High dose (54 Gy) pre-operative helical tomotherapy for retroperitoneal liposarcoma: Results of a phase II multicenter study.

PURPOSE: To evaluate efficacy and feasibility of high-dose intensity-modulated radiotherapy (RT) with pre-operative helical tomotherapy, delivering 54 Gy/30 fractions in patients with retroperitoneal liposarcomas (RPLS). MATERIALS AND METHODS: Patients with operable, biopsy-proven, RPLS were included in this phase II multicenter study (ClinicalTrials.gov: NCT01841047). The primary objectives were to analyze loco-regional relapse free survival (LRFS), overall survival (OS) and toxicities, graded according to CTCAE V3.0. RESULTS: From April 2009 to September 2013, 48 patients were included. Histological types were: 20 well differentiated and 28 dedifferentiated liposarcomas. Median clinical target volume (CTV) was 2570 cc (range, 230-8734 cc). The radio-surgical schedule was completed as planned in all patients apart from one. A monobloc wide excision was achieved for all patients. Surgical margins were R0 (16; 34%), R1 (28; 60%), R2 (2; 4%) or missing (1, 2%).With a median follow-up of 5.5 years, 3-year LRFS rate was 74.2% (95%CI: [59.1%; 84.5%]). At 5 years, cumulative incidence of loco-regional relapse for well differentiated and dedifferentiated RPLS was 10% and 18%, respectively. The 5-year OS was 73.9% [95%CI: 58.7-84.3%]. During RT, the most common grade 3-4 adverse events were hematological (N = 20; 41.6%). After surgery and during follow-up, 17 patients (35.4%) presented a grade 3-4 toxicity. Two patients (4.1%) died due to a duodenal toxicity. Nine second cancers were observed. CONCLUSION: From this phase II trial of preoperative RT in RPLS patients, the dose level proposed cannot be considered safe, leading to non-negligible toxicity and second cancers rates. Our results, combined with STRASS-1 study, suggest that the ideal indication of RT for patients with RPLS still remains to be determined.

Six Surgical Stages in the Resection of Primary Right Retroperitoneal Liposarcoma: A Standardized Comprehensive Approach.

BACKGROUND: Surgery is the treatment mainstay in retroperitoneal sarcoma (RPS), a frontline comprehensive approach based on tumor removal en bloc with adherent viscera is mandatory especially for liposarcoma, where the normal retroperitoneal fat is undistinguishable from the well-differentiated tumor component.1-5 In this video, a reproducible and standardized six-stage approach to a primary right retroperitoneal liposarcoma is presented. PATIENT AND METHODS: A 23-cm right retroperitoneal, well-differentiated liposarcoma was diagnosed in a 68-year-old female patient in December 2021. The tumor involved the right kidney and adrenal gland; displacing anteriorly the right colon, the duodenum, and the pancreatic head; and invading part of the ipsilateral psoas muscle. After the publication of the STRASS trial and STREXIT results,6,7 neoadjuvant radiotherapy was delivered to a total dose of 50.4 Gy in 28 fractions with stable disease. Virtual 3D reconstruction of regional anatomy by Visible Patient was performed preoperatively. RESULTS: The patient underwent right retroperitoneal mass resection en bloc with ipsilateral kidney and adrenal gland, colon, psoas muscle, and portion of ipsilateral diaphragm. Of note, the resection of the psoas muscle was performed to obtain a safe posterior margin and accomplish a better clearance of fat of the posterior abdominal wall. This can be limited to the psoas fascia whenever the tumor is not adherent to it. A six-stage approach was performed, as described in the supplementary video file. CONCLUSIONS: RPS resection is complex and requires a broad range of surgical expertise. A staged approach that can be followed in virtually all cases is highly recommended to achieve an optimal tumor resection.

[Retroperitoneal Dedifferentiated Liposarcoma with No Recurrence after 5 Years of Postoperative Radiation Therapy --A Case Report-].

