Surgical management of retroperitoneal and pelvic sarcomas

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.

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.

Study of the efficacy of 3D-printed prosthetic reconstruction after pelvic tumour resection

The purpose of this study is to explore the effect of using 3D printed pelvic prosthesis to reconstruct bone defect after pelvic tumor resection. From June 2018 to October 2021, a total of 10 patients with pelvic tumors underwent pelvic tumor resection and 3D printed customized hemipelvic prosthesis reconstruction in our hospital. Enneking pelvic surgery subdivision method was used to determine the degree of tumor invasion and the site of prosthesis reconstruction. 2 cases in Zone I, 2 cases in Zone II, 3 cases in Zone I + II, 2 cases in Zone II + III and 1 case in Zone I + II + III. Patients had preoperative VAS scores of 6.5 ± 1.3, postoperative VAS scores of 2.2 ± 0.9, preoperative MSTS-93 scores of 9.4 ± 5.3 and postoperative 19.4 ± 5.9(p < 0.05), all patients had improvement in pain after surgery; Postoperative complications included joint dislocation in 2 cases, myasthenia caused by Guillain-Barre syndrome in 1 case, delayed wound healing in 3 cases and wound infection in 2 cases. Postoperative wound-related complications and dislocations were associated with the extent of the tumor. Patients with tumor invasion of the iliopsoas and gluteus medius muscles had higher complication rates and worse postoperative MSTS scores (p < 0.05). The patients were followed up for 8 ∼ 28 months. During the follow-up period, 1 case recurred, 4 cases metastasized and 1 case died. All pelvic CTs reviewed 3-6 months after surgery showed good alignment between the 3D printed prosthesis and the bone contact, and tomography showed the growth of trabecular structures into the bone. Overall pain scores decreased and functional scores improved in patients after 3D printed prosthesis replacement for pelvic tumor resection. Long-term bone ingrowth could be seen on the prosthesis-bone contact surface with good stability.

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.

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.

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

BACKGROUND

A novel Palladium-103 low-dose rate (LDR) brachytherapy device was developed to provide dose-escalation to the tumor bed after resection while shielding adjacent tissues. This multicenter report describes the initial experience with this device in patients with retroperitoneal sarcoma (RPS).

MATERIALS AND METHODS

Patients with recurrent RPS, prior radiotherapy, and/or concern for positive margins were considered. An LDR brachytherapy dose of 20-60 Gy was administered, corresponding to biologically effective dose values of 15-53 Gy and equivalent dose values of 12-43 Gy.

RESULTS

Six patients underwent implantation at four institutions. Of these, five had recurrent disease in the retroperitoneum or pelvic sidewall, one had untreated locally advanced leiomyosarcoma, two had prior external beam radiation therapy at the time of initial diagnosis, and four received neoadjuvant external beam radiation therapy plus brachytherapy. The device was easily implanted and conformed to the treatment area. Median follow-up was 16 mo; radiation was delivered to the at-risk margin with minimal irradiation of adjacent structures. No local recurrences at the site of implantation, device migration, or radiation-related toxicities were observed.

CONCLUSIONS

The novel LDR directional brachytherapy device successfully delivered a targeted dose escalation to treat RPS high-risk margins. Lack of radiation-related toxicity demonstrates its safety.

Clinical study of 3D printed personalized prosthesis in the treatment of bone defect after pelvic tumor resection

Background

/Objective: In recent years, prostheses have been widely used for limb reconstruction after pelvic tumour resection. However, prostheses are associated with problems leading to tumour recurrence, poor implant matching, defects after tumour resection, and easy implant looseness or failure. To achieve a precise preoperative design, complete tumour resection, and better anatomical structure matching and prosthesis stability, this study used three-dimensionally (3D)-printed osteotomy guides and personalised prostheses for reconstruction after pelvic tumour resection. This study aimed to explore the early clinical efficacy of 3D printed personalised prostheses for the reconstruction of bone defects after pelvic tumour resection.

Methods

A total of 20 patients (12 males, 8 females) with pelvic tumours surgically treated at our hospital between October 2014 and October 2019 were selected. There were 10 cases each of giant cell bone tumours and osteochondrosarcomas. According to Enneking zoning, there were 11 and 9 cases with tumours located in zones I and II, respectively. All cases were equally divided into conventional and 3D printing groups. For repair and reconstruction, a nail rod system or a steel plate was used in the conventional group while individualised 3D-printed prostheses were used in the 3D printing group. The surgical incision, duration of surgery, intraoperative blood loss, and the negative rate of resection margins in postoperative tumour specimens were examined. The follow-up focused on tumour recurrence, complications, and the Musculoskeletal Tumor Society (MSTS) score.

Results

All cases were followed-up for 6-24 months. The average incision length, duration of surgery, amount of intraoperative blood loss, and MSTS score of the 3D printing group were 10.0 ± 3.1 cm, 115.2 ± 25.3 min, 213.2 ± 104.6 mL, 23.8 ± 1.3, respectively, and those of the conventional group were 19.8 ± 8.4 cm, 156.8 ± 61.4 min, 361.4 ± 164.2 mL, and 18.3 ± 1.4, respectively. Histological tumour specimen examination showed nine and three cases with negative resection margins in the 3D printing group and the conventional group, respectively. The abovementioned indicators were significantly different between both groups (P < 0.05).

Conclusion

Applying 3D printed surgical guides and personalised prostheses for pelvic tumour resection, repair, and reconstruction, as well as preoperative planning and design, enables more accurate tumour resections and better prosthesis-patient matchings, possibly reducing surgical trauma, shortening the duration of surgery, and promoting the functional recovery of patients postoperatively.

