence-free survival (RFS) did not differ significantly between the groups. Eleven patients developed postoperative acute kidney injury (AKI), and one patient required dialysis during the follow-up period. In multivariable logistic regression analysis, only nephrectomy was independently associated with postoperative AKI. Subgroup analysis of patients with kidney capsule involvement showed that nephrectomy did not improve OS or RFS but significantly decreased postoperative estimated glomerular filtration rate.

CONCLUSION

Nephrectomy was associated with an increased risk of postoperative AKI after retroperitoneal LPS resection. A kidney-sparing strategy for retroperitoneal LPS involving the kidney capsule achieved optimal clinical outcomes.

Comparing Multivisceral Resection with Tumor-only Resection of Liposarcoma Using the Win Ratio

BACKGROUND

Multivisceral resection of retroperitoneal liposarcoma (LPS) is associated with increased morbidity and may not confer a survival benefit compared with tumor-only (TO) resection. We compared both approaches using a novel statistical method called the "win ratio" (WR).

METHODS

Patients who underwent resection of LPS from 2004 to 2015 were identified from the National Cancer Database. Multivisceral resection was defined as removal of the primary site in addition to other organs. The WR was calculated based on a hierarchy of postoperative outcomes: 30-day and 90-day mortality, long-term survival, and severe complication.

RESULTS

Among 958 patients (multivisceral 634, TO 324) who underwent resection, the median age was 63 years (interquartile range [IQR] 54-71) with a median follow-up of 51 months (IQR 30-86). There was no difference in the WR among patients who underwent TO versus multivisceral resection in the matched cohort (WR 0.82, 95% confidence interval [CI] 0.61-1.10). In patients aged 72-90 years, those who underwent multivisceral resection had 36% lower odds of winning compared with patients undergoing TO resection (WR 0.64, 95% CI 0.40-0.98). A subgroup analysis of patients classified as not having adjacent tumor involvement at the time of surgery revealed that those patients who underwent multivisceral resection had 33% lower odds of winning compared to TO resection (WR 0.67, 95% CI 0.45-0.99).

CONCLUSIONS

Based on win-ratio assessments of a hierarchical composite endpoint, multivisceral resection in patients without adjacent tumor involvement may not confer improved outcomes. This method supports the rationale for less invasive resection of LPS in select patients, especially older patients.

Aggressive surgical approach with vascular resection and reconstruction for retroperitoneal sarcomas: a systematic review

BACKGROUND AND AIM

Surgery is the mainstay of treatment and completeness of surgical resection is critical to achieve local control for retroperitoneal sarcoma (RPS). En-bloc resection of adjacent organs, including major abdominal vessels, is often required to achieve negative margins. The aim of this review was to summarise the available evidence to assess the relative benefits and disadvantages of an aggressive surgical approach with vascular resection in patients with retroperitoneal sarcoma (RPS).

METHODS

We searched PubMed, the Cochrane Library, and EMBASE for relevant studies published from inception up to August 1, 2022. We performed a systematic review of the available studies to assess the safety and long-term survival results of vascular resection for RPS.

RESULTS

We identified a total of 23 studies for our review. Overall postoperative in-hospital or 30-day mortality rate of patients with primary iliocaval leiomyosarcoma was 3% (11/359), and the major complication rate was 13%. The recurrence-free survival (RFS) rates after the follow-up period varied between 15% and 52%, and the 5-year overall survival (OS) rates ranged from 25 to 78%. Overall postoperative in-hospital or 30-day mortality rate of patients with RPSs receiving vascular resection was 3%, and the major complication rate was 27%. The RFS rates after the follow-up period were 18-86%, and the 5-year OS rates varied between 50% and 73%. There were no significant differences in the rates of RFS (HR: 0.97; 95% CI: 0.74-1.19; p = 0.945) and OS (HR: 1.01; 95% CI: 0.66-1.36; p = 0.774) between the extended resection group and tumour resection alone group.

CONCLUSIONS

With adequate preparation and proper management, for patients with RPSs involving major vessels, aggressive surgical approach with vascular resection can achieve R0/R1 resection and improve survival.