A 49-year-old woman presented to our hospital with right lower back pain and epigastric pressure. A computed tomographic scan showed a 12×7×20 cm retroperitoneal mass comprising fatty components and contrast areas around the right kidney. Based on the results, a right retroperitoneal liposarcoma was suspected. Thus, right retroperitoneal tumor resection combined with right kidney resection was performed. Instances of tumor adhesion were found in the ascending colon, duodenum, and the iliopsoas muscle, which could be dissected ; therefore, combined resection of the intestinal tract was not performed. The resected tumor was found to be mixed with dedifferentiated and well-differentiated components and was diagnosed as dedifferentiated liposarcoma. Due to the presence of positive margins, the patient received 50 Gy in 25 fractions of radiation therapy to the right side of the retroperitoneum as postoperative adjuvant therapy. During the irradiation period, vomiting and anorexia were observed as adverse events. Five years have passed since the surgery, and no local recurrence or late complications due to radiation have been observed. Although dedifferentiated liposarcoma is a highly malignant histological type with a very high local recurrence rate, no adjuvant therapy has been established. Some reports have suggested that postoperative radiation therapy for retroperitoneal sarcoma is effective in terms of survival and local control. However, there are no reports of prospective clinical trials, and the evidence is expected to widen in the near future.

Vanished MDM2 amplification in multiple recurrences of an irradiated poorly differentiated sarcoma with amplified TRIO::TERT fusion gene.

Among sarcomas, MDM2 amplification is usually a molecular hallmark of well-differentiated liposarcoma and dedifferentiated liposarcoma (DDLPS) and occasionally a secondary genetic anomaly in other sarcomas. Histological evaluation and FISH analysis showing MDM2 amplification led to the diagnosis of DDLPS for a tumor located on the left arm of a 71-year-old patient. The patient was treated by adjuvant radiotherapy (RT) but the tumor recurred soon after. Array-comparative genomic hybridization and targeted RNA/DNA sequencing of the primary tumor and of four recurrences were done. Strikingly, the MDM2 amplification observed in the primary tumor had vanished in the recurrences. In contrast, other rearrangements, such as amplification of the genes TRIO and TERT as well as TRIO::TERT fusion were detected retrospectively in the primary tumor and in all the recurrences. The transitory nature of the MDM2 amplification raised the hypothesis that RT was active on cells that contained MDM2 amplification but not on other tumor cells with only the TERT and TRIO alterations. In contrast to MDM2 amplification, the TRIO::TERT amplified fusion was stable over time. The detection of this fusion was crucial in the analysis of the diagnostically challenging last tumor; it allowed to determine that it was a fourth recurrence, instead of a new independent tumor. It also suggested the diagnosis undifferentiated pleomorphic sarcoma rather than DDLPS. The TRIO::TERT fusion is not well explored. The current study shows that its role in sarcomas, with or without MDM2 amplification, should be more extensively researched.

Comparison of the anti-cancer activity of 5-aminolevulinic acid-mediated photodynamic therapy after continuous wave and pulse irradiation in different histological types of canine mammary sarcoma tumors.

Canine mammary sarcoma tumors (CMST) are the most aggressive tumors with poor prognosis in dogs. Due to inadequate treatment options for CMST, recent studies have focused on alternative treatment strategies. We previously determined the optimized protocol of 5-ALA-based photodynamic therapy (PDT) in canine liposarcoma. However, its molecular mechanisms in the treatment of different histological types of CMST remain unclear.In this context, we, for the first time, assessed 5-aminolevulinic acid (5-ALA)-PDT-mediated anti-cancer activity and its molecular mechanism after continuous wave (CW) and pulse radiation (PR) on three different histological types (liposarcoma, chondrosarcoma, and osteosarcoma) of CMST cells by WST-1, Annexin V, ROS, acridine orange/propidium iodide staining, RT-PCR, and western blot analysis.Our findings showed that 5-ALA/PDT significantly suppressed the proliferation of CMST cells (p < 0.01) and induced apoptosis via increased ROS level and overexpression of Caspase-9 and Caspase-3 mRNA and cleaved protein levels in especially liposarcoma and chondrosarcoma cells following CW and PR irradiation at 9 J/cm2. However, the response of CMST cells to 5-ALA was different upon CW and PR irradiation due to differences in their origin.Collectively, our findings provided the first evidence that 5-ALA-based PDT could be used as an alternative treatment strategy, especially liposarcoma and chondrosarcoma. However, further in vitro and in vivo studies are required to elucidate the underlying molecular mechanism of the efficacy of 5-ALA in CMST cells at the molecular level.

Preoperative Radiotherapy in Patients With Primary Retroperitoneal Sarcoma: EORTC-62092 Trial (STRASS) Versus Off-trial (STREXIT) Results.

