Special clinical scenarios in RPS: Involvement of great vessels and pancreas and penetration across natural foramina

The primary treatment for retroperitoneal sarcomas is surgery. This requires a carefully planned, typically multivisceral, resection. A few complex scenarios that may arise include vascular involvement, pancreatic involvement, or herniation of the tumor into another compartment outside of the retroperitoneum. These scenarios must be anticipated before surgery to optimize preoperative preparation, minimize postoperative morbidity and mortality, and improve oncologic outcomes. Our aim is to highlight these clinically challenging anatomic presentations that can be encountered in patients with retroperitoneal sarcomas.

Pelvic soft tissue sarcomas

Pelvic soft tissue sarcomas (PSTS) are a rare, heterogeneous group of tumors. They have been usually analyzed with retroperitoneal sarcomas (RPS), but actually have key differences. Due to their unique anatomic location, symptomatic presentation of PSTS may be more common than RPS. Adequate imaging approach is paramount for guiding differential diagnosis, while preoperative biopsy is mandatory, especially when preoperative treatment may be considered as initial approach. The most frequent histologic subtype is leiomyosarcoma, which is different as expected in the retroperitoneum where liposarcoma is the commonest histology. Also solitary fibrous tumor is commonly diagnosed in the pelvis. Surgical approach for PSTS differs from that for RPS mainly due to anatomic relations. Similarly, in the lack of definite evidence from specific trials about neoadjuvant and adjuvant treatments, the anatomic constraints to obtain wide margins in the pelvis as well as the expected functional outcome in case of organ resections should be factored into decision for individualized treatment offer. Vascular and genitourinary involvement are frequent, as well as herniation through pelvic foramina. For these reasons a multidisciplinary surgical team should always be considered. Early referral of these patients to high-volume centers is critical and may impact on survival, given that optimal initial resection is a major predictor of curative treatment. International consensus on PSTS treatment is advocated, similarly to the recent efforts realized for RPS.

A Planned Multidisciplinary Surgical Approach to Treat Primary Pelvic Malignancies

The pelvic anatomy poses great challenges to orthopedic surgeons. Sarcomas are often large in size and typically enclosed in the narrow confines of the pelvis with the close proximity of vital structures. The aim of this study is to report a systematic planned multidisciplinary surgical approach to treat pelvic sarcomas. Seventeen patients affected by bone and soft tissue sarcomas of the pelvis, treated using a planned multidisciplinary surgical approach, combining the expertise of orthopedic oncology and other surgeons (colleagues from urology, vascular surgery, abdominal surgery, gynecology and plastic surgery), were included. Seven patients were treated with hindquarter amputation; 10 patients underwent excision of the tumor. Reconstruction of bone defects was conducted in six patients with a custom-made 3D-printed pelvic prosthesis. Thirteen patients experienced at least one complication. Well-organized multidisciplinary collaborations between each subspecialty are the cornerstone for the management of patients affected by pelvic sarcomas, which should be conducted in specialized centers. A multidisciplinary surgical approach is of paramount importance in order to obtain the best successful surgical results and adequate margins for achieving acceptable outcomes.

Oncologic outcomes of surgically managed primary pelvic soft tissue sarcoma; tumour biology or surgical constraints of the true pelvis?

BACKGROUND

Pelvic soft tissue sarcomas are rare. Potentially curative resection remains challenging due to anatomical constraints of true pelvis and tumour spread through various anatomical hiatus. We sought to review the oncological outcomes of surgically managed cases at our centre and determine whether outcomes differ for patients with localised (limited to pelvis) versus extensive disease (with extra-pelvic extension).

METHODS

Sixty-seven patients who underwent surgical resection with curative intent at the centre for primary, non-metastatic, WHO intermediate to high-grade soft tissue sarcoma of the true pelvis from January 2012 through January 2020 were analysed. Establishment of the extent of disease was made by review of pre-treatment imaging and surgical notes. Oncologic endpoints examined were resection margin, recurrence rate, disease-free and overall survival.

RESULTS

Rates of complete oncological resection and disease control were similar for tumours with localised or extensive disease. On logistic regression analysis, tumour grade, and a negative resection margin (R0) correlated with the risk of recurrence (p=<0.05). On further multinomial analysis, R0 resection was associated with improved local control, but not metastatic relapse (p = 0.003). 5-year local recurrence-free and distant metastasis-free survival were 61.3% and 67.1%, respectively. Five and 10-year overall survival were 64% and 36%, respectively. Age >50 years and high tumour grade were associated with a worse outcome (p < 0.05).

CONCLUSIONS

When potentially curative surgery is performed for pelvic sarcoma, disease-extent does not influence oncologic outcomes. While a complete oncologic resection determines the risk of local recurrence, tumour grade and metastatic relapse remain primary prognostic determinants for overall survival.

