Pelvic Soft Tissue Sarcomas Research Articles

The Effect of Surgical Resection on Cancer-Specific Mortality in Pelvic Soft Tissue Sarcoma According to Histologic Subtype and Stage

Background/Objectives: The impact of surgical resection versus non-resection on cancer-specific mortality (CSM) in soft tissue pelvic sarcoma remains largely unclear, particularly when considering histologic subtypes such as liposarcoma, leiomyosarcoma, and sarcoma NOS. The objective of the present study was to first report data regarding the association between surgical resection status and CSM in soft tissue pelvic sarcoma. Methods: Using data from the Surveillance, Epidemiology, and End Results (SEER) database from 2000 to 2019, we identified 2491 patients diagnosed with pelvic soft tissue sarcoma. Cumulative incidence plots were used to illustrate CSM and other-cause mortality rates based on the histologic subtype and surgical resection status. Competing risk regression models were employed to assess whether surgical resection was an independent predictor of CSM in both non-metastatic and metastatic patients. Results: Among the 2491 patients with soft tissue pelvic sarcoma, liposarcoma was the most common subtype (41%), followed by leiomyosarcoma (39%) and sarcoma NOS (20%). Surgical resection rates were 92% for liposarcoma, 91% for leiomyosarcoma, and 58% for sarcoma NOS in non-metastatic patients, while for metastatic patients, the rates were 55%, 49%, and 23%, respectively. In non-metastatic patients who underwent surgical resection, five-year CSM rates by histologic subtype were 10% for liposarcoma, 32% for leiomyosarcoma, and 27% for sarcoma NOS. The multivariable competing risk regression analysis showed that surgical resection provided a protective effect across all histologic subtypes in non-metastatic patients (liposarcoma HR: 0.2, leiomyosarcoma HR: 0.5, sarcoma NOS HR: 0.4). In metastatic patients, surgical resection had a protective effect for those with leiomyosarcoma (HR: 0.6) but not for those with sarcoma NOS. An analysis for metastatic liposarcoma was not possible due to insufficient data. Conclusions: In non-metastatic soft tissue pelvic sarcoma, surgical resection may be linked to a reduction in CSM. However, in metastatic patients, this protective effect appears to be limited primarily to those with leiomyosarcoma.

Primary pelvic soft tissue sarcomas (PELVISARC): outcomes from the TransAtlantic Australasian Retroperitoneal Sarcoma Working Group (TARPSWG).

Primary pelvic soft tissue sarcomas (PELVISARC): outcomes from the TransAtlantic Australasian Retroperitoneal Sarcoma Working Group (TARPSWG).

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

BackgroundPelvic 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). MethodsSixty-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. ResultsRates 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). ConclusionsWhen 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.

Resection of Recurrent Pelvic Soft Tissue Sarcoma: Is the Risk Worth the Reward?

IntroductionSoft tissue sarcomas (STS) of the pelvis present a surgical and oncological challenge. We investigated the outcomes of patients undergoing resection of pelvic sarcomas. MethodsA retrospective analysis of all patients who underwent surgical resection for STS between 2014 and 2021 at a tertiary academic referral center (n = 172). Included all patients with primary or recurrent STS which originated or extended to the pelvic cavity (n = 29). ResultsThe cohort was divided into primary pelvic sarcomas (n = 18) and recurrent pelvic sarcomas (rPS, n = 11). Complete R0/R1 resection was achieved in 26 patients (89.6%). The postoperative complication rate was 48.3%. The rate of major complications was 27.5%. The median time of follow-up from surgery was 12.3 months (range, 0.6-60.3 months). Disease-free survival was superior in the primary pelvic sarcomas group compared to the rPS group (P = 0.002). However, there was no significant difference in overall survival, (P = 0.52). Univariant and multivariant analyses identified rPS group (Hazard Ratio 8.68, P = 0.006) and resection margins (Hazard Ratio 6.29, P = 0.004) to be independently associated with disease-free survival. ConclusionsWe have demonstrated that achieving R0/R1 resection is feasible. Oncological outcomes are favorable for primary tumors, whereas recurrent tumors exhibit early recurrences. Consideration of resection of recurrent pelvic STS should involve a careful multidisciplinary evaluation.