Case Report: Giant paratesticular liposarcoma was resected and refused radical orchiectomy

Paratesticular liposarcoma (PLS) causes scrotal mass changes, rarely in the urinary system. Before surgery, PLS causes scrotal mass changes that are difficult to distinguish from other causes. There has been a report of a giant paratestis liposarcoma resection and refusal to undergo orchiectomy. A 65-year-old man presented with finding the left scrotal mass after 2 years. Physical examination showed that the left scrotal mass was obviously difficult to retract. Pelvic CT showed that the left scrotal mass and flaky fat density shadow accompanied with left inguinal hernia. During surgery, laparoscopic exploration was performed to rule out inguinal hernia, and a scrotal exploration was also performed concurrently. The intraoperative frozen pathology considered lipogenic tumor, and the patient's wife refused to undergo simultaneous left radical orchiectomy. Later the mass was completely removed, and postoperative pathology confirmed paratestis liposarcoma. During a 15-month routine follow-up, the tumor did not recur locally or metastasize distantly. PLS should be focused on early diagnosis and treatment, preoperative examinations and postoperative pathology should be combined, and highly personalized treatment will be implemented.

Short- and long-term surgical outcomes of pancreatic resection for retroperitoneal sarcoma: A long-term single-center experience of 90 cases

BACKGROUND AND OBJECTIVES

Resection of retroperitoneal sarcoma (RPS) en bloc with pancreas is challenging and controversial. This single-center retrospective study aimed to analyze the impact of pancreatic resection (PR) and its different types on short- and long-term outcomes in patients with RPS.

METHODS

Data from 242 consecutive patients with RPS who underwent surgical treatment at the Peking University Cancer Hospital Sarcoma Center between January 2010 and February 2021 were analyzed. Out of these, 90 patients underwent PR, including pancreaticoduodenectomy (PD) in 31 and distal pancreatectomy (DP) in 59.

RESULTS

Patients in the PR group had a higher major morbidity (37.8% vs. 14.5%) and mortality (8.9% vs. 1.3%) than those in the non-PR group, with a similar 5-year overall survival (OS) rate (46.9% vs. 53.6%). Patients in the PD and DP groups had a slight difference in major morbidity (48.4% vs. 32.2%), mortality (6.4% vs. 10.2%), and 5-year OS rates (43.3% vs. 49.3%). The PR type was not an independent risk factor for major morbidity or OS.

CONCLUSIONS

PR in RPS resection was associated with increased morbidity and mortality with minimal influence on survival. Patients with RPS undergoing PD and DP showed slight differences in terms of safety and OS.

Tumor grade and symptoms at presentation are survival risk factors in Chinese patients with primary retroperitoneal sarcoma

Background and Aim

No cohort studies have been performed on Chinese primary retroperitoneal sarcoma (RPS) patients. Data derived from western cohort studies may not be directly superimposable on Asian counterparts. Furthermore, the risk factors for survival of RPS are currently unknown for Chinese patients. The objectives were therefore to (1) gain insight into RPS incidence and patient demographics and clinical details; (2) determine the risk factors for overall survival (OS) and disease-free survival (DFS); and (3) critically appraise the Asian cohort data in relation to information obtained in western cohort studies.

Methods

In this retrospective cohort study, the health records of patients that had been diagnosed with primary localized RPS with curative intent between 2009 and 2020 were analyzed. Cox proportional hazards analysis was conducted to evaluate the risk factors for OS and DFS.

Results

A total of 261 patients met the inclusion criteria. Ninety-six (36.8%) patients had been diagnosed with well-differentiated liposarcoma, 63 patients (24.1%) with dedifferentiated liposarcoma, 41 patients (15.7%) with leiomyosarcoma (LMS), 22 patients (8.4%) with solitary fibroma, 7 patients (2.7%) with malignant peripheral nerve sheath tumor (MPNST), and 32 patients (12.3%) with another type of RPS. The study further revealed that (1) the 5-y OS and DFS in RPS patients was 67.8% and 51.3%, respectively, with the highest OS and DFS observed in MPNST (100% and 100%, respectively) and the lowest 5-y OS and DFS attributed to LMS (42.6% and 28.9%, respectively); (2) symptoms at presentation, Federal National Cancer Center (FNCLCC) grade, and number of combined resections are independent risk factors in OS; (3) symptoms at presentation, FNCLCC grade, chemotherapy, and hospital length of stay are independent risk factors for DFS; and (4) patients at high risk (symptoms at presentation and high-grade tumors) have less than half the chance of survival at 5 y post-diagnosis than patients with a low-risk profile.

