Incidence of skeletal-related events in patients with Ewing sarcoma: An observational retrospective study in Japan

BACKGROUND

Skeletal-related events (SREs), including the pathological fracture, surgical treatment or radiation of bone lesions, malignant spinal cord compression, hypercalcemia, are important considerations when managing metastatic bone tumors; however, owing to their rarity, the incidence of SREs in patients with Ewing sarcoma remains unknown.

METHODS

We retrospectively reviewed the clinical data from 146 patients with Ewing sarcoma treated at a single institution from 2005 to 2019. The median age at diagnosis was 22.7 years. Fifty patients (34.2%) had metastatic disease at diagnosis. The primary outcome was the SRE-free rate among patients with Ewing sarcoma. Moreover, we identified the risk factors for SREs using univariate or multivariate analyses.

RESULTS

During the observational period (median, 2.6 years), SREs occurred in 23 patients. Radiation to the bone, malignant spinal cord compression, and hypercalcemia were documented as the initial SREs in 12 patients (52.2%), 10 patients (43.5%), and one patient (4.3%), respectively. The SRE-free rate was 94.2 ± 2.0, 87.3 ± 3.0, and 79.6 ± 3.8% at 1, 2, and 3 years after the initial visit, respectively. Multivariate analysis revealed bone metastasis at diagnosis (hazard ratio [HR] = 4.41, p = 0.007), bone marrow invasion (HR = 34.08, p < 0.001), and local progression or recurrence after definitive treatment (HR = 3.98, p = 0.012) as independent risk factors for SREs.

CONCLUSIONS

SREs are non-rare events that can occur during the treatment course for Ewing sarcoma, with an especially high incidence of malignant spinal cord compression. Patients with metastatic disease at diagnosis, especially in the bone or bone marrow, or with local progression or recurrence after definitive treatment, should be carefully monitored for the occurrence of SREs. The most effective methods to monitor the occurrence of SREs and new preventative therapies for SREs should be investigated in the future.

Pivotal role of IL-8 derived from the interaction between osteosarcoma and tumor-associated macrophages in osteosarcoma growth and metastasis via the FAK pathway

The prognosis of osteosarcoma (OS) has remained stagnant over the past two decades, requiring the exploration of new therapeutic targets. Cytokines, arising from tumor-associated macrophages (TAMs), a major component of the tumor microenvironment (TME), have garnered attention owing to their impact on tumor growth, invasion, metastasis, and resistance to chemotherapy. Nonetheless, the precise functional role of TAMs in OS progression requires further investigation. In this study, we investigated the interaction between OS and TAMs, as well as the contribution of TAM-produced cytokines to OS advancement. TAMs were observed to be more prevalent in lung metastases compared with that in primary tumors, suggesting their potential support for OS progression. To simulate the TME, OS and TAMs were co-cultured, and the cytokines resulting from this co-culture could stimulate OS proliferation, migration, and invasion. A detailed investigation of cytokines in the co-culture conditioned medium (CM) revealed a substantial increase in IL-8, establishing it as a pivotal cytokine in the process of enhancing OS proliferation, migration, and invasion through the focal adhesion kinase (FAK) pathway. In an in vivo model, co-culture CM promoted OS proliferation and lung metastasis, effects that were mitigated by anti-IL-8 antibodies. Collectively, IL-8, generated within the TME formed by OS and TAMs, accelerates OS proliferation and metastasis via the FAK pathway, thereby positioning IL-8 as a potential novel therapeutic target in OS.

Clinical characteristics and management of primary retroperitoneal sarcoma: A literature review

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.

Myxoid liposarcoma with nuclear pleomorphism: a clinicopathological and molecular study

Myxoid liposarcoma (MLS) is a common type of liposarcoma. It is characterized by variably lipogenic uniform cells in myxoid stroma with arborizing capillaries and DDIT3 fusion. Nuclear uniformity is the rule, which is maintained even in high-grade round cell examples. In this study, we conducted an in-depth investigation of four MLS tumors that demonstrated nuclear pleomorphism in three patients. These cases accounted for 2.1% of 142 patients with MLS. All patients were male aged 26, 33, and 49 years. Nuclear pleomorphism was observed in both primary and metastatic tumors in one patient, a primary tumor in one patient, and a metastatic tumor in another patient. Pleomorphism was severe in three tumors and moderate in one. Histology resembled that of dedifferentiated liposarcoma with myxoid features, pleomorphic liposarcoma with myxoid features, or myxoid pleomorphic liposarcoma in two tumors, pleomorphic sarcoma with focal cartilaginous and rhabdomyoblastic differentiation in one tumor, and epithelioid pleomorphic liposarcoma in one tumor. All tumors harbored FUS::DDIT3 fusions and immunohistochemically expressed DDIT3. All tumors had TP53 mutations, whereas previous specimens with uniform cytology from the same patients lacked TP53 mutations. One tumor showed RB1 deletion and complete loss of Rb expression, which was unclassifiable using DNA methylation-based methods. The rare occurrence of nuclear pleomorphism is underrecognized in MLS and increases the complexity to the diagnosis of liposarcoma. DDIT3 evaluation can be liberally considered in liposarcoma assessment even in the presence of nuclear pleomorphism.

Safety and Efficacy of NY-ESO-1 Antigen-Specific T-Cell Receptor Gene-Transduced T Lymphocytes in Patients with Synovial Sarcoma: A Phase I/II Clinical Trial

PURPOSE

To determine, for patients with advanced or recurrent synovial sarcoma (SS) not suitable for surgical resection and resistant to anthracycline, the safety and efficacy of the infusion of autologous T lymphocytes expressing NY-ESO-1 antigen-specific T-cell receptor (TCR) gene and siRNA to inhibit the expression of endogenous TCR (product code: TBI-1301).

PATIENTS AND METHODS

Eligible Japanese patients (HLA-A*02:01 or *02:06, NY-ESO-1-positive tumor expression) received cyclophosphamide 750 mg/m2 on days -3 and -2 (induction period) followed by a single dose of 5×109 (±30%) TBI-1301 cells as a divided infusion on days 0 and 1 (treatment period). Primary endpoints were safety-related (phase I) and efficacy-related [objective response rate (ORR) by RECIST v1.1/immune-related RECIST (irRECIST); phase II]. Safety- and efficacy-related secondary endpoints were considered in both phase I/II parts.

RESULTS

For the full analysis set (N = 8; phase I, n = 3; phase II, n = 5), the ORR was 50.0% (95% confidence interval, 15.7-84.3) with best overall partial response in four of eight patients according to RECIST v1.1/irRECIST. All patients experienced adverse events and seven of eight patients (87.5%) had adverse drug reactions, but no deaths were attributed to adverse events. Cytokine release syndrome occurred in four of eight patients (50.0%), but all cases recovered with prespecified treatment. Immune effector cell-associated neurotoxicity syndrome, replication-competent retrovirus, and lymphocyte clonality were absent.

CONCLUSIONS

Adoptive immunotherapy with TBI-1301 to selectively target NY-ESO-1-positive tumor cells appears to be a promising strategy for the treatment of advanced or recurrent SS with acceptable toxicity.