OBJECTIVE: The aim of the present study was to compare the effect of radiotherapy (RT) on abdominal recurrence-free survival (ARFS) in patients with primary retroperitoneal sarcoma treated in the EORTC-STBSG-62092 (STRASS) phase 3 randomized controlled trial (STRASS cohort) and off-trial (STREXIT cohort) and to pool STRASS and STREXIT data to test the hypothesis that RT improves ARFS in patients with liposarcoma. BACKGROUND: The STRASS trial did not show any difference in ARFS between patients treated with preoperative radiotherapy+surgery (RT+S) versus surgery alone (S). METHODS: All consecutive adult patients not enrolled in STRASS and underwent curative-intent surgery for a primary retroperitoneal sarcoma with or without preoperative RT between 2012 and 2017 (STRASS recruiting period) among ten STRASS-recruiting centres formed the STREXIT cohort. The effect of RT in STREXIT was explored with a propensity score (PS)-matching analysis. Primary endpoint was ARFS defined as macroscopically incomplete resection or abdominal recurrence or death of any cause, whichever occurred first. RESULTS: STRASS included 266 patients, STREXIT included 831 patients (727 after excluding patients who received preoperative chemotherapy, 202 after 1:1 PS-matching). The effect of RT on ARFS in STRASS and 1:1 PS-matched STREXIT cohorts, overall and in patients with liposarcoma, was similar. In the pooled cohort analysis, RT administration was associated with better ARFS in patients with liposarcoma [N=321, hazard ratio (HR), 0.61; 95% confidence interval (CI), 0.42-0.89]. In particular, patients with well-differentiated liposarcoma and G1-2 dedifferentiated liposarcoma (G1-2 DDLPS, n=266) treated with RT+S had better ARFS (HR, 0.63; 95% CI, 0.40-0.97) while patients with G3 DDLPS and leiomyosarcoma had not. At the current follow-up, there was no association between RT and overall survival or distant metastases-free survival. CONCLUSIONS: In this study, preoperative RT was associated with better ARFS in patients with primary well-differentiated liposarcoma and G1-2 DDLPS.

The role of standard and novel radiotherapy approaches in management of retroperitoneal sarcomas.

Primary non-metastatic retroperitoneal soft tissue sarcoma patients can be cured by radical surgery. However there remains a risk for patients to develop a local recurrence. To minimize this risk, patients with low grade liposarcomas might benefit from preoperative radiotherapy. This review summarizes all issues that should be considered for the irradiation of patients with retroperitoneal soft tissue sarcoma.

Clinical Impact of External Beam Radiotherapy for Surgically Resected Primary Retroperitoneal Liposarcoma.

INTRODUCTION: EORTC-62092 (STRASS) was a phase 3, randomized study that compared surgery alone versus surgery plus neoadjuvant radiotherapy (RT) for retroperitoneal sarcomas. RT was not associated with improved abdominal recurrence-free survival, the primary outcome measure, although on subanalysis, there may have been benefit for well-differentiated (WD) liposarcoma. This study investigated the real-world use and outcomes of RT (neoadjuvant and adjuvant) for the management of retroperitoneal liposarcoma. METHODS: We queried the National Cancer Database (NCDB) (2004-2017) for patients with nonmetastatic, primary retroperitoneal liposarcoma treated with resection with or without RT (n = 3911). Patients were stratified by treatment type and histology [WD (n = 2252), dedifferentiated (DD) (n = 1659)]. Propensity score (PS) matching was used before comparison of treatment groups. Overall survival (OS) was the primary outcome measure. RESULTS: Median follow-up time was 4.1 years, and median OS was 10.7 years. There was no association between RT and OS for either WDLPS or DDLPS cohorts. We performed a subgroup analysis of neoadjuvant RT only, similar to STRASS. For WDLPS after PS matching (n = 208), neoadjuvant RT was not associated with OS (hazard ratio [HR] 1.01, p = 0.0523) but was associated with longer postoperative hospital stay (p = 0.012). For DDLPS after PS matching (n = 290), neoadjuvant RT was not associated with OS (HR 1.02, p = 0.889). For both WD-LPS and DD-LPS, utilization of neoadjuvant RT was associated with treatment at high-volume (≥ 10 cases/year) and academic/network facilities. CONCLUSIONS: For primary retroperitoneal liposarcoma treated with surgical resection, radiotherapy was not associated with an overall survival benefit in this propensity-matched, adjusted analysis of the NCDB.

Low and moderate grade retroperitoneal liposarcoma: Is adjuvant radiotherapy associated with improved survival in patients undergoing R1 resection?