Conclusions

Symptoms at presentation constitute a risk factor for OS and DFS. When combined with tumor grade - another risk factor for both OS and DFS - patients can be classified into a high-risk and low-risk category to gauge a patient's prognosis and, accordingly, frame an optimal clinical trajectory. Moreover, the clinicopathology and overall prognosis of RPS in Asian and Western populations are comparable and hence superimposable.

Relevance for Patients

The present study identifies the risk factors of survival in RPS and suggests symptoms at presentation should be considered in the preoperative consultation and added in prognostic grouping.

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

BACKGROUND AND OBJECTIVES

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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

Background

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.

Methods

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).

Findings

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.

Conclusions

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.

Surgery of resectable local recurrence following colorectal cancer: Compartmental surgery improves local control

BACKGROUND

This study aims to identify prognostic factors and define the best extent of surgery for optimizing treatment of local recurrence (LR) following colorectal cancer (CRC).

METHODS

An institutional database of consecutive patients who underwent radical resection (R0/R1) of LR following CRC was analyzed prospectively from 2010 to 2021 at one tertiary cancer center.

RESULTS

In this study, 75 patients were included with LR following CRC and analyzed. Patients were categorized as compartmental resections (CompRe) (n = 47) if all adjacent organs were systematically removed, with or without tumor involvement, or noncompartmental resections (NoCompRe) (n = 28) if only contiguously involved organs were resected. NoCompRe were mainly related to contact between major vessels or bone and the tumor, with only 8/19 (42.1%) resections. Five-year overall survival and locoregional-free survival were 37.5% and 38.8% respectively. Local control was better in the CompRe than the NocompRe group (61.4% vs. 11%; p < 0.01). CompRe (hazard ratio: 2.34 [1.16-4.68]; p = 0.017) and absence of peritoneal metastasis (3.05 [1.03-9.02]; p = 0.044) were the two factors associated with decreased abdominal recurrences in multivariate analysis.

CONCLUSION

Complete compartmental surgery is safe and improves local control. Optimal LR resection needs to remove all contiguous organs, with or without tumor involvement.

Retroperitoneal and Mesenteric Liposarcomas

Retroperitoneal liposarcomas are a rare entity and are comprised mostly of the well-differentiated and dedifferentiated subtypes. Eight-year survival ranges from 30% to 80% depending on histologic subtype and grade. Surgery is the cornerstone of treatment and compartment resection is the current standard. Mesenteric liposarcomas are extremely rare and comprise more high-grade lesions, with poorer prognosis of 50% 5-year overall survival. They are managed with a similar aggressive surgical approach. This review presents the current management of retroperitoneal and mesenteric liposarcomas.

A long-term survivor of advanced retroperitoneal dedifferentiated liposarcoma: a successful multimodal approach with extended resection and chemotherapy

Surgical resection is the mainstay of treatment for retroperitoneal liposarcoma (RPLS). Herein, we describe a case of dedifferentiated RPLS successfully treated with an extended surgical approach with adjuvant chemotherapy. A 61-year-old male was referred to our hospital with a chief complaint of chest tightness. Abdominal computed tomography revealed a large retroperitoneal tumor, 11 cm in diameter, extensively invading the surrounding organs: the celiac axis, the splenic artery, the pancreatic body and tail, the lesser curvature of the stomach and the left adrenal gland. Endoscopic ultrasound-guided fine-needle aspiration biopsy confirmed dedifferentiated liposarcoma, suggesting aggressive tumor biology. We performed total gastrectomy combined with distal pancreatectomy with celiac axis and left adrenal gland resection with a curative intent. The postoperative course was almost uneventful. As the pathological findings indicated a positive margin with a well-differentiated liposarcoma component, we added adjuvant chemotherapy with four cycles of doxorubicin and ifosfamide (AI). Five years after primary surgery, regular follow-up CT demonstrated a pulmonary hilar lymph node enlargement and a tumor at paraesophageal locations. After downsizing chemotherapy with eribulin followed by pazopanib, he underwent partial esophagectomy with dissection of the paraesophageal tumor. The pathological findings indicated recurrence of dedifferentiated liposarcoma with a tumor-free surgical margin. He is currently alive without any evidence of recurrence almost 7 years after the first surgery and 15 months after the second surgery. The long-term survival gained in this patient indicates that extended resections and adjuvant chemotherapy could prolong survival in patients even with RPLS with dedifferentiated tumor histology.