Impact of relative dose intensity of trabectedin with pegfilgrastim support: a single-centre retrospective study

Relative dose intensity (RDI) has been associated with improved survival in patients with advanced solid tumours. However, there is no evidence regarding RDI in patients under long-term treatment with trabectedin for adult advanced soft tissue sarcoma (STS). Pegfilgrastim use was associated with chemotherapy dose intensity maintenance in patients with various cancers. We retrospectively evaluated the RDI in patients with STS receiving trabectedin. The patients were grouped based on whether trabectedin administration was supported by pegfilgrastim. RDI was obtained for 114 of the 140 included patients. Chemotherapy cycles that included filgrastim were excluded. Patients treated with and without pegfilgrastim had similar RDI rates (77.1% ± 17.6% vs 78.8% ± 16.4%; P = 0.485). Moreover, we found no association between patients receiving ≥4 trabectedin cycles and the use of pegfilgrastim. These results suggested that trabectedin dose delays or reductions should be considered before administering prophylactic pegfilgrastim.

Hip Transposition Can Provide Early Walking Function After Periacetabular Tumor Resection: A Multicenter Study

BACKGROUND

Reconstruction after periacetabular bone tumor resection involves important tradeoffs; large bone grafts or endoprostheses are reported to offer fair walking function in general but can be technically demanding and carry a high risk of severe complications. Conversely, hip transposition avoids implant-related risks, but stability and functional return may be less consistent. Fewer studies are available on hip transposition, which is also appealing in more resource-constrained environments, and little is known about the time course from surgery to functional return after hip transposition.

QUESTIONS/PURPOSES

(1) What is the time course of recovery of walking function after hip transposition, especially in the first 6 months? (2) What factors are associated with a greater likelihood of early functional recovery? (3) Is early (2-month) functional recovery associated with a greater likelihood of walking ability and higher Musculoskeletal Tumor Society (MSTS) scores?

METHODS

Between 2009 and 2019, six tertiary care centers in Japan treated 48 patients with internal hemipelvectomy for malignant tumors. During that time, the preferred reconstructive approach was hip transposition, and 92% (44 of 48) of our patients were treated with this procedure. Among them, 86% (38 of 44) had follow-up of at least 6 months, had no local recurrence during that time, and were included in our retrospective study. We chose 6 months as the minimum follow-up duration because the endpoints in this study pertained to early recovery rather than reconstructive durability. Hip transposition involved moving the proximal end of the femur (femoral head, resection end of the trochanteric area, and spacers such as prostheses) upward to the underside of the resected ilium or the lateral side of the sacrum if sacroiliac joint resection was performed. The end of the proximal femur was stabilized to the remaining ilium or sacrum using polyethylene tape, polyethylene terephthalate mesh, an iliotibial tract graft, or an external fixator, according to the surgeon's preference. The median age at surgery was 46 years (range 9 to 76 years), there were 23 women and 15 men, and the median follow-up duration was 17 months (range 6 to 110 months). The postoperative time course of functional recovery was assessed with a record review, the timing of functional milestones was identified (wheelchair, walker, bilateral crutches, single crutch or cane, and walking without an aid), and the MSTS score at the final follow-up was assessed. Additionally, demographic and surgical factors were reviewed, and their association with short-term functional recovery and the final functional outcome was analyzed.

RESULTS

Patients started using a walker at median postoperative day (POD) 20 (IQR 14 to 36) and with bilateral crutches at median POD 35 (IQR 20 to 57). At POD 60, which was the approximate median date of discharge, 76% (29 of 38) of patients were able to walk using bilateral crutches (the early recovery group) and 24% (nine of 38) of patients were not able to do so (the delayed recovery group). No baseline factors were different between the two groups. The early recovery group had a higher median MSTS score than the delayed recovery group: 57% (range 17% to 90%) versus 45% (13% to 57%) (p = 0.047). Moreover, more patients acquired better function (a single crutch or cane or more) in the early recovery group, with a median of 5 months (95% CI 4 to 11) than did those in the delayed recovery group (median not reached) (p = 0.0006). The HR was 15.2 (95% CI 2.5 to 93). Forty-two percent (16 of 38) underwent additional surgery for wound management.

CONCLUSION

It took patients a fair amount of time to recover walking function after hip transposition, and patients who could not walk on bilateral crutches at POD 60 seemed less likely to regain walking function and were likely to have lower MSTS scores thereafter. Wound-related complications were frequent. This method may be a realistic alternative for younger patients who have the strength for a long rehabilitation period or those who want to minimize prosthesis-related complications. Future studies with more patients are necessary to understand the risk factors associated with delayed recovery.Level of Evidence Level III, therapeutic study.

A multicentre retrospective study on extra-thoracic solitary fibrous tumour: preoperative MRI findings predict intraoperative findings and postoperative prognosis

OBJECTIVE

The present study investigated the relationships between the preoperative and operative findings of solitary fibrous tumour (SFT) and between preoperative findings and prognosis.

METHODS

We reviewed 50 SFT patients treated at our musculoskeletal oncology hospital group. We analyzed preoperative clinical findings, particularly MRI imaging findings, and intraoperative information as well as the relationship between preoperative findings and outcomes.

RESULTS

Mean age was 48.9 years and the mean follow-up was 51.8 months. Prior to surgery, needle biopsy was performed on 27 patients and open biopsy on 14. T2-weighted images showed a high signal intensity in 24 patients and heterogeneous signal intensity in 20. Tumours had polylobular contours in 17 patients and smooth and round contours in 27. Collateral feeding vessels were detected in 22 patients. Gd-enhanced MRI was performed on 23 patients, and showed 15 with homogeneous enhancement and 8 with heterogeneous enhancement. Surgical times were significantly longer in patients with a retroperitoneal origin, a tumour of 10 cm or more, and polylobular-type tumours. Intraoperative blood loss was significantly greater in patients with a retroperitoneal origin and heterogeneous Gd-MRI-enhanced tumours. In histopathological evaluations, surgical margins were positive in 12 patients. Local recurrence was observed in one patient. Distant metastasis was noted in eight patients, four of whom had pulmonary metastases. Positive surgical margins were more common in polylobular-type tumours. Distant metastases were more likely to appear in patients with observable collateral feeding vessels and heterogeneous Gd-MRI enhancement.

CONCLUSION

The present results suggest that preoperative clinical findings in SFT patients predict longer surgical times and the risk of increased intraoperative blood loss. Moreover, the risk of a positive surgical margin and postoperative distant metastases may be predicted based on preoperative MRI.

Outcomes of Sling Procedure Using a Free Vascularized Fibular Graft After Resection of the Proximal Humerus

Background

The proximal humerus is a common site for both primary and metastatic bone tumors. Although various methods have been developed for reconstruction following resection of the proximal humerus, a consensus on which technique is best has not been established. We focused on the sling procedure using a free vascularized fibular graft (FVFG) and conducted what we believe to be the largest retrospective study of patients to undergo this surgery to date.

Methods

We retrospectively reviewed the data of 19 patients who underwent the sling procedure with use of an FVFG at our hospital between 1998 and 2022. The median age was 20 years, and the median follow-up duration was 63.1 months. Surgical data, oncological outcomes, the postoperative course, complications, and functional outcomes as measured with use of the Musculoskeletal Tumor Society (MSTS) score were thoroughly reviewed.