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.

Oncologic outcomes of Complex Primary Pelvic Soft Tissue Sarcoma, tumor biology, or surgical constraints of the true pelvis.

Background: Pelvic soft tissue sarcomas are a rare group of tumours whose management is distinctively complex and less reported upon. Surgical resection is the main curative option. However, this can be challenging due to anatomical constraints of the true pelvis, with the proximity to various confined vital structures, along with the ability of tumour for trans-compartmental spread through various anatomical hiatus into thigh, buttock and perineum.

Application of Silicone-Filled Vaginal Spacers for Pediatric Proton Therapy

Tissue spacers, including vaginal wall spacers, are used in a number of cancer diagnoses including soft tissue sarcomas, prostate cancer, cervical and uterine cancers. In proton therapy, the benefit of tissue spacers can be even greater as the device can serve as a beam stopper where protons reach their end of range in the material of the spacer instead of adjacent tissues.Commercially available hollow vaginal spacers which come in sizes ranging from 1.46 cm to 3.65 cm in diameter were filled with air-free silicone in a custom-made vacuum chamber. Two adolescent patients with pelvic soft tissue sarcomas receiving proton therapy were CT-simulated with and without a vaginal spacer. The relative stopping power of silicone was measured in a water tank to estimate the water equivalent thickness from 1.56 cm to 3.91 cm used in the treatment planning system for dosimetric comparisons. The dosimetric advantages of the silicone-filled vaginal spacer were investigated in three different dosimetric scenarios: (1) no vaginal spacer, (2) hollow vaginal spacer, (3) silicone-filled vaginal spacer in terms of plan quality and sparing of contralateral vaginal wall during primary and boost phases for two patients.While the target coverages remained comparable for the phase I (CTV, Rx = 36 Gy) and the phase II (GTV, Rx = 59.4 Gy), the dose distributions of ipsilateral and contralateral vaginal walls varied across these scenarios. After the phase II, the dosimetric sparing of contralateral vaginal wall was chiefly achieved in the patient A as the mean dose was 8.4 Gy with the silicone-filled spacer, and 17.1 Gy with hollow spacer, and 30.8 Gy with no spacer. However, due to the size and location of the tumor relative to the vagina, the sparing of contralateral vaginal was not observed in the patient B. While the patient A had a unilateral tumor with smaller GTV volume (23.3 cc) irradiated by straight lateral and posterior beams, the patient B had bilaterally located larger GTV volume (342.2 cc) covered by two posterior oblique beams.The study suggested that when the vagina is adjacent but located distal to the tumor, a significant dose reduction can be achieved with the insertion of a silicon-filled vaginal spacer.

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

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

The impact of postoperative radiological surveillance intensity on disease free and overall survival from primary retroperitoneal, abdominal and pelvic soft-tissue sarcoma

AimThis observational study aimed to evaluate the impact of intensity of radiological surveillance on survival following resection of retroperitoneal sarcoma. MethodRetrospective cohort study of patients undergoing primary resection of soft tissue sarcoma arising in the retroperitoneum, abdomen or pelvis at a single, high-volume sarcoma centre. Intensity of follow-up regimes up to 5 postoperative years were categorized as ‘European Society for Medical Oncology (ESMO) compliant’ (intense), or ‘non-ESMO compliant’ (less-intense). The primary outcome measure was overall survival (OS). The secondary outcome measures were disease-free survival (DFS) and reoperation rate. Analyses were stratified by high (grade 2 or 3) or low (grade 1) tumour grade. ResultsOf 168 patients, 67.1% had high-grade and 32.9% had low-grade disease. Overall, 40.0% of patients had ESMO-compliant radiological follow-up (high-grade:25.7%, low-grade:66.7%). 41.7% of patients died and 48.2% suffered local or distant recurrence by cessation of follow up. Upon univariable analysis for high-grade tumours, ESMO compliance reduced DFS (p = 0.066) but had no impact on OS. There was no significant difference in the reoperation rate in patients with ESMO-compliant and non-compliant follow-up (p = 0.097). In low-grade tumours, ESMO compliance significantly reduced DFS (p < 0.001), but without effecting OS. In risk-adjusted models for high-grade tumours, ESMO compliant follow-up was associated with reduced OS (HR:3.47, 1.40–8.61, p = 0.007) and no difference in DFS. In low-grade tumours, there was no association between overall ESMO compliance and OS or DFS. ConclusionThis study did not find a benefit for high-intensity radiological surveillance and overall survival in patients undergoing primary resection for high or low-grade retroperitoneal sarcoma.