Case report: Two cases of primary paratesticular liposarcoma

Paratesticular liposarcoma is a sporadic urological tumor. We report the clinical presentation, treatment course, and prognosis of 2 cases of primary paratesticular liposarcoma with different pathological types, with the aim of further understanding the diagnosis and treatment of this rare disease. Case 1 was a 53-years-old male patient who presented with left scrotal enlargement with swelling 3 years ago and was considered to have a testicular malignancy on preoperative CT scan and enhanced MRI. The patient underwent resection of the left scrotal mass and left orchiectomy under general anaesthesia. Histopathological study confirmed the diagnosis of dedifferentiated liposarcoma. At the 4-months follow-up, no local recurrence or distant metastasis was observed. Case 2 is a 42-years-old male patient with a left scrotal mass which was discovered six months ago. Preoperatively, he underwent CT plain and enhanced MRI examinations suggesting an intra-scrotal occupancy. The patient underwent scrotoscopic excision of the left scrotal mass under general anesthesia. Histopathological studies confirmed the diagnosis of highly differentiated liposarcoma. At the 10-months follow-up, no local recurrence or distant metastasis was observed. Preoperative differential diagnosis of paratesticular liposarcoma should be noted with testicular tumor and extra-abdominal hernia. Extensive local excision and, if necessary, concomitant radical testicular resection is the treatment of choice. If the tumor in the scrotum spreads to the inguinal region, surgical removal with the aid of a scrotoscope may be attempted. This procedure avoids the formation of a large incision in the inguinal region compared to traditional open surgery. Patients commonly experience local recurrence and less distant metastases after surgery, so long-term follow-up is recommended.

National Trends in Treatment for Retroperitoneal Soft Tissue Sarcoma: A Modern Appraisal of Variability in Therapeutic Strategies

BACKGROUND

Little level 1 evidence exists to guide multimodality treatment in retroperitoneal soft tissue sarcoma (RPS), which may lead to significant variation in therapeutic approaches. This analysis aimed to describe national RPS treatment trends and explore potential variability among low-/high-volume hospitals (LVH/HVHs).

PATIENTS AND METHODS

In total, 5992 patients who underwent resection for primary RPS were retrospectively identified in the National Cancer Database (2004-2017). Time trend analyses examined rates of multivisceral resection (MVR), radiation, and chemotherapy use. LVHs were defined as those carrying out fewer than ten resections per year (N = 5433), whereas HVHs were defined as those carrying out ten or more (N = 559). Descriptive statistics and logistic regression models compared trends between groups.

RESULTS

MVR was more frequent at HVHs (63.7% versus 43.5%, p < 0.001). Use of radiation varied widely by hospital volume. HVHs more frequently employed preoperative radiation as compared with LVHs (14.7% versus 8.1%, p < 0.001). Throughout the study period, LVHs increased utilization of preoperative radiation (2.6% to 12.0%, p < 0.001) whereas rates at HVHs remained stable. Overall, LVHs utilized postoperative radiation significantly more frequently as compared with HVHs (14.7% versus 2.7%, respectively, p < 0.001). Postoperative radiation at LVHs remained stable until 2013 and sharply declined thereafter (16.7% to 6.9%, p < 0.001). Rates of postoperative radiation use at HVHs remained lower than those at LVHs at all time points.

CONCLUSIONS

Strategies for resection and radiation use at LVHs have trended towards those of HVHs. Current national implementation of preoperative radiation, MVR, and chemotherapy remains heterogeneous. These findings inform future trial design and support standardization of care.

[Retroperitoneal soft tissue sarcoma: surgical management]

BACKGROUND

Retroperitoneal soft tissue sarcomas are rare and heterogeneous tumors with high recurrence rates that require a multimodal treatment approach and a surgical resection strategy adapted to tumor localization and histological subtype.

OBJECTIVE

Based on current scientific data this article intends to provide an overview on subtype-specific features, prognostic factors and operative techniques in the surgical management of retroperitoneal soft tissue sarcomas.

MATERIAL AND METHODS

A review of the literature addressing surgical management of retroperitoneal soft tissue sarcomas was performed. Current evidence and recommendations were summarized.