Results

The median operative duration was 555 minutes, and the median blood loss was 374 mL. The median length of the bone defect was 17.0 cm, and the median length of the graft was 20.0 cm. With respect to oncological outcomes, 9 patients were continuously disease-free, 9 patients had no evidence of disease, and 1 patient was alive with disease. Bone union was present in 13 of the 17 patients for whom it was evaluable. The median time to bone union was 4 months. Graft growth was observed in 2 pediatric patients. Postoperative fracture was a major complication at the recipient site. The incidence of pseudarthrosis significantly increased when the FVFG could not be inserted into the remaining humeral bone or was split in half (p = 0.002). Although a few patients demonstrated peroneal nerve palsy at the donor site, the symptom was temporary. The overall functional outcome was favorable, with an average MSTS score of 66.9%.

Conclusions

The sling procedure demonstrated a low complication rate and a favorable functional outcome overall. Therefore, we believe that this procedure is a useful reconstruction method for patients in a broad age range who have a wide defect of the proximal humerus.

Level of Evidence

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Retrospective Analysis of Retroperitoneal-Abdominal-Pelvic Ganglioneuromas: An International Study by the Transatlantic Australasian Retroperitoneal Sarcoma Working Group (TARPSWG)

OBJECTIVE

The Transatlantic Australasian Retroperitoneal Sarcoma Working Group conducted a retrospective study on the disease course and clinical management of ganglioneuromas.

BACKGROUND

Ganglioneuromas are rare tumors derived from neural crest cells. Data on these tumors remain limited to case reports and single-institution case series.

METHODS

Patients of all ages with pathologically confirmed primary retroperitoneal, intra-abdominal, and pelvic ganglioneuromas between January 1, 2000, and January 1, 2020, were included. We examined demographic, clinicopathologic, and radiologic characteristics, as well as clinical management.

RESULTS

Overall, 328 patients from 29 institutions were included. The median age at diagnosis was 37 years with 59.1% of patients being female. Symptomatic presentation comprised 40.9% of cases, and tumors were often located in the extra-adrenal retroperitoneum (67.1%). At baseline, the median maximum tumor diameter was 7.2 cm. One hundred sixteen (35.4%) patients underwent active surveillance, whereas 212 (64.6%) patients underwent resection with 74.5% of operative cases achieving an R0/R1 resection. Serial tumor evaluations showed that malignant transformation to neuroblastoma was rare (0.9%, N=3). Tumors undergoing surveillance had a median follow-up of 1.9 years, with 92.2% of ganglioneuromas stable in size. With a median follow-up of 3.0 years for resected tumors, 84.4% of patients were disease free after resections, whereas recurrences were observed in 4 (1.9%) patients.

CONCLUSIONS

Most ganglioneuromas have indolent disease courses and rarely transform to neuroblastoma. Thus, active surveillance may be appropriate for benign and asymptomatic tumors particularly when the risks of surgery outweigh the benefits. For symptomatic or growing tumors, resection may be curative.

A vessel sealing system can help reduce the risk of postoperative complications after tumour resection in the medial thigh

Aims

The risk of postoperative complications after resection of soft-tissue sarcoma in the medial thigh is higher than in other locations. This study investigated whether a vessel sealing system (VSS) could help reduce the risk of postoperative complications after wide resection of soft-tissue sarcoma in the medial thigh.

Methods

Of 285 patients who underwent wide resection for soft-tissue sarcoma between 2014 and 2021 at our institution, 78 patients with tumours in the medial thigh were extracted from our database. Information on clinicopathological characteristics, preoperative treatment, surgical treatment (use of VSS, blood loss volume, operating time), and postoperative course (complications, postoperative haemoglobin changes, total drainage volume, and drainage and hospitalization durations) were obtained from medical records. We statistically compared clinical outcomes between patients whose surgery did or did not use VSS (VSS and non-VSS groups, respectively).

Results

There were 24 patients in the VSS group and 54 in the non-VSS group. There were no significant differences between the two groups in terms of clinicopathological background. The total drainage volume in the VSS group was significantly less than that in the non-VSS group (1,176 ml vs 3,114 ml; p = 0.018). Moreover, the drainage and hospitalization durations were significantly shorter in the VSS group compared to the non-VSS group (p = 0.017 and p = 0.024, respectively).

Conclusion

Our results suggest that use of VSS can help reduce the risk of postoperative complications after wide resection of soft-tissue sarcoma in the medial thigh.

Clinical characteristics of primary cutaneous and subcutaneous Ewing sarcoma

OBJECTIVE

Given the rarity of cutaneous/subcutaneous Ewing sarcoma, their clinical characteristics remain poorly understood. In this study, we aimed to analyse the clinical characteristics of patients with cutaneous/subcutaneous Ewing sarcoma and review the treatment strategy.

METHODS

We reviewed the clinical data of 154 patients with Ewing sarcoma who were treated at our hospital between 2005 and 2019. Amongst these patients, 21 patients with cutaneous/subcutaneous Ewing sarcoma were analysed. As a basic strategy, patients with localized disease received intensive chemotherapy (vincristine-doxorubicin-cyclophosphamide/ifosfamide-etoposide), followed by definitive surgery with or without radiotherapy. In total, 15 patients underwent pre-diagnostic resection with macroscopic residue (seven patients) or non-macroscopic residue (eight patients) before intensive chemotherapy.

RESULTS

The median tumour length of the measurable lesions was 3.2 cm, and the ratio of metastasis was significantly lower than the Ewing sarcoma of other anatomical sites (10% vs. 37%, P = 0.013). Despite the pre-diagnostic resection, local recurrence after additional resection and/or adjuvant radiotherapy did not occur in any of the patients with localized disease. Overall survival was significantly higher in patients with cutaneous/subcutaneous Ewing sarcoma than in patients with Ewing sarcoma of other anatomical sites (hazard ratio = 0.33, P = 0.013). The event-free survival rate of cutaneous/subcutaneous Ewing sarcoma was also superior to that of Ewing sarcoma of other anatomical sites (hazard ratio = 0.35, P = 0.01).

CONCLUSIONS

Patients with cutaneous/subcutaneous Ewing sarcoma may have better prognosis than those with Ewing sarcoma at other anatomical sites. Although pre-diagnostic resection without appropriate investigations is not recommended, local control may be recovered by using a combination of additional resection, chemotherapy and radiotherapy.

Safety and efficacy of multiple tyrosine kinase inhibitors in pediatric/adolescent and young adult patients with relapsed or refractory osteosarcomas: A single-institution retrospective analysis

BACKGROUND

The prognosis of relapsed or refractory osteosarcoma remains poor. Recent reports have stated that molecular targeting agents, including multiple tyrosine kinase inhibitors (MTKIs), are effective against adult osteosarcoma. To determine the safety and efficacy of MTKI therapy in children, adolescents and young adults (AYAs), we conducted a retrospective study on adverse events and treatment outcomes.

METHODS

We retrospectively reviewed the medical records of patients with relapsed or refractory osteosarcoma who received MTKI therapy at the Department of Pediatric Oncology, National Cancer Center Hospital, from December 2013 to May 2021.

RESULTS

The study included 31 patients (15 males and 16 females) who received MTKIs, including sorafenib monotherapy (seven patients), sorafenib and everolimus (14 patients), and regorafenib monotherapy (10 patients). Their median age was 17 years (range: 11-22 years). The incidence of treatment-related grade 3 nonhematological adverse events was 14.3% in the sorafenib monotherapy group, 21.4% in the sorafenib with everolimus group, and 20.0% in the regorafenib monotherapy group. No grade 4 nonhematological adverse events were observed. The median progression-free survival (PFS) was 51 days in the sorafenib monotherapy group, 101 days in the sorafenib with everolimus group, and 167 days in the regorafenib monotherapy group.