The Translation Potential of this Article

Contrary to existing studies on 3D printed personalised prostheses, this study reports the clinical efficacy of the aforementioned technology in treating bone defects in a series of patients who underwent pelvic tumour resection. Moreover, it presents a comprehensive comparison of this technology with conventional procedures, thus strengthening its importance in treatment regimens for reconstructing bone defects.

Different quality of treatment in retroperitoneal sarcomas (RPS) according to hospital-case volume and surgeon-case volume: a retrospective regional analysis in Italy

Background

Retroperitoneal sarcomas (RPS) should be surgically managed in specialized sarcoma centers. However, it is not clearly demonstrated if clinical outcome is more influenced by Center Case Volume (CCV) or by Surgeon Case Volume (SCV). The aim of this study is to retrospectively explore the relationship between CCV and SCV and the quality of surgery in a wide region of Northern Italy.

Methods

We retrospectively collected data about patients M0 surgically treated for RPSs in 22 different hospitals from 2006 to 2011, dividing them in two hospital groups according to sarcoma clinical activity volume (HCV, high case volume or LCV, low case volume hospitals). The HCV group (> 100 sarcomas observed per year) included a Comprehensive Cancer Center (HVCCC) with a high sarcoma SCV (> 20 cases/year), and a Tertiary Academic Hospital (HVTCA) with multiple surgeon teams and a low sarcoma SCV (≤ 5 cases/year for each involved surgeon). All other hospitals were included in the LCV group (< 100 sarcomas observed per year).

Results

Data regarding 138 patients were collected. Patients coming from LCV hospitals (66) were excluded from the analysis as prognostic data were frequently not available. Among the 72 remaining cases of HCV hospitals 60% of cases had R0/R1 margins, with a more favorable distribution of R0/R1 versus R2 in HVCCC compared to HVTCA.

Conclusions

In HCV hospitals, sarcoma SCV may significantly influence RPS treatment quality. In low-volume centers surgical reports can often miss important prognostic issues and surgical quality is generally poor.

Effect of nephrectomy for retroperitoneal sarcoma on post-operative renal function

BACKGROUND AND OBJECTIVES

Surgical resection of retroperitoneal sarcomas (RPS) often involves removal of the ipsilateral kidney. We evaluated the long-term post-operative renal function in patients who underwent a nephrectomy as part of their en-bloc resection of RPS.

METHODS

Retrospective review of an institutional database identified RPS patients who underwent nephrectomy for curative intent from 1990 to 2014. The primary outcome measured was chronic kidney disease (CKD) calculated by the glomerular filtration rate (GFR).

RESULTS

Of the 47 patients in our study, 19 (40%), 18 (38%), and 10 (21%) patients had a preoperative CKD stage 1, 2, and 3, respectively. The GFR decreased by an average of 33.4 mL/min/1.73 m² with 66% of patients demonstrating mild progression of their renal impairment. Only three (6%) patients progressed to CKD stage 4 or 5, one of which required life-long dialysis.

CONCLUSION

Nephrectomy as part of an en-bloc resection is associated with a decrease in GFR that is not clinically significant. Fear of kidney failure should not prevent a surgeon from performing a nephrectomy in the treatment of RPS.

Demographics, management and treatment outcomes of benign and malignant retroperitoneal tumors in Japan

OBJECTIVES

To show the demographics, type of treatment and clinical outcomes of patients with retroperitoneal tumors in Japan.

METHODS

We carried out a retrospective analysis of patients with retroperitoneal tumors treated between 2000 and 2012 at 12 university hospitals in Japan. Histology was re-evaluated using the 2013 World Health Organization classification.

RESULTS

A total of 167 patients were included in the analysis. The number of diagnosed patients increased over the 12-year study period. Liposarcoma and schwannoma were the most common histological types among intermediate/malignant and benign tumors, respectively. The intermediate/malignant tumors were larger and were more frequently found in older people. Surgical resection was the primary treatment for 151 patients. The median survival duration for patients with malignant tumors was 91 months, and was significantly shorter than that for patients with benign and intermediate tumors (P < 0.01). R2 resection was associated with significantly shorter survival than R0/R1 resection for malignant tumors (P < 0.01), but not for intermediate. Grossly complete resection of the recurrent tumors improved survival.

CONCLUSION

The number of patients diagnosed with retroperitoneal tumors increased over time. R2 resection of primary tumors was found to be associated with poor prognosis in malignant tumors, but not in intermediate tumors. Complete surgical resection of recurrent tumors was associated with a better oncological outcome.

Delayed phlegmon with gallstone fragments masquerading as soft tissue sarcoma

Complications from lost gallstones after cholecystectomy are rare but varied from simple perihepatic abscess to empyema and expectoration of gallstones. Gallstone complications have been reported in nearly every organ system, although reports of malignant masquerade of retained gallstones are few. We present the case of an 87-year-old woman with a flank soft tissue tumor 4 years after laparoscopic cholecystectomy. The initial clinical, radiographic and biopsy findings were consistent with soft tissue sarcoma (STS), but careful review of her case in multidisciplinary conference raised the suspicion for retained gallstones rather than STS. The patient was treated with incisional biopsy/drainage of the mass, and gallstones were retrieved. The patient recovered completely without an extensive resectional procedure, emphasizing the importance of multidisciplinary sarcoma care to optimize outcomes for potential sarcoma patients.

Radiation-associated sarcoma after recurrent colorectal primary tumor: A complex surgical case

Radiation associated sarcoma is a significant consequence of cancer therapy. Incidence of radiation associated sarcoma correlates with overall radiotherapy exposure. Prognosis is generally poor with 5 year survival rates lower than that for spontaneously occurring sarcomas. Surgical management presents many challenges including having to work in irradiated tissue planes while trying to achieve negative margins. We present a patient with a rare radiation associated pelvic sarcoma whose course illustrates the complexity of this problem.