RESULTS AND CONCLUSION

Macroscopically complete tumor resection represents the sole curative treatment option for both primary and recurrent retroperitoneal soft tissue sarcomas. To minimize the probability of tumor-infiltrated resection margins, compartmental resection has become a standard treatment for retroperitoneal soft tissue sarcomas. This approach includes resection of all organs and structures adjacent to the tumor. Multivisceral resection is often associated with this approach and it is acceptable in terms of morbidity and mortality if performed at a center with experience in retroperitoneal sarcoma surgery. Histologic subtype, tumor grading, and quality of initial surgical treatment are major prognostic factors for oncologic overall survival.

Surgical and oncologic outcomes following arterial resection and reconstruction for advanced solid tumors

BACKGROUND AND OBJECTIVES

Although arterial involvement for advanced tumors is rare, vascular resection may be indicated to achieve complete tumor resection. Given the potential morbidity of this approach, we sought to evaluate perioperative outcomes, vascular graft patency, and survival among patients undergoing tumor excision with en bloc arterial resection and reconstruction.

METHODS

From 2010 to 2020, we identified nine patients with tumors encasing or extensively abutting major arterial structures for whom en bloc arterial resection and reconstruction was performed.

RESULTS

Mean age was 53 ± 20 years, and 89% were females. Diagnoses were primary sarcomas (5), recurrent gynecologic carcinomas (3), and benign retroperitoneal fibrosis (1). Tumors involved the infrarenal aorta (2), iliac arteries (6), and superficial femoral artery (1). Three patients (33%) had severe perioperative morbidity (Grade III + ) with no mortality. At a median follow-up of 23 months, eight patients (89%) had primary graft patency, and five patients (56%) had no evidence of disease.

CONCLUSIONS

Arterial resection and reconstruction as part of the multimodality treatment of regionally advanced tumors is associated with acceptable short- and long-term outcomes, including excellent graft patency. In appropriately selected patients, involvement of major arterial structures should not be viewed as a contraindication to attempted curative surgery.

[French ccAFU guidelines - update 2020-2022: retroperitoneal sarcoma]

OBJECTIVE

- To update French urological guidelines on retroperitoneal sarcoma.

MATERIALS AND METHODS

- Comprehensive Medline search between 2018 and 2020 upon diagnosis, treatment and follow-up of retroperitoneal sarcoma. Level of evidence was evaluated.

RESULTS

- Chest, abdomen and pelvis CT is mandatory to evaluate any suspected retroperitoneal sarcoma. MRI sometimes helps surgical planning. Before histological confirmation through biopsy, the patient must be registered in the French sarcoma pathology reference network. The biopsy standard should be an extraperitoneal coaxial percutaneous sampling before any retroperitoneal mass therapeutic decision. Surgery is retroperitoneal sarcoma cornerstone. The main objective is grossly negative margins and can be technically challenging. Multimodal treatment risks and benefits must be discussed in multidisciplinary teams. The relapse rate is related to tumor grade and surgical margins. Reported Negative margins rate thus encourage surgery in high-volume centers.

CONCLUSION

- Retroperitoneal sarcoma prognosis is poor and closely related to the quality of initial management. Centralization through dedicated sarcoma pathology network in a high-volume center is mandatory.

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.

Paratesticular liposarcoma: Two case reports

BACKGROUND

Paratesticular liposarcoma accounts for approximately 7% of scrotal tumors. They are rare lesions of the reproductive system with approximately 90% of the lesions originating from the spermatic cord. Surgery, with the goal of complete resection, is the mainstay for treatment of this disease. However, treatment consisting of extended resection to decrease local recurrence remains controversial.

CASE SUMMARY

We report the cases of two patients with paratesticular liposarcomas who were treated with radical testicular tumor resection without adjuvant therapy. Follow-up investigations at 9 mo showed no sign of recurrence.

CONCLUSION

Surgery is the first-line treatment, regardless of whether it is a recurrent or primary tumor. Extended resection carries a higher risk of complications and should not be performed routinely. Preoperative radiotherapy can reduce the local recurrence rate without affecting the overall survival.

Radical excision for retroperitoneal soft tissue sarcoma: A national propensity-matched outcomes analysis

BACKGROUND

Given the rarity of retroperitoneal soft tissue sarcoma, few studies have assessed if radical excision of retroperitoneal soft tissue sarcoma with adjacent organs improves survival outcomes. This propensity score-matched study aimed to evaluate the impact of radical excision versus resection of tumor alone.