CONCLUSION

The safety profile of MTKI therapies in pediatric and AYA patients was comparable to that in adult patients. MTKI therapies, particularly regorafenib, against pediatric relapsed osteosarcoma can suppress tumor growth and prolong PFS with tolerable adverse events.

Abstract 3995: Trastuzumab deruxtecan, antibody-drug conjugate targeting HER2, effectively inhibits growth of patient-derived xenograft model with CIC-rearranged sarcoma

Background: Capicua-double homeobox 4 (CIC-DUX4)-rearranged sarcomas (CDS) are extremely rare and highly aggressive sarcomas. There is no standard therapy for the patients with advanced CDS, and therapeutic development is needed. We evaluated preclinical efficacy of trastuzumab deruxtecan (T-DXd), a humanized monoclonal HER2-targeting antibody conjugated to a topoisomerase 1 inhibitor, DXd, in patient-derived xenograft (PDX) models with CDS.

Methods: Patient-derived tumor tissue was transplanted into subcutaneous around the flank of female NOG mice, which were treated with vehicle or T-DXd (3 mg/kg, intravenous, Day0) when the mean tumor volume reached 200 mm3. Tumor volume was assessed twice weekly for 3 weeks to assess the efficacy of T-DXd.

Results: This study included 3 CDS-derived PDXs. HER2 expression was low in one PDX and not expressed in two PDXs. One PDX was established from a specimen at initial diagnosis, two were established from specimens after prior-chemotherapy. T-DXd demonstrated significant tumor growth delay compared to vehicle in all PDX models investigated. One PDX with no efficacy was HER2-negative and had a treatment history of topoisomerase I inhibitor. In contrast, PDX of HER2-negative topoisomerase I inhibitor-resistant Ewing sarcoma was also administered T-DXd under the same conditions and was found to be refractory.

Conclusion: The present study showed that a therapeutic potential of T-DXd in CDS patients, including HER2-negative.

Citation Format: Yuki Kojima, Shigehiro Yagishita, Kazuki Sudo, Tatsunori Shimoi, Shintaro Iwata, Shun-ichi Watanabe, Chitose Ogawa, Akihiko Yoshida, Yasushi Yatabe, Kan Yonemori, Akinobu Hamada. Trastuzumab deruxtecan, antibody-drug conjugate targeting HER2, effectively inhibits growth of patient-derived xenograft model with CIC-rearranged sarcoma. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3995.

Mental health care use and related factors in adolescents and young adults with cancer

PURPOSE

The actual state of mental health care use and related factors in adolescent and young adult (AYA) patients with cancer is not well understood in Japan. This study aimed to (1) examine the actual state of mental health care use among AYA patients with cancer and (2) describe socio-demographic and related factors associated with mental health care use.

METHODS

We retrospectively reviewed the medical records of AYA patients with cancer aged 15-39 who first visited the National Cancer Center Hospital in Japan (NCCH) between January 2018 and December 2020. Logistic regression was used to analyze the association between social background characteristics and mental health care use. The association between the patient's course of cancer treatment and mental health care use was analyzed to help identify which patients might benefit from early mental health intervention.

RESULTS

Among 1,556 patients, 945 AYA patients with cancer were registered. The median age at the time of the study was 33 years (range, 15-39 years). The prevalence of mental health care use was 18.0% (170/945). Age 15-19 years, female gender, urogenital cancer, gynecological cancer, bone or soft tissue cancer, head and neck cancer, and stage II-IV disease were associated with mental health care use. Regarding treatment, palliative treatment, chemotherapy, and hematopoietic stem cell transplantation were associated with mental health care use.

CONCLUSION

Factors associated with mental health care use were identified. Our findings potentially contribute to psychological support interventions for AYA patients with cancer.

Predictive value of peripheral blood markers in soft tissue sarcoma patients treated with eribulin

OBJECTIVE

eribulin, an anticancer agent that inhibits microtubule growth, along with trabectedin and pazopanib, has been approved for the treatment of advanced soft tissue sarcoma (STS). However, there has been no consensus on the optimal second-line therapy among these three agents following treatment failure with doxorubicin. Recently, the effects of eribulin on the tumor microenvironment and immunity have been reported in breast cancer, and peripheral blood immune markers have also been reported to be a predictor of eribulin efficacy, though this remains unverified in STS. We aimed to evaluate the predictive value of various peripheral blood immune markers in STS patients treated with eribulin.

METHODS

we retrospectively reviewed the medical records of STS patients treated with eribulin and examined whether peripheral blood immune markers at different time points could be prognostic factors for STS patients treated with eribulin.

RESULTS

several peripheral blood immune markers were significantly associated with progression-free survival (PFS), specifically neutrophil-to-lymphocyte ratio (NLR) prestart (NLR before the initial administration of eribulin) (P = 0.019) and absolute lymphocyte count (ALC)8D (ALC on Day 8 of the first administration of eribulin) (P = 0.037). NLR prestart (P = 0.001) was significantly associated with overall survival. The combination of NLR prestart and ALC8D determined the PFS of STS patients treated with eribulin.

CONCLUSIONS

the combined indicator of low NLR prestart and high ALC8D predicted the survival of patients treated with eribulin as well as the histology of L-sarcoma. Though further validation was needed, this finding would provide valuable prognostic factor that help treatment decision in the absence of consensus on the optimal second-line therapy following doxorubicin treatment in STS patients.

Keratin-positive fibrotic extraskeletal myxoid chondrosarcoma: a close mimic of myoepithelial tumour

AIMS

Extraskeletal myxoid chondrosarcoma (EMC) is a rare form of adult sarcoma with distinct histology and NR4A3 gene fusion. Immunohistochemically, EMCs are variably positive for S100 protein and neuroendocrine markers. Unlike histologically similar soft-tissue myoepithelial tumours, keratin expression is rare. Prompted by two recent EMC cases with diffuse keratin expression, we investigated the expression of epithelial markers in a molecularly confirmed cohort of EMC and identified two additional similar cases.

METHODS AND RESULTS

Four keratin-positive EMCs occurred in one man and three women aged 46-59 years. All tumours displayed nonclassic histology with prominent stromal fibrosis, and keratin AE1/AE3 was expressed either diffusely (N = 2) or focally (N = 2). In one tumour, keratin expression was limited to the sclerotic area. All tumours coexpressed epithelial membrane antigen and two additionally expressed S100 protein or glial fibrillary acidic protein. All tumours harboured NR4A3 fusions, including TAF15::NR4A3 (N = 1) and EWSR1::NR4A3 (N = 3). Two cases were initially considered as most consistent with myoepithelial tumours based on widespread stromal fibrosis and keratin expression. DNA methylation analysis classified two tumours tested as EMCs.

CONCLUSIONS

We identified a small subset of EMCs characterised by keratin expression and prominent stromal fibrosis. This histological pattern must be recognised in the differential diagnosis of myoepithelial tumours because misclassification may lead to the erroneous prediction of tumour behaviour and may alter patient management. NR4A3 genetic analysis should be considered even in the face of keratin expression and prominent stromal fibrosis.

Dedifferentiated liposarcoma in the extremity and trunk wall: A multi-institutional study of 132 cases by the Japanese Musculoskeletal Oncology Group (JMOG)

BACKGROUND

Dedifferentiated liposarcoma occurs predominantly in the retroperitoneum. Given the paucity of cases, information on the clinical characteristics of this entity in the extremities and trunk wall is quite limited. In particular, the significance of preoperative evaluation and principles of intraoperative management of the different components, i.e., well-differentiated and dedifferentiated areas, are still to be defined.