Surgical Principles of Primary Retroperitoneal Sarcoma in the Era of Personalized Treatment: A Review of the Frontline Extended Surgery

Simple Summary

Surgery is the only curative treatment for localized disease in retroperitoneal sarcoma (RPS). Frontline extended surgery, or compartmental surgery, is a recent surgical strategy consisting of resecting the tumor together with adjacent organs, with the aim of minimizing marginality. This review provides a practical step by step description of this standardized procedure, tailored to histologic behavior, tumor localization, and patient condition.

Abstract

Surgery is the key treatment in retroperitoneal sarcoma (RPS), as completeness of resection is the most important prognostic factor related to treatment. Compartmental surgery/frontline extended approach is based on soft-tissue sarcoma surgical principles, and involves resecting adjacent viscera to achieve a wide negative margin. This extended approach is associated with improved local control and survival. This surgery must be tailored to tumor histology, tumor localization, and patient performance status. We herein present a review of compartmental surgery principles, covering the oncological and technical basis, and describing the tailored approach to each tumor subtype and localization in the retroperitoneum.

Treatment for local control of retroperitoneal and pelvis sarcomas: A review of the literature

Retroperitoneal and pelvis sarcomas are uncommon tumors for which complete surgical resection is the mainstay of treatment. However, achieving complete gross resection with microscopically negative margins is challenging, and local recurrence rates can be high. Patients often succumb to uncontrolled local disease. Radiation therapy offers a potential means for sterilizing microscopic residual disease, although its use continues to be controversial. Chemotherapy alone or in combination with radiation continues to be investigated as an adjunct to surgery, along with immunotherapy and targeted therapies. In this review, we discuss the current management of retroperitoneal and pelvis sarcomas, focusing on studies of surgery and radiation therapy to maximize local control.

Surgical navigation for challenging recurrent or pretreated intra-abdominal and pelvic soft tissue sarcomas

BACKGROUND

This study assessed whether electromagnetic navigation can be of added value during resection of recurrent or post-therapy intra-abdominal/pelvic soft tissue sarcomas (STS) in challenging locations.

MATERIALS AND METHODS

Patients were included in a prospective navigation study. A pre-operatively 3D roadmap was made and tracked using electromagnetic reference markers. During the operation, an electromagnetic pointer was used for the localization of the tumor/critical anatomical structures. The primary endpoint was feasibility, secondary outcomes were safety and usability.

RESULTS

Nine patients with a total of 12 tumors were included, 7 patients with locally recurrent sarcoma. Three patients received neoadjuvant radiotherapy and three other patients received neoadjuvant systemic treatment. The median tumor size was 4.6 cm (2.4-10.4). The majority of distances from tumor to critical anatomical structures was <0.5 cm. The tumors were localized using the navigation system without technical or safety issues. Despite the challenging nature of these resections, 89% were R0 resections, with a median blood loss of 100 ml (20-1050) and one incident of vascular damage. Based on the survey, surgeons stated navigation resulted in shorter surgery time and made the resections easier.

CONCLUSION

Electromagnetic navigation facilitates resections of challenging lower intra-abdominal/pelvic STS and might be of added value.

Resection of a giant retroperitoneal lipoma herniating through the inguinal canal

Retroperitoneal lipomas are extremely rare with few cases reported so far in the literature. They can reach different sizes and present with a variety of symptoms. The differential diagnosis is mainly with well-differentiated liposarcoma (WDLPS). We present a 34-year-old woman with a retroperitoneal lipoma herniating through the inguinal canal into the proximal thigh. The patient underwent complete oncological resection using a Karakousis's abdominoinguinal incision. Retroperitoneal lipomas are a very rare condition and sometimes require resections technically challenging. MDM2 amplification is critical for its differential diagnosis with WDLPS.

Update in pelvic and retroperitoneal sarcoma management: The role of compartment surgery

Surgery for retroperitoneal sarcomas should be "en bloc" compartmental, which involves resection of unaffected organs. Its upfront use is key, providing a high percentage of resections with negative margins, resulting in a better local control and increased survival in many patients. Preservation of organs should be done in an individualized manner, especially in the pelvic location, and adapted to the histological aggressiveness of the tumor. Preoperative biopsy is able to establish the diagnosis of sarcoma subtype and consequently an adequate perioperative strategy. These patients should be managed by expert surgeons at referral centers with multidisciplinary units and oncology committees. The use of chemotherapy and radiotherapy is not yet well defined, so it is only recommended at referral centers with clinical trials. Currently, this is the only option to offer the best morbidity and mortality rates, as well as possible improvements in the survival of these patients.