METHODS

The National Cancer Database 2004 to 2015 was used to assess short- and long-term outcomes of resection of tumor alone versus radical excision (tumor plus ≥1 adjacent organs) via 1:1 propensity-matched analyses. Subgroup analyses included low-grade, high-grade, liposarcoma, leiomyosarcoma, adjacent organ involvement alone, localized tumors alone, and high-volume hospitals (≥10 resections/y). Multivariable logistic regression models identified factors associated with radical excision.

RESULTS

Comparison of propensity-matched groups (N = 1,139/group) revealed no significant differences in 30-day mortality, 90-day mortality, or overall survival (for all, P > .580). For all subgroup analyses comparing resection of tumor alone with radical excision, including localized tumors without organ invasion (N = 208/group), there were no identified differences in short- or long-term survival. Although it yielded lower R2 resection rates (P = .007), radical excision was associated with greater mean length of stay (P < .001).

CONCLUSION

Radical excision was not associated with improved retroperitoneal soft tissue sarcoma survival irrespective of grade, histology, hospital volume, or adjacent organ involvement. Resection of ostensibly involved adjacent viscera may increase morbidity without survival benefit. These results inform ongoing discussion regarding histology-tailored, situation-specific extent of retroperitoneal soft tissue sarcoma resections.

Outcome of patients with primary retroperitoneal solitary fibrous sarcoma

BACKGROUND

To describe the clinicopathological features of primary retroperitoneal solitary fibrous tumor (RSFT) and define the prognostic factors.

METHODS

The comprehensive data of 35 primary RSFT patients who got curative surgery at a tertiary cancer center from April 2004 to October 2018 were retrospectively analyzed.

RESULTS

Male patients outnumbered female patients (19 vs. 16), with the age ranging from 19 to 73 years (median, 51 years). 7 (20%) patients had tumors located in special parts, including three in kidney, one in renal pelvis, one in bladder, one in prostate, and one in mesentery. Tumor sizes ranged from 2.5 to 25 cm (median, 9 cm). Microscopic negative margin was reached in 33 (94.3%) cases. 13 (37.1%) were classified as atypical/malignant, while 22 (62.9%) were benign. Concomitant organ excision was performed on 11 (31.4%) patients, with kidney (n = 5) being the most frequent organ. Multifocality was only found in 4 (11.4%) cases. The majority of the patients (31, 88.6%) did not get adjuvant treatment. The median follow-up time was 46 months (range 4-153 months). The 5-year DSS rate and DFS rate were 100% and 63.6%, respectively. In univariate analysis, tumor size ≥ 10 cm (P = 0.002) and atypical/malignant pathology (P = 0.024) were associated with decreased DFS. Multivariate analysis revealed that tumor size was the only independent prognostic factor for DFS (HR 6.03, 95% CI 1.18-30.77, P = 0.031).

CONCLUSION

RSFT is uncommon, slow-growing, and recrudescent tumors. Large tumor size and malignant pathology are associated with decreased DFS. Tumor size ≥ 10 cm independently predicts shortened DFS.

Atypical Lipomatous Tumors: Does Our Inconsistent Terminology Have Patient Repercussions? Results of a Meta-Analysis

OBJECTIVES

Misnaming low-grade lipomatous tumors poses a clinical and medicolegal challenge, potentially subjecting patients to expensive and unnecessary surgeries. The terms atypical lipomatous tumor (ALT) and "well-differentiated" liposarcoma (WDL) have been used interchangeably in pathology reports, scholarly works and consensus recommendations, creating vagaries between low-virulence extremity tumors and retroperitoneal disease with metastatic potential.

METHODS

A systematic review was performed on all studies that reported on the local recurrence rate and metastasis of ALTs and WDLs in living human subjects. Local recurrence and metastases were compared using Fisher's Exact Test.

RESULTS

In total, 20 studies evaluated ALTs (n=936), whereas 13 studied WDLs (n=626). Mean follow-up was 6.6±2.0 years (median, 7.0 y). No metastatic disease was observed among ALTs, whereas 15 patients with WDLs (2.7%, P<0.0001) had metastases. The local recurrence rate of ALTs was significantly lower than WDLs after both marginal (15.1%, 141/936 vs. 46.0%, 288/626, P<0.0001) and wide excisions (3.3%, 2/59 in ALT vs. 17.4%, 19/109, P=0.007).