METHODS

Clinical characteristics, treatment outcomes, and risk factors for poor oncological outcomes in cases of dedifferentiated liposarcoma in the extremity or trunk wall were analyzed by a retrospective, multicentric study.

RESULTS

A total of 132 patients were included. The mean duration from the initial presentation to dedifferentiation was 101 months in dedifferentiation-type cases. The 5-year local recurrence-free survival, metastasis-free survival, and disease-specific survival rates were 71.6%, 75.7%, and 84.7%, respectively. Among 32 patients with metastasis, 15 presented with extrapulmonary metastasis. A percentage of dedifferentiated area over 87.5%, marginal/intralesional margin, and R1/2 resection in the dedifferentiated area were independent risk factors for local recurrence. Dedifferentiated areas over 36 cm², French Federation of Cancer Centers Sarcoma Group grade III, and intralesional or marginal resection were independent risk factors for metastasis. A dedifferentiated area over 77 cm² and lung metastasis were independent risk factors for disease-specific mortality.

CONCLUSIONS

The typical clinical characteristics of dedifferentiated liposarcoma in the extremity and trunk wall were reconfirmed in the largest cohort ever. The evaluation of the dedifferentiated area in terms of grade, extension, and pathological margin, together with securing adequate surgical margins, was critical in the management of this entity.

Japanese Orthopaedic Association (JOA) clinical practice guidelines on the management of soft tissue tumors 2020 - Secondary publication

BACKGROUND

These clinical practice guidelines are intended to provide recommendations based on the best evidence obtained to date on key issues in clinical practice to improve the prognosis, diagnostic and therapeutic processes for patients with soft tissue tumors.

METHODS

The Guidelines Development Committee and Systematic Review Committee were composed of a multidisciplinary team of specialists who play an important role in soft tissue tumor care. Clinical questions (CQs) were determined by choosing key decision-making points based on Algorithms for the diagnosis and treatment of soft tissue tumors. The guidelines were developed according to the "Medical Information Network Distribution Service (Minds) Handbook for Clinical Practice Guideline Development 2014" and "Minds Manual for Clinical Practice Guideline Development 2017." Recommendation strength was rated on two levels and the strength of evidence was rated on four levels. The recommendations were decided based on agreement by 70% or more voters.

RESULTS

Twenty-two CQs were chosen by the Guidelines Development Committee. The Systematic Review Committee reviewed the evidence concerning each CQ, a clinical value judgment was added by experts, and the text of each recommendation was determined.

CONCLUSION

We established 22 CQs and recommendations for key decision-making points in the diagnosis and treatment of soft tissue tumors according to the Minds Clinical Practice Guideline development methods. We hope that these guidelines will assist the decision-making of all medical staff engaged in the treatment and diagnosis of soft tissue tumors, and eventually lead to improved soft tissue tumor care in the country.

Clinical features and treatment outcomes of dedifferentiated and grade 3 chondrosarcoma: A multi-institutional study

Chondrosarcoma is the second most common primary malignant bone tumor. In this multicenter study, we sought to evaluate the (i) disease-specific survival (DSS) and disease-free survival (DFS), and (ii) prognostic factors in patients with dedifferentiated chondrosarcoma (DDCS) and grade 3 chondrosarcoma (G3CS) in Japan. We retrospectively investigated the treatment outcomes and prognostic factors in 62 patients with DDCS and 19 patients with G3CS at 15 institutions participating in the Japanese Musculoskeletal Oncology Group. We also clarified significant clinico-pathological factors for oncological outcomes. In surgery for primary lesions aimed at cure, a histologically negative margin (R0) was obtained in 93% (14/15) of patients with G3CS and 100% (49/49) of patients with DDCS. The 5-year DSS was 18.5% in patients with DDCS and 41.7% in patients with G3CS (P = 0.13). Local control was obtained in 80% (12/15) and 79.6% (39/49) of patients with G3CS and DDCS in the primary lesion after surgery with a wide surgical margin, respectively. In multivariate analysis, stage and no treatment/palliative treatment for the primary lesion were independent prognostic factors for DSS of DDCS, age and no treatment/palliative treatment for DSS of G3CS. The 5-year DFS rate was 22.8% in 26 patients with DDCS who did not receive adjuvant chemotherapy, and 21.4% in 14 patients who received adjuvant chemotherapy. The prognosis of DDCS remains poor, although R0 resection was performed in most cases. Effective and/or intensive chemotherapeutic regimens or agents should be considered or developed for patients with high-grade chondrosarcoma, particularly for those with DDCS.

Poor Treatment Outcomes with Second-Line Chemotherapy in Advanced Synovial Sarcoma

Introduction: Synovial sarcoma predominantly affects adolescents and young adults. Doxorubicin with or without ifosfamide therapy is the standard first-line treatment for unresectable or metastatic synovial sarcoma. However, there is no standard second-line chemotherapy regimen. The purpose of the current study was to evaluate the outcomes of second-line chemotherapy for patients with synovial sarcoma. Methods: We retrospectively evaluated the outcomes of 61 patients with unresectable or metastatic synovial sarcoma who had received first-line chemotherapy at our institution between 1997 and 2017. Patients who received second-line chemotherapy were included in the analysis. Outcomes of the chemotherapy were evaluated. Results: Among the 61 patients treated with first-line chemotherapy, we identified 32 patients who received second-line chemotherapy. Most patients (62.5%) were under 40 years of age. Regarding second-line chemotherapy regimens, 6 (18.8%) patients were treated with doxorubicin with/without ifosfamide, 6 (18.8%) with ifosfamide and etoposide, 4 (12.5%) with docetaxel and gemcitabine, 5 (15.6%) with pazopanib, 2 (6.2%) with trabectedin, and 1 (3.1%) with eribulin. The overall response rate according to the Response Evaluation Criteria in Solid Tumors for all patients was 9.4%. Eleven patients (34.3%) achieved disease-control for > 6 months. The median follow-up duration was 15.2 months. The 1-year progression-free and overall survival rates were 33.1% and 67.1%, respectively. Conclusion: Our exploratory study revealed that the response rate of second-line chemotherapy regimens for patients with synovial sarcoma was 9.4%. Therefore, there is an urgent need to develop more active therapeutic regimens for synovial sarcomas.

Establishment and characterization of NCC-DDLPS5-C1: a novel patient-derived cell line of dedifferentiated liposarcoma

Dedifferentiated liposarcoma (DDLPS) is a highly aggressive subtype of liposarcoma that is morphologically defined as a transition from a well-differentiated lipomatous component to a non-lipogenic one. Curative therapy for DDLPS is complete resection, and the benefits of current systemic chemotherapy remain marginal. Although DDLPS is molecularly characterized by co-amplification of MDM2 and CDK4 (12q14-15) and detailed genomic analyses have been conducted by multiple research groups, the effects of molecular targeted drugs are marginal, and novel therapeutic modalities are required. Although patient-derived cell lines are pivotal for cancer research, no DDLPS cell lines are currently available from public cell repositories. Accordingly, in this study, we established a novel DDLPS cell line, NCC-DDLPS5-C1, using surgically resected tumor tissues from a patient with DDLPS. NCC-DDLPS5-C1 cells exhibited typical gene amplification, overexpression of MDM2 and CDK4, and other DNA copy number alterations. The NCC-DDLPS5-C1 cells were capable of rapid cell proliferation, aggressive invasion, and spheroid formation, but not tumor formation in mice. We reported the utility of NCC-DDLPS5-C1 cells for a drug-response assay to detect anticancer drugs that significantly attenuated cell proliferation. Thus, we concluded that the NCC-DDLPS5-C1 cell line could be a useful resource for the study of DDLPS. Considering the diversity of disease in terms of clinical outcomes, continuous efforts are required to develop more patient-derived cancer models with different clinical and pathological backgrounds.