Multidisciplinary retroperitoneal and pelvic soft-tissue sarcoma case conferences: the added value that radiologists can provide.

Clinical Vignette: A 50-year-old woman presents to the emergency department with increasing abdominal pain. Abdominal computed tomography imaging reveals an expanded inferior vena cava-filling defect that is suspicious for a retroperitoneal sarcoma, possibly a primary leiomyosarcoma of the inferior vena cava. The surgery team discusses the case with the radiologist, and all agree that there are multiple challenges with obtaining a tissue diagnosis and determining resectability. Thus, it is decided that this patient should be discussed at a multidisciplinary case conference. In the present article, we feature a case-based scenario focusing on the role of the radiologist in this type of multidisciplinary team.

Recurrence and survival analysis of resected soft tissue sarcomas of pelvic retroperitoneal structures.

The purpose is to determine the clinicopathologic factors related to survival and recurrence of primary resected pelvic soft tissue sarcomas (STS). Demographic/clinical variables were recorded. Thirty-five pts were identified. Median follow-up was 24.2 months. There were 23 (65.7%) high/intermediate-grade and 12 (34.3%) low-grade tumors included in the final analysis. Eight patients (22.9%) received neoadjuvant therapy. Margins were grossly negative in 27 (77.1%, 17-R0, 10-R1) and grossly positive (R2) in 8 (22.9%). Adjuvant therapy was used in 13 patients (37.1%). The 2- and 3-year RFS was 56.5% and 51.3%, with 14 patients recurring at a median time of 16 months (6-local, 8-distant). All distant recurrences were in high-grade tumors. There were no differences in RFS for margins (R0 vs. R1), neoadjuvant/adjuvant therapy, size (≥10 vs. <10 cm) or gender. High/intermediate-grade tumors had worse RFS (P < 0.008). The 2- and 3-year OS was 80.9%. OS was improved for R0/R1 resection (P < 0.001). Resection to R0/R1 margin was a significant predictor of improved OS (P = 0.001). High/intermediate-grade lesions were associated with worse OS and RFS. Resection to gross negative margins was the only independent predictor of OS. Adjuvant therapy may be reserved for high-grade lesions due to increased metastatic potential. J

Body CT in unprovoked PE – a worthwhile fishing trip?

Purpose Cancer and pulmonary embolism (PE) have an established causal relationship but there is a paucity of data on the incidence of occult cancer in patients with PE and no other risk factors. The National Institute of Health and Care Excellence (NICE) guidelines recommend further investigation with abdomino-pelvic computed tomography (CT AP) increasing demand on radiology departments. We aimed to determine if this is an appropriate use of resources by ascertaining occult cancer prevalence, type and stage at diagnosis in such cases. Methods and materials Patients with unprovoked PE diagnosed on CTPA and who subsequently had CT AP were identified from the radiology information system (RIS)/picture archiving and communication system (PACS) for the two-year period January 2013 to December 2014. The following were recorded: age, sex, diagnosis of a cancer, and if present the type and stage. Results Of patients with a positive CTPA and subsequent CT AP, 7.4% had occult cancers (ten cancers in 135 patients). The detected cancers were pancreatic, colonic, bladder, prostate, hepatic, pelvic soft tissue sarcoma and haematological. Of these, 70% were locally advanced or metastatic cancers. Age range: 64–92. No specific factors were identified to enable risk stratification of these patients. Conclusion Occult cancers in patients with PE are often advanced with a poor two-year survival rate. However, a small proportion are treatable and investigation in PE patients with no provoking factors should be considered. No risk factors are identified to risk stratify the cancer detection scans.