CONCLUSIONS

ALT should be reserved for extremity lesions meeting appropriate histopathologic criteria that represent nonmetastatic disease, reducing over-diagnosis, over-treatment, and patient risk.

Clinical characteristics and surgical outcomes of retroperitoneal tumors: a comprehensive data collection from multiple departments

BACKGROUND

There are only a limited number of comprehensive reports for retroperitoneal tumors (RPTs). The aim of this study was to perform an interdepartmental data collection for RPTs and to comprehensively clarify the clinical characteristics of this rare disease.

METHODS

All patients who were diagnosed with RPT from January 2005 to July 2018 in a single institution were included. The analyzed factors included demographics, clinical features, treatment methods, pathological diagnosis, and prognosis.

RESULTS

A total of 422 patients (215 males and 207 females) with primary RPTs were identified. Biopsy for RPT was performed in 180 patients (43%). Among the 422 patients, 239 (57%) underwent surgery. The most common tissue origin was mesodermal (n = 99, 41%), followed by neurogenic (n = 54, 23%), extragonadal (n = 27, 11%), and metastatic tumors (n = 13, 5%). Among the 99 resected mesodermal tumors, the most common pathological subtypes were liposarcoma (n = 55, 56%) and leiomyosarcoma (n = 16, 16%). The long-term outcomes after surgery were analyzed in patients with intermediate and malignant sarcomas (including liposarcoma, leiomyosarcoma, and others combined, n = 71). The 3- and 5-year disease-free survival rates in the intermediate tumors were 68.2% and 54.2%, respectively, whereas those in the malignant tumors were 48.6% and 28.9%, respectively. The 3- and 5-year overall survival rates in the intermediate tumors were 100% and 94.1%, respectively, whereas those in the malignant tumors were 78.4% and 72.8%, respectively (p = 0.009).

CONCLUSIONS

The clinical manifestations of RPTs were extremely variable. Recurrence after repeating resection is commonly observed in patients with malignant retroperitoneal sarcoma.

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.

Retroperitoneal dedifferentiated liposarcoma: Analysis of 61 cases from a large institution

Background: To describe the clinical features of retroperitoneal dedifferentiated liposarcoma (RP DDLS) and further evaluate the prognostic factors.

Methods: The clinicopathological variables and treatment strategies of 61 RP DDLS patients who underwent surgical resections at a single institution between September 2005 and September 2016 were reviewed. Kaplan-Meier and Cox regression methods were conducted for survival analyses.

Results: The average patients' age was 52 years (range, 27-81), and there was almost no gender predilection (30 males vs. 31 females). 51 (83.6%) patients got gross tumor resections (R0/R1 resection), and the median tumor size was 19 cm (range, 4.3-50 cm). 39(63.9%) patients were with intermediate-grade sarcoma and 22(36.1%) were with high-grade sarcoma. The median intraoperative blood loss was 400 ml (range, 50-2700ml). 19 (31.1%) patients presented multifocal diseases. Tumors were removed intactly in 42 (68.9%) patients. In order to obtain gross tumor resections, 33 (54.1%) of the patients underwent excisions of at least one adjacent organ, of which kidney (n=21, 63.6%) was the most common one. 6 (9.8%) patients developed distant metastases during follow-up. The overall 5-year progression-free survival (PFS) rate was 3.7%, with the median PFS of 19 months. The 5-year overall survival (OS) rate was 43.5%, with the median OS of 58 months. Updating to November 2017, 30 (49.2%) patients remained alive. The median follow-up time was 49 months. Multivariate analysis using Cox proportional hazards model revealed that tumor grade, blood loss, resection extent, and tumor integrity were independently associated with OS (p=0.032, p=0.018, p=0.020, p=0.005, respectively). Tumor grade, tumor integrity and multifocality were significant predictors for PFS (p=0.013, p=0.080, p=0.009, p=0.028, respectively).

Conclusion: Intermediate-grade histology, intraoperative blood loss < 400 ml, complete tumor resection, and tumor integrity were independently associated with better OS. Intermediate-grade histology, tumor integrity and unifocal disease independently predicted favorable PFS.