Utility of a multidisciplinary team approach with transanal total mesorectal excision for resection of a large pelvic solitary fibrous tumor

Introduction

Solitary fibrous tumors require complete surgical resection to avoid recurrence. Large solitary fibrous pelvic tumors are difficult to resect completely with conventional surgical methods. We herein report a case in which a joint surgical approach was required for resection due to the location and size of tumor.

Case presentation

A 45‐year‐old man had a large solitary fibrous tumor in the pelvis, which extended into the left obturator foramen. The patient underwent tumor resection with vesico‐prostatectomy, transanal total mesorectal excision, and opening of the foramen obturatum. The tumor was grossly resected completely. No recurrence was noted nine months after surgery.

Conclusion

A multidisciplinary team approach with transanal total mesorectal excision may provide complete resect of large pelvic solitary fibrous tumors.

Marginal resection for patients with atypical lipomatous tumours of the extremities and trunk wall: a systematic review and meta-analysis

BACKGROUND

This systematic review assessed and compared the efficacy of marginal resection to wide resection in patients with atypical lipomatous tumours (ALT) by evaluating the local recurrence rates, overall survival and adverse event rates.

METHODS

We evaluated studies published between 1 January 1990 and 31 January 2019. The risks of bias in the selected studies were analyzed using the Cochrane Collaboration Risk of Bias Tool. The quality of the evidence was evaluated using the Grading of Recommendations, Assessment, Development and Evaluation approach.

RESULTS

Three case-control studies and three case series studies were identified. A meta-analysis was performed of six studies to evaluate the local recurrence rate after resection. Comparison of marginal and wide resections showed that the local recurrence rate was not significantly higher in the marginal resection group (14.2 and 1.4%, odds ratio: 2.88, 95% confidence interval 0.99-8.33, P = 0.05). We observed no difference in overall survival. In one study, the rates of adverse events were 14.7% in the marginal resection group and 45.4% in the wide treatment group (odds ratio, 0.32; 95% confidence interval 0.11-80.91, P < 0.05).

CONCLUSIONS

In our analyses, five of six studies reported no recurrence for wide resection, compared to three to seven recurrences in the marginal resection group. One study reported only one case of recurrence for wide resection. Because ALT has a relatively good prognosis, the use of marginal resection is acceptable to preserve musculoskeletal function.

Immuno-transcriptomic profiling of extracranial pediatric solid malignancies

We perform an immunogenomics analysis utilizing whole-transcriptome sequencing of 657 pediatric extracranial solid cancer samples representing 14 diagnoses, and additionally utilize transcriptomes of 131 pediatric cancer cell lines and 147 normal tissue samples for comparison. We describe patterns of infiltrating immune cells, T cell receptor (TCR) clonal expansion, and translationally relevant immune checkpoints. We find that tumor-infiltrating lymphocytes and TCR counts vary widely across cancer types and within each diagnosis, and notably are significantly predictive of survival in osteosarcoma patients. We identify potential cancer-specific immunotherapeutic targets for adoptive cell therapies including cell-surface proteins, tumor germline antigens, and lineage-specific transcription factors. Using an orthogonal immunopeptidomics approach, we find several potential immunotherapeutic targets in osteosarcoma and Ewing sarcoma and validated PRAME as a bona fide multi-pediatric cancer target. Importantly, this work provides a critical framework for immune targeting of extracranial solid tumors using parallel immuno-transcriptomic and -peptidomic approaches.

Kdm5a promotes B cell activation in systemic lupus erythematosus via downregulation of A20 by histone modification

Systemic lupus erythematosus (SLE) is a classic autoimmune connective tissue disease, which leads to multiple organ system injury. Tumor necrosis factor-induced protein 3 (TNFAIP3), generally called A20, has been documented to go together with the development of SLE. However, the role and mechanism of A20 in the progression of SLE are still unrevealed. In our study, A20 was downregulated in B cells from SLE patients and B cell responsiveness was significantly elevated in SLE patients. Overexpression of A20 restrained the proliferation and induced the apoptosis of B cells. Additionally, trimethylation of histone H3 Lysine 4 (H3K4me3) was decreased in the A20 promoter of SLE B cells. Lysine demethylase 5 A (Kdm5a) was significantly increased in B cells from SLE patients and negatively correlated with A20 expression. Further, Kdm5a knockdown increased the H3K4me3 level and A20 expression. More importantly, Kdm5a promoted the proliferation and inhibited the apoptosis of B cells in SLE via downregulation of A20. In general, Kdm5a promoted the proliferation and inhibited the apoptosis of B cells in SLE via downregulation of A20 by decreasing H3K4me3 enrichment level in the A20 promoter, suggesting a novel mechanism underlying SLE progression, and providing a promising therapeutic target for SLE. AVAILABILITY OF DATA AND MATERIALS: All data generated or analyzed during this study are included in this published article and its additional files.

Establishment and characterization of NCC-LGFMS1-C1: a novel patient-derived cell line of low-grade fibromyxoid sarcoma

Low-grade fibromyxoid sarcoma (LGFMS) is a rare soft-tissue sarcoma genetically characterized by the presence of the FUS-CREB3L2 gene fusion. While LGFMS exhibits indolent features during its early stages, the rates of recurrence, metastasis, and death from the disease are high. Presently, the role of FUS-CREB3L2 gene fusions in the unique features of LGFMS is not clear, and there is no modality to improve the clinical outcomes of patients with LGFMS; thus, extensive studies on LGFMS are required. Patient-derived cancer cell lines are critical tools for cancer research. However, no cell line has been established for LGFMS. Here, we aimed to develop a novel cell line for LGFMS and successfully established it using surgically resected tumor tissues. The cells, named NCC-LGFMS1-C1, possessed the same fusion genes as their original tumor and visible copy number variations. The cells had a fibroblastic appearance, formed spheroids when they were seeded in a low-attachment dish, and exhibited constant growth and invasion. Additionally, we demonstrated the feasibility of high-throughput drug screening using these cells. In conclusion, the NCC-LGFMS1-C1 cell line is a useful tool for studying LGFMS.

Benefit of surgical resection of distant metastasis in soft tissue sarcoma: a systematic review

OBJECTIVE

The aim of this systematic review was to evaluate the efficacy of metastasectomy for patients with advanced soft tissue sarcoma and to develop a recommendation outlining clinical guidelines for soft tissue sarcoma.

METHODS

We searched the pertinent literature from January 1985 to December 2017. Two reviewers evaluated and screened the literature independently for eligibility and extracted data. We evaluated the quality of body of evidence and made a recommendation according to the Grading of Recommendations Development and Evaluation methodology.