Resection of Soft Tissue Tumors Extending Through the Obturator Ring

Pelvic soft tissue sarcomas are rare tumors often presenting larger than other soft tissue sarcomas and can extend into the thigh through various anatomic routes. Surgical resection is the main modality of curative treatment. En bloc tumor excision with wide, negative margins may reduce the risk of local recurrence. Soft tissue sarcomas extending through the obturator foramen create unique challenges to operative management. This case report describes 2 cases of lipomatous lesions that extend through the obturator foramen, presenting as dumbbell-shaped lesions with large intra- and extrapelvis portions. One possible surgical approach performed in both patients is detailed with long-term follow-up. Postoperatively, 1 incidence of infection was reported. Functional outcomes were acceptable, with full restoration of ambulation without assistive devices in both cases and no hernia observed. Oncologic outcomes included locoregional recurrence in 1 patient at 24 months outside the radiation field. The ideal primary treatment for all localized soft tissue sarcomas, including those extending through the obturator foramen, is resection. However, the unique subgroup of obturator ring soft tissue sarcomas has undefined outcomes and complications. The authors' goal was to achieve en bloc resection with wide negative margins while preserving ipsilateral limb function. The surgical approach described in this case study offers a description of feasibility and discussion of theoretical and observed complications.

Optimal surgical treatment and urological outcomes in boys with pelvic and urogenital rhabdomyosarcomas and soft tissue sarcomas

Soft tissue sarcomas (STS) of pelvic origin in boys often involve the urogenital organs. The optimal extensiveness of radical surgery has long been an issue of discussion, since exenterative surgeries result in severe urogenital adverse effects. We conducted a retrospective review of patients with pelvic STS treated in two regional center hospitals and assessed the radicality of surgery and the functional outcome of the bladder. Medical records and surgical reports of nine cases (embryonal rhabdomyosarcoma 6, malignant triton tumor 2, suspected rhabdomyosarcoma 1) treated within 1997-2012 were reviewed. Site of origin was prostate in seven, retroperitoneal in two. Average follow-up period was 96months. All cases were subjected to neoadjuvant chemotherapy. Response was PR in four, SD in two, and PD in two. Radical surgery resulted in gross total resection in eight, and partial resection in one. Three underwent cystoprostatectomy, two cases underwent prostatectomy, and bladder-preserving tumor resection was carried out in four cases. At the last follow-up, three retained a functional bladder. Two required augmentation cystoplasty with intestinal conduits. The majority of the on-going clinical trials recommend conservative surgery for bladder/prostate rhabdomyosarcoma, and to preserve the bladder function particularly in chemosensitive tumors. Some other groups, however, advocate the importance of radical surgery to prevent local relapse. These reports include heterogenous group of patients in the cohort, and therefore it is difficult to draw a conclusion of which approach truly contributes to the survival of the patients better. Future studies should evaluate bladder and sexual function objectively to establish reliable evidence regarding the benefit and adverse effects of different surgical approaches. These data would be informative to optimize the treatment balance for children with pelvic rhabdomyosarcomas.

Oncological outcome of patients with deeply located soft tissue sarcoma of the pelvis: A follow up study at minimum 5 years after diagnosis

The treatment of pelvic soft tissue sarcomas (STS) presents one of the most challenging problems in musculoskeletal oncology because of the complex anatomy of the pelvis, late diagnosis and large tumor size. Our study was designed to determine the outcome and prognostic factors for survival and local recurrence in patients with pelvic STS located deep to the fascia and deemed suitable for curative surgical treatment. Ninety consecutive pelvic STS patients with at least 5-year possible follow-up from diagnosis were studied. Mean age at diagnosis was 54 years. Mean follow-up and tumor size were 69 months and 13 cm, respectively. Histological grades were grade 3 in 51, grade 2 in 22 and grade 1 in 17 patients. Tumor locations were extra-pelvic or outside pelvic brim (n=67), intra-pelvic or within pelvic brim (n=10), and combined or involving both outside and within pelvic brim (n=13). Surgical treatment was excision in 84 patients and hindquarter amputation in 6 patients. In 84 patients who underwent excision, surgical margin was wide in 21 patients, marginal in 33, and intralesional in 30. Radiotherapy was used for all high grade tumors. Disease-specific survival was 53.3% at 5 years. Local recurrence occurred in 23%. Development of local recurrence was related to surgical margin (p=0.03). Local recurrence, tumor histological grade and metastasis at diagnosis independently influenced disease-specific survival (p=0.0008, p<0.0001, p=0.02, respectively). The patients with high grade tumors and positive surgical margins represent a particular group with high risk of local recurrence even with radiotherapy.

9402 ORAL Clinical Outcomes of Pelvic Soft-tissue Sarcomas Treated With Surgery and Radiotherapy

9402 ORAL Clinical Outcomes of Pelvic Soft-tissue Sarcomas Treated With Surgery and Radiotherapy

An unusual case of female hypospadias associated with a pelvic mass

Female hypospadias is a rare malformation. We report on an unusual case that presented with a urethral dimple in the perineum in association with a pelvic soft tissue sarcoma compressing and displacing the urethra. The diagnosis was made by cystoscopy, and, as the patients remained asymptomatic, no treatment was eventually required for her urologic malformation. This is, to our knowledge, the first reported case of female hypospadias associated with a perineal urethral dimple. The possible pathogenesis of the malformation is discussed also in relation to the simultaneous presence of a pelvic mass.

Adult Pelvic Sarcomas: A Heterogeneous Collection of Sarcomas?

Introduction. Adult pelvic soft tissue sarcomas are a rare group of heterogeneous malignancies. These sarcomas differ from extremity and trunk soft tissue sarcomas in presentation, characteristics and response to treatment. Methods. A retrospective analysis of patient and tumor characteristics, treatment and prognosis and prognostic factors was performed. Results. Between 1977 and 1997, a total of 33 adult patients with soft tissue sarcomas involving the pelvis but excluding uterine leiomyosarcoma were identified. Leiomyosarcomas (18), including six GIST, and rhabdomyosarcomas (eight) were the most commonly seen tumors. At first presentation, nine patients already had metastases. The mean follow-up was 52 months (1–200). Recurrences developed in 15 of the 24 cases (63%) with tumors without metastases at first presentation; in six (25%) recurrence was locally only, in nine distant metastases occurred. The nine patients with metastatic disease at first presentation died of the disease, while eight of the 24 patients with localized disease at presentation died. One patient died of an unrelated cause, four were alive with disease, and 11 patients were alive and free of disease. The only identifiable prognostic factor of disease-free interval and overall survival was histological grade. Conclusion. Soft tissue sarcomas of the pelvis appear to be associated with increased rate of metastasis at the time of diagnosis and higher rates of local recurrence. In this study, multi-modality treatment for most primary tumors did not show a significant benefit in recurrence rate, DFI and OST, when compared to single modality approach. Although the number of patients in this study is small, and different types of sarcomas were studied, the only identifiable predictor for survival was low histological grade of the tumors. The differences of this heterogeneous group of pelvic sarcomas with retroperitoneal, trunk and extremity sarcomas should be taken into consideration in the management of these sarcomas.

Temporary relocation of testes to the anterior abdominal wall before radiation therapy of the pelvis or perineum

Recent advances in the treatment of pelvic malignancies in children has resulted in an increased life expectancy. In the past, treatment of soft tissue sarcomas with simple surgical excision resulted in a recurrence rate of approximately 75%. Combination of chemotherapy, radiotherapy, and surgery have significantly altered the outcome of advanced pelvic soft tissue sarcomas. With the improved survival rate of patients treated with combination therapy, sterility secondary to radiation therapy has become an issue. As little as 600 rads to the gonads may result in sterility later in life. To alleviate this problem, relocating the gonads from the field of radiation has been suggested. In this report, we present a novel approach in which the testes are wrapped in SILASTIC® (Dow Corning, Midland, MI) sheaths and are relocated temporarily into the anterior abdominal wall away from the radiation field. This alternative surgical approach should be considered in boys who are afflicted with a pelvic/perineal malignancy requiring radiation therapy. J Pediatr Surg 37:1232-1233. Copyright 2002, Elsevier Science (USA). All rights reserved.

54 Use of intraoperative electron beam radiation therapy(IOERT) in the management of retroperitoneal and pelvic soft tissue sarcomas

54 Use of intraoperative electron beam radiation therapy(IOERT) in the management of retroperitoneal and pelvic soft tissue sarcomas