UNASSIGNED: Intraabdominal and retroperitoneal leiomyosarcomas are rare cancers, which cause significant morbidity and mortality. Symptoms, treatment and follow up differs from other cancers, and proper diagnosis and treatment of intraabdominal and retroperitoneal leiomyosarcomas is of utmost importance. We performed a systematic review to collect and summarize available evidence for diagnosis and treatment for these tumours.
UNASSIGNED: We performed a systematic literature search of Pubmed from the earliest entry possible, until January 2021. Our search phrase was (((((colon) OR (rectum)) OR (intestine)) OR (abdomen)) OR (retroperitoneum)) AND (leiomyosarcoma). All hits were evaluated by two of the authors.
UNASSIGNED: Our predefined search identified 1983 hits, we selected 218 hits and retrieved full-text copies of these. 144 studies were included in the review.
UNASSIGNED: This review summarizes the current knowledge and evidence on non-uterine abdominal and retroperitoneal leiomyosarcomas. The review has revealed a lack of high-quality evidence, and randomized clinical trials. There is a great need for more substantial and high-quality research in the area of leiomyosarcomas of the abdomen and retroperitoneum.
UNASSIGNED: PROSPERO, identifier, CRD42023480527.

Preoperative biopsy for retroperitoneal sarcoma (RPS) enables appropriate multidisciplinary treatment planning. A systematic review of literature from 1990 to June 2022 was conducted using the population, intervention, comparison and outcome model to evaluate the local recurrence and overall survival of preoperative biopsy compared to those that had not. Of 3192 studies screened, five retrospective cohort studies were identified. Three reported on biopsy needle tract seeding, with only one study reporting biopsy site recurrence of 2 %. Two found no significant difference in local recurrence and one found higher 5-year local recurrence rates in those who had not been biopsied. Three studies reported overall survival, including one with propensity matching, did not show a difference in overall survival. In conclusion, preoperative core needle biopsy of RPS is not associated with increased local recurrence or adverse survival outcomes.

Retroperitoneal sarcoma (RPS) is a rare tumor classified into many histological types. It is also often detected only after it has grown to a considerable size and requires extensive resection of the surrounding organs, making it difficult to offer optimal patient-tailored management. Evidence supporting specific treatment modalities for RPS is insufficient, owing to its rarity. The Japanese clinical practice guidelines for RPS were published in December 2021, with the aim of accumulating existing evidence and indicating the optimal practice for RPS. These guidelines provide important clinical questions (CQs) concerning the diagnosis and treatment of RPS. This review, with a particular focus on primary RPS, attempts to introduce clinical problems in the diagnosis and treatment of RPS and to assess those problems along with the CQs in the guidelines. According to these guidelines, although chemotherapy and radiotherapy are expected to have therapeutic effects, the level of evidence to support these treatments is not very high at present. Accordingly, complete resection of the tumor is the first and only option for managing primary RPS. However, as with other tumors, the demand for multidisciplinary treatment for RPS is increasing. These guidelines will undoubtedly represent a milestone in clinical practice in relation to RPS in the future, and further evidence is expected to be accumulated based on the CQs that have been proposed.

BACKGROUND: In primary localised resectable retroperitoneal sarcoma (RPS), loco-regional and distant relapse occur frequently despite optimal surgical management. The role of chemotherapy in improving outcomes is unclear.
METHODS: A systematic review was conducted, using the population, intervention, comparison outcome (PICO) model, to evaluate whether neoadjuvant or adjuvant chemotherapy improve outcomes in adults with primary localised resectable RPS. Medline, Embase and Cochrane Central were queried for publications from 1946 to June 2022 that evaluated recurrence free survival, overall survival, and post operative complications. Each study was screened by two independent reviewers for suitability. A qualitative synthesis of the results was performed.
RESULTS: Twenty three studies were identified; one meta-analysis of retrospective studies and 22 retrospective studies including three with propensity matched cohorts. Most studies did not analyse outcomes by histology, detail treatment regimens, provide baseline characteristics or selection criteria for those receiving chemotherapy. Evidence of selection bias was illustrated in several studies. Newcastle-Ottawa quality of retrospective cohort studies was good for 12 studies and poor for 10 studies. All studies were assessed as Level III-2 evidence by the Australian NHMRC hierarchy. Overall, the addition of neoadjuvant or adjuvant chemotherapy to surgery was not associated with improvement in local recurrence, metastasis free survival, disease free survival or overall survival in primary localised resectable RPS. There is some evidence of an association of chemotherapy with worse overall survival. One single centre study showed that neoadjuvant chemotherapy was not associated with increased post operative complications compared to surgery alone in primary localised resectable RPS.
CONCLUSIONS: There is currently no evidence that demonstrates the addition of chemotherapy to surgery improves outcomes in adult patients with primary localised resectable RPS. Available evidence is limited by its retrospective nature and high likelihood of selection bias with chemotherapy generally administered to patients at higher risk of recurrence and many patients not receiving care in high volume sarcoma centres. Randomised trials are required to conclusively determine the role of chemotherapy in primary localised resectable RPS.

OBJECTIVE: 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.

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.