RESULTS

Among 244 identified studies, only 10 were finally included in this review and no randomized controlled trial reports were present. The median survival period after metastasectomy ranged from 9.6 to 39.6 months, and the 5-year survival rate ranged from 8 to 52%. The complication rate ranged from 7.3 to 25%, and the perioperative mortality rate was 0-1%. The guidelines committee proposed 'Metastasectomy can be offered for malignant soft tissue tumours with distant metastases'. This recommendation gained 100% consensus among the members of the guidelines group.

CONCLUSIONS

Although the level of evidence is very low, many retrospective studies support a clinical advantage for metastasectomy, and surgical indications should be carefully considered for patients with metastasis from soft tissue sarcoma. Metastasectomy is an option for patients with metastasis and should be done only if it can be performed safely and if potential advantages outweigh disadvantages.

Efficacy and safety of TAS-115, a novel oral multi-kinase inhibitor, in osteosarcoma: an expansion cohort of a phase I study

Background osteosarcoma is a rare, primary malignant bone tumour with limited available treatments for advanced or recurrent disease, resulting in a poor prognosis for patients. TAS-115 is a novel tyrosine kinase inhibitor under investigation in a phase I study in patients with solid tumours. We report data of osteosarcoma patients in the expansion cohort of this ongoing study. Patients and methods an analysis of this multicentre, open-label study was performed 6 months after the final patient was enrolled, and included patients aged ≥15 years, with unresectable or recurrent osteosarcoma, and who had refractory to standard therapy or for whom no standard therapy was available. TAS-115 650 mg/day was orally administered in a 5 days on/2 days off schedule. Results a total of 20 patients with osteosarcoma were enrolled. The most common adverse drug reactions (ADRs) were neutrophil count decreased (75%), aspartate aminotransferase increased (50%), and platelet count decreased (50%); 85% of patients had grade ≥ 3 ADRs. Long-term disease control (>1 year) with TAS-115 was achieved in three patients. The best overall response was stable disease (50%); no patient achieved a complete or partial response. Median progression-free survival was 3 months; 4-month and 12-month progression-free rates were 42% and 31%, respectively. Conclusion the safety and tolerability of TAS-115 and long-term disease stability for patients with unresectable or recurrent osteosarcoma were confirmed in this study, suggesting that TAS-115 is a promising novel therapy for advanced osteosarcoma patients. Trial registration number: JapicCTI-132333 (registered on November 8, 2013).

Is perioperative chemotherapy recommended in childhood and adolescent patients with synovial sarcoma? A systematic review

OBJECTIVE

Synovial sarcoma is the most common soft tissue sarcomas among childhood and adolescents, accounting for 8-10% of all soft tissue sarcoma. Synovial sarcoma is considered a relatively chemosensitive tumor compared with other soft tissue sarcomas. However, the role of perioperative chemotherapy in synovial sarcoma remains controversial. The purpose of this systematic review is to evaluate the role of perioperative chemotherapy in childhood and adolescent patients with synovial sarcoma.

METHODS

We evaluated studies published between 1 January 1990 and 31 December 2017. The following databases were searched: MEDLINE, Cochrane database (via PubMed) and Ichushi (in Japanese).

RESULTS

The search yielded 216 articles in English and Japanese. After the initial screening, based on the title and abstract, 160 articles were excluded. As a second screening, we then assessed the full text of the remaining 56 articles for eligibility. Finally, 10 articles were included in the systematic review. Surgical resection with R0 margin alone was recommended because of the excellent results of two prospective studies. Meta-analysis was performed using data from two retrospective studies of 261 patients. Perioperative chemotherapy did not have a significant effect on survival and event-free survival.

CONCLUSIONS

We weakly do not recommend perioperative chemotherapy in patients with non-metastatic synovial sarcoma ≤ 5 cm when R0 resection is acquired. There was no consensus concerning the role of perioperative chemotherapy in patients with synovial sarcoma > 5 cm or those with ≤5 cm who undergo R1 or R2 resection.

Prognostic factors and impact of surgery in patients with metastatic soft tissue sarcoma at diagnosis: A population-based cohort study

BACKGROUND

Approximately 10% of the patients with soft tissue sarcoma show metastasis at initial diagnosis, and hence, poorer prognosis. However, the prognostic factors and whether definitive surgery for the primary lesion improves overall survival, especially when complete resection of metastasis is difficult, remain unclear.

METHODS

This retrospective analysis was based on the Bone and Soft Tissue Tumor Registry in Japan. Patients with soft tissue sarcoma having metastasis at diagnosis were enrolled, excluding those with Ewing's sarcoma, rhabdomyosarcoma and several other sarcomas with unique behavior and treatment strategies. Overall survival was estimated using the Kaplan-Meier method and compared among the common histologic subtypes. Multivariate analysis with the Cox regression model was used to identify the prognostic factors.

RESULTS

In total, 1184 patients were included, with a median follow-up duration of 10 months (range: 1-83). The median overall survival was 21 months (95% confidence interval: 18.2-23.8). The multivariate analyses indicated that tumor size, grade and histologic subtypes significantly correlated with overall survival. Moreover, surgery for the primary lesion, in addition to surgery for metastases and chemotherapy, showed significant association with better survival.

CONCLUSIONS

The prognostic factors in patients with metastatic soft tissue sarcoma at diagnosis are generally similar to those in patients with localized disease. The overall survival in patients differed significantly according to histologic subtype. Surgical resection of primary lesions, especially those with a wide margin, may be an independent prognostic factor. Further studies are needed identify which subgroup of patients would benefit the most from primary lesion surgery.

CDK4 overexpression is a predictive biomarker for resistance to conventional chemotherapy in patients with osteosarcoma

Osteosarcoma (OS) is the most common malignant bone tumor, and its sensitivity to preoperative chemotherapy is a significant prognostic factor. The present study aimed to identify potential genomic markers for the prediction of chemosensitivity in patients with OS using a genomic approach. A total of 50 pediatric and adolescent patients diagnosed with high‑grade OS were selected. Each pre‑therapeutic biopsy sample was subjected to comparative genomic hybridization array analysis and targeted exome sequencing. Although no recurrent gene mutation was observed in chemoresistant tumors, copy number analysis detected recurrent gain of chromosome 12q14.1, which was significantly more frequent (5/21; 24%) in the poor responder cohort than in the good responder cohort (0/29; 0%; P<0.01). Subsequent expression analysis revealed that CDK4 was the only gene in the 12q14.1 gained region with an expression level that was positively associated with copy number gains. In order to elucidate the effect of CDK4 on drug sensitivity, CDK4‑overexpressing OS cell lines were treated with cisplatin (CDDP); significant attenuation of CDDP sensitivity, demonstrated by increased cell viability and decreased expression of cleaved caspase‑9, was induced by enforced expression of CDK4. In addition, treatment with CDK4/6 inhibitor palbociclib in CDK4‑overexpressing U2OS cells facilitated apoptosis and a significant decrease in cell viability in a dose‑dependent manner. In conclusion, the results of the present study showed that higher expression and amplification of CDK4 in tumors is a predictive biomarker for resistance to conventional chemotherapy in patients with OS and that palbociclib is a promising drug for this therapeutically challenging cohort.