BACKGROUND: Few studies evaluate the efficacy of adjuvant radiotherapy (aXRT) in patients with retroperitoneal liposarcoma undergoing resection to histologically positive (R1) margins. METHODS: We queried the National Cancer Database to identify patients undergoing R1 resection for localized, large (>5 cm) low and moderate grade retroperitoneal liposarcoma between 2004 and 2016. Kaplan Meier method was used to compare overall survival (OS) for patients receiving aXRT to a 1:2 propensity-matched cohort of patients undergoing resection alone. RESULTS: A total of 322 (76.5%) patients underwent R1 resection alone, while 99 (23.5%) underwent resection followed by aXRT. The 99 receiving aXRT were successfully 1:2 propensity-score matched to 198 undergoing resection alone. There was no difference in 5-year OS between matched cohorts (69.7% vs 76.2%, p = 0.40). CONCLUSIONS: In patients undergoing R1 resection of moderate- and well-differentiated retroperitoneal liposarcoma, use of aXRT is not associated with an improvement in OS.

Adjuvant radiotherapy in the treatment of dedifferentiated liposarcoma of the spermatic cord: a rare entity.

Dedifferentiated liposarcoma (DDL) of the spermatic cord is a very rare entity in which management is remarkably controversial due to scarce literature. Although the actual standard of care is surgery via radical inguinal orchiectomy, adjuvant therapies like radiotherapy have demonstrated improved local control, particularly in cases with higher risk for local recurrence and worse prognosis. The role of adjuvant chemotherapy remains questionable in this subset of patients. On literature review, the most important prognostic factors for survival outcomes were surgical margin status, histological grade and the presence of metastases prior to the initial surgery. In this report, we discuss the case of a 59-year-old man with DDL of the spermatic cord that was treated with surgery followed by adjuvant radiotherapy. We also provide a comprehensive literature review about the management of this entity.

Cutaneous dystrophic calcification following high-dose radiotherapy for a liposarcoma.

Cutaneous dystrophic calcification as a late change of radiation therapy is a rarely reported finding. Initially, it was almost exclusively described as occurring on the chest wall in breast cancer patients but has since been described in several other malignancies. We describe the first reported case of radiotherapy-induced calcinosis cutis occurring at the site of a previous liposarcoma. Review of the literature including risk factors, similar cases, pathophysiology, and management is also explored.

Characterising the immune microenvironment in liposarcoma, its impact on prognosis and the impact of radiotherapy.

BACKGROUND AND OBJECTIVES: Limited literature exists examining the immune microenvironment in liposarcoma, particularly with regard to the impact of radiotherapy. A major problem is the lack of scoring system for the tumour-infiltrating lymphocytes (TILs) in sarcoma. This study aims to describe the immune environment pre- and postradiotherapy and identify the optimal immune infiltrate scoring system for sarcoma. METHODS: Thirty-nine paired tissue samples (pre- and postradiotherapy) from patients with liposarcoma were scored by two pathologists for TILs using pre-existing systems (for breast cancer and melanoma) and compared for interobserver reliability. Immunohistochemical staining was performed for various immune markers. RESULTS: The TIL scoring system for breast cancer yielded perfect agreement (κ = 1.000). 21% of patients had increased TILs after radiotherapy, 87.5% of whom had dedifferentiated liposarcoma. Immune suppressor expression was increased frequently after radiotherapy (CD68 increased in 59.4%, PD-L1 increased in 25%). Immune effector expression (CD8) was unchanged in 84.4%. CONCLUSIONS: Breast cancer TIL scoring is reproducible in liposarcoma and has high interobserver reliability. Radiotherapy was observed to have a limited impact on immune effectors but seemed to have more impact in upregulating immune suppressors, suggesting radiotherapy may contribute to disease control through immunomodulatory effects. Dedifferentiated liposarcoma represents a uniquely responsive subtype.

The importance of the margin of resection and radiotherapy in retroperitoneal liposarcoma.

BACKGROUND: Prior studies evaluating the impact of adjuvant or neoadjuvant radiotherapy on clinical outcomes in retroperitoneal liposarcoma have been underpowered. METHODS: We queried the National Cancer Database for patients undergoing resection of retroperitoneal liposarcoma from 2004 to 2016. Cox proportional hazards modeling stratified by tumor size was used to identify factors associated with overall survival. RESULTS: 4018 patients met inclusion criteria. 251 had small (<5 cm), 574 intermediate (5-10 cm), and 3193 large (>10 cm) tumors. Positive surgical margins were correlated with risk of death across all tumor size categories (<5 cm HR 2.33, CI [1.20, 4.55]; 5-10 cm HR 1.49, CI [1.03, 2.14]; >10 cm HR 1.30, CI [1.12, 1.51]). Adjuvant radiotherapy was associated with improved survival for patients with large tumors only (HR 0.75, CI [0.64, 0.89]). CONCLUSIONS: In retroperitoneal liposarcoma, adjuvant radiation is associated with improved survival only for patients with tumors larger than 10 cm. Radiation should be used sparingly in patients with smaller tumors. SUMMARY: The use of radiotherapy in the management of retroperitoneal sarcoma remains controversial. We isolated retroperitoneal liposarcomas only and identified a survival benefit from radiotherapy treatment only in tumors larger than 10 cm and only in the adjuvant setting.

Toxic epidermal necrolysis after radiotherapy for pleomorphic liposarcoma.

Toxic epidermal necrolysis (TEN) and Stevens-Johnson syndrome (SJS) are life-threatening, cutaneous reactions often associated with culprit drugs. A growing body of knowledge has deepened our understanding of the pathophysiology and clarified mechanisms such as drug-specific cytotoxicity mediated by T-cells, genetic linkage with HLA and non-HLA genes, TCR restriction, and cytotoxicity mechanisms. Physicians should broadly consider the etiology of SJS/TEN in order to better understand treatment strategies as well as identify which patients may be at risk for developing this condition. Mechanisms for how radiotherapy and rare malignancies may contribute to the development of TEN and SJS have been proposed.

Significance of intraoperative radiation therapy and high cumulative radiation doses in retroperitoneal soft tissue sarcoma.

INTRODUCTION: In retroperitoneal soft tissue sarcoma (STS) local recurrence (LR) rates remain high despite more aggressive surgical approaches. Since wide resection margins cannot be achieved in all patients, application of intraoperative radiation therapy (IORT) has been frequently discussed. Still, the significance of IORT in multimodal treatment of retroperitoneal STS remains unclear. MATERIAL AND METHODS: Patients undergoing resection of primary or recurrent retroperitoneal STS at the University of Heidelberg Department of General, Visceral and Transplantation Surgery were retrospectively analyzed. Univariate Kaplan-Meyer and multivariate Cox regression analyses were performed to identify predictors of LR-free survival and to investigate the impact of IORT and high cumulative radiation doses. Analyses with propensity-score matched subgroups for IORT and cumulative radiation dose were performed to control for selection bias. Subgroup analyses for patients with retroperitoneal liposarcoma were likewise performed. RESULTS: 272 patients were identified. Recurrent tumors, histology of dedifferentiated liposarcoma or unclassified sarcoma and microscopically incomplete resection were associated with decreased LR-free survival. In liposarcoma, only recurrent and dedifferentiated tumors were confirmed as poor prognostic factors concerning LR. IORT and cumulative radiation doses exceeding 60 Gy did not influence LR rates (estimated 5-year LR-free survival: IORT: 39%, non-IORT: 46%; p = 0.79). CONCLUSION: In this retrospective evaluation, additional application of IORT does not significantly influence oncological outcome in retroperitoneal soft tissue sarcoma. Randomized trials are needed to clarify the benefit of IORT.

Radiation and Its Impact on Local Recurrence in Extremity and Trunk Well-Differentiated Liposarcomas.

Patients with well-differentiated liposarcomas (WDLPS) of the extremity and trunk are treated primarily with surgical resection, with radiation used for a number of anecdotal reasons, including large size and positive margins. In this study, we evaluate the appropriate role for radiation in these tumors. A retrospective chart review of patients with extremity and trunk soft tissue liposarcomas referred to a free-standing cancer center from January 1995 to December 2011 was performed. One hundred eighty-three patients with extremity and trunk soft tissue WDLPS were identified: 61 per cent were female, median age was 60 years (range, 19-84 years) and 2 per cent had a focal area of dedifferentiation, margin status was positive in 57 per cent. Fourteen per cent of patients received radiation. Fifty patients developed recurrent disease; 28 per cent of these received radiation. Median time to recurrence was 18 years (range, 0.7-22 years). Of the 50 patients who recurred, 14 (28%) received radiation. Radiation was associated with decreased second recurrence when administered for recurrent disease (P = 0.03). On multivariable analysis, tumor size ≤ 10 cm (P = 0.014) and anatomically difficult area of resection (P = 0.008) were predictive of increased risk of recurrence. Older age (P = 0.02), dedifferentiated liposarcomas (P < 0.001), and difficult area of resection (P = 0.02) were associated with the administration of radiotherapy. Administration of radiation therapy was not associated with decreased time to recurrence in WDLPS overall; however, it should be considered in patients with recurrent disease.