Soft tissue sarcomas (STS) are an uncommon and biologically heterogeneous group of tumors arising from mesenchymal cells. The incidence is estimated at five cases per 100,000 people per year. Retroperitoneal sarcomas (RPS) account for 10-15% of all STS, and their management depends on their anatomical characteristics and histotype. Due to their very low incidence, it is recommended that RPS be treated in reference centers and evaluated by an experienced multidisciplinary team (MDT). In Spain, the Spanish Group for Research in Sarcomas (GEIS) brings together experts from various specialties to promote research on sarcomas and improve treatment results. This paper summarizes the GEIS recommendations for the diagnosis, treatment, and follow-up of patients with RPS.

Most soft tissue sarcomas afflict the extremities; however, the retro peritoneum can also be affected rarely. Retroperitoneal sarcomas are relatively asymptomatic. Although tumor-induced hypoglycemia is rare in tumors other than insulinomas, extrapancreatic tumors are a subset that displays this phenomenon. The occurrence of hypo-insulinemic hypoglycemia with low GH and IGF-1 should prompt consideration of the secretion of a hypoglycemic substance impeding the secretion of insulin and GH, such as IGF-2 or one of its related substances. The present case report is of a 38-year-old male with retroperitoneal round cell sarcoma with liver metastasis with severe symptomatic hypoglycemia who was managed with multipronged symptomatic therapy and oncological management after which he had shown significant improvement in hypoglycemic episodes and symptom profile. A literature review revealed our case report to be the first reported case of a young male (preponderance in the older population) with hypoglycemia associated with retroperitoneal sarcoma which presented with liver metastasis and the only one treated with Gemcitabine /Docetaxel. The presence of these features might point toward a poorer prognosis in a disease with an already dismal course. All these points towards the need for further research regarding intensified oncological treatment after evidence-based prognostication of high-risk groups and modalities for the management of symptomatic hypoglycemia such as Somatostatin analogs and glucagon which aid in symptom control.

To describe the introduction of extracorporeal corporeal oxygenation (ECMO) to facilitate the surgical resection of large retroperitoneal sarcomas involving major vessels and to report preliminary outcomes.
A case series.
At a tertiary university hospital and state sarcoma center.
Patients undergoing retroperitoneal sarcoma resection requiring inferior vena cava (IVC) reconstruction between June 2018 and March 2022.
ECMO for retroperitoneal tumor resection requiring IVC reconstruction.
A total of 20 patients underwent ECMO-assisted retroperitoneal sarcoma resection and IVC reconstruction. The median age was 60.5 years (IQR 48-69); 15 women and 5 men. The median procedure and ECMO durations were 10.8 hours (IQR 8.5-12.4 hours) and 2.2 hours (IQR 62-218 minutes), respectively. The median intensive care unit and hospital lengths of stay were 4 days (IQR 3-5 days) and 21 days (IQR 14-31 days), respectively. All 20 patients received packed cell transfusions (median 8 per patient [IQR 4-14]); 11 patients required fresh frozen plasma, 6 required platelets, and 11 required fibrinogen supplementation. One patient required recombinant activated factor VII. Sixteen patients experienced acute kidney injury, with 12 patients progressing to chronic kidney disease. Three patients were required to return to the operating room within 7 days, with no returns within the first 24 hours. There was no in-hospital or 30-day mortality. Survival at 3 years was 84%.
ECMO for resecting large retroperitoneal tumor resection was introduced successfully and facilitated satisfactory outcomes for many patients who might otherwise have been considered too high risk.

UNASSIGNED: Retroperitoneal liposarcoma (RPLS) is a rare malignancy that is notorious for recurrence. Surgical resection with clean margin is the current treatment of choice. However, owing to the large retroperitoneal space, RPLSs often grow to significant sizes before being diagnosed. Neoadjuvant and adjuvant therapies have potentials to improve long term treatment outcome.
UNASSIGNED: A 55-year-old Han Chinese male presented to the general surgery department with a one-year history of abdominal fullness and a one-week history of palpable right inguinal mass. At first, he was diagnosed with incarcerated inguinal hernia. However, abdominal computer tomography (CT) and biopsy confirmed his final diagnosis to be retroperitoneal well-differentiated liposarcoma, cT2bN0M0, stage IIb. The tumor, which measured 44.5cm in maximum diameter, was too large for primary surgical resection. Neoadjuvant radiotherapy with 70 Gy in 35 fractions was delivered to the tumor, which shrunk the target volume from 6300 cc to 4800 cc, as observed in the middle of the radiotherapy course. The right testicular mass also received 70Gy/35Fx. Conversion surgery was performed after radiotherapy. Unfortunately, due to residual tumor, adjuvant chemotherapy consisting of AIM (ifosfamide, Mesna, and doxorubicin) and MAID (Mesna, doxorubincin, ifosfamide, and dacarbazine) regimens were administered sequentially. Afterward, debulking surgery was conducted, plus another 18 cycles of ifosfamide monotherapy when residual tumor was still seen on CT. Since the completion of ifosfamide chemotherapy, the patient has been cancer free with no evidence of tumor recurrence for more than 26 months.
UNASSIGNED: Despite conflicting evidence in the literature, our case supports the use of high dose neoadjuvant radiotherapy and adjuvant chemotherapy in treating large, unresectable RPLSs. It also highlights the importance of using individualized, multidisciplinary approach in achieving cure for large, unresectable rare tumors.