A randomized phase II trial of second-line treatment for advanced soft tissue sarcoma comparing trabectedin, eribulin and pazopanib (2ND-STEP, JCOG1802)

TPS11580

Background: Soft tissue sarcomas (STS) are a rare type of malignancy, which comprises of a variety of histologies. Chemotherapy is the standard treatment for patients with advanced STS. Doxorubicin alone or in combination with ifosfamide is widely accepted as the first-line chemotherapy for advanced STS. While a combination with gemcitabine and docetaxel is regarded as a standard regimen of the second-line chemotherapy after failure of doxorubicin-based first-line regimen, the efficacy is not sufficient. Trabectedin, eribulin, and pazopanib are the candidates of the second-line chemotherapy for advanced STS, although there is no clear evidence showing which is better among those agents. The purpose of this clinical trial conducted by Bone and Soft Tissue Tumor Study Group of Japan Clinical Oncology Group (JCOG) is to determine the most promising regimen among trabectedin, eribulin and pazopanib as the test arm regimen in the future phase III trial of the second-line treatment for patients with advanced STS. Methods: The study, JCOG1802, is a multicenter, selection design, randomized phase II trial comparing trabectedin (1.2 mg/m2 IV, every 3 weeks), eribulin (1.4 mg/m2 IV, days 1 and 8, every 3 weeks) and pazopanib (800 mg PO, everyday) for patients with unresectable or metastatic STS refractory to doxorubicin-based first-line chemotherapy. Eligibility criteria include 16 year-old or older, unresectable and/or metastatic STS, an exacerbation within 6 months prior to registration, histological diagnosis of STS other than Ewing sarcoma, well-differentiated liposarcoma and myxoid liposarcoma, a history of chemotherapy for STS other than doxorubicin-based regimen, ECOG (Eastern Cooperative Oncology Group) performance status 0 to 2, and sufficient organ function. Primary endpoint is progression-free survival (PFS), and secondary endpoints include overall survival, disease-control rate, response rate, and adverse events. To select the most promising regimen in median PFS (3 months in the worst regimen and 4 months in the best regimen) with a probability of at least 80%, a total of 120 patients will be enrolled from 37 institutions in Japan. After JCOG1802, a subsequent phase III trial comparing the winner of this study and a combination of gemcitabine and docetaxel will be planned. The study was activated at December 5, 2019 and 22 of planned 120 patients have been enrolled as of February 15, 2021. Clinical trial information: jRCTs031190152.

Establishment and characterization of NCC-MFS3-C1: a novel patient-derived cell line of myxofibrosarcoma

Myxofibrosarcoma (MFS) is one of the most aggressive sarcomas with highly complex karyotypes and genomic profiles. Although a complete resection is required in the treatment of MFS, it is often not achieved due to its strong invasive nature. Additionally, MFS is refractory to conventional chemotherapy, leading to poor prognosis. Therefore, it is necessary to develop novel treatment modalities for MFS. Patient-derived cell lines are important tools in basic research and preclinical studies. However, only 10 MFS cell lines have been reported to date. Furthermore, among these cell lines, merely two MFS cell lines are publicly available. Hence, we established a novel MFS cell line named NCC-MFS3-C1, using a surgically resected tumor specimen from a patient with MFS. NCC-MFS3-C1 cells had copy number alterations corresponding to the original tumor. NCC-MFS3-C1 cells demonstrate constant proliferation, spheroid formation, and aggressive invasion. In drug screening tests, the proteasome inhibitor bortezomib and the histone deacetylase inhibitor romidepsin demonstrated significant antiproliferative effects on NCC-MFS3-C1 cells. Thus, the NCC-MFS3-C1 cell line is a useful tool in both basic and preclinical studies for MFS.

Liquid Biopsy Targeting Monocarboxylate Transporter 1 on the Surface Membrane of Tumor-Derived Extracellular Vesicles from Synovial Sarcoma

The lack of noninvasive biomarkers that can be used for tumor monitoring is a major problem for soft-tissue sarcomas. Here we describe a sensitive analytical technique for tumor monitoring by detecting circulating extracellular vesicles (EVs) of patients with synovial sarcoma (SS). The proteomic analysis of purified EVs from SYO-1, HS-SY-II, and YaFuSS identified 199 common proteins. DAVID GO analysis identified monocarboxylate transporter 1 (MCT1) as a surface marker of SS-derived EVs, which was also highly expressed in SS patient-derived EVs compared with healthy individuals. MCT1+CD9+ EVs were also detected from SS-bearing mice and their expression levels were significantly correlated with tumor volume (p = 0.003). Furthermore, serum levels of MCT1+CD9+ EVs reflected tumor burden in SS patients. Immunohistochemistry revealed that MCT1 was positive in 96.7% of SS specimens and its expression on the cytoplasm/plasma membrane was significantly associated with worse overall survival (p = 0.002). Silencing of MCT1 reduced the cellular viability, and migration and invasion capability of SS cells. This work describes a new liquid biopsy technique to sensitively monitor SS using circulating MCT1+CD9+ EVs and indicates the therapeutic potential of MCT1 in SS.

Surgical resection of the primary lesion for osteosarcoma patients with metastasis at initial diagnosis

BACKGROUND

Approximately 10-20% of osteosarcoma patients present with metastasis on diagnosis. Completely resecting the lesion is associated with better prognosis. However, evidence regarding optimal surgical strategies for patients with unresectable metastasis is limited.

METHODS

This retrospective analysis was based on the Japanese Nationwide Bone and Soft Tissue Tumor registry. In total, 335 patients diagnosed with osteosarcoma with metastasis were included. Factors affecting overall survival were identified using multivariate analysis. Kaplan-Meier method was used to compare the overall survival by the status of surgical intervention. Two hundred and four patients who did not undergo surgery for metastasis were divided into two groups, depending on whether they underwent surgery for the primary lesion. The background differences between these two groups were adjusted with propensity score matching, with 43 patients per group. The overall survival was calculated using the Kaplan-Meier method and compared with a log-rank test.

RESULTS

Factors positively impacting overall survival were age <40, female sex, extremity origin, surgery for the primary lesions, surgery for metastasis and radiotherapy without surgery. For patients with unresectable metastasis, after propensity score matching, the survival rate was higher in the group that underwent primary lesion surgery than the group without surgery. Their median survival was 19 (95% confidence interval: 11.7-26.3) and 11 months (95% confidence interval: 4.5-17.5) (P = 0.02), respectively.

CONCLUSIONS

Surgical resection of the primary osteosarcoma lesion did not worsen prognosis, even in patients with unresectable metastasis. Further study is needed to identify which patient group will benefit from primary lesion resection.

Systemic therapies in advanced epithelioid haemangioendothelioma: A retrospective international case series from the World Sarcoma Network and a review of literature

Background

This observational, retrospective effort across Europe, US, Australia, and Asia aimed to assess the activity of systemic therapies in EHE, an ultra‐rare sarcoma, marked by WWTR1‐CAMTA1 or YAP1‐TFE3 fusions.

Methods

Twenty sarcoma reference centres contributed data. Patients with advanced EHE diagnosed from 2000 onwards and treated with systemic therapies, were selected. Local pathologic review and molecular confirmation were required. Radiological response was retrospectively assessed by local investigators according to RECIST. Progression free survival (PFS) and overall survival (OS) were estimated by Kaplan‐Meier method.

Results

Overall, 73 patients were included; 21 had more than one treatment. Thirty‐three patients received anthracyclines regimens, achieving 1 (3%) partial response (PR), 25 (76%) stable disease (SD), 7 (21%) progressive disease (PD). The median (m‐) PFS and m‐OS were 5.5 and 14.3 months respectively. Eleven patients received paclitaxel, achieving 1 (9%) PR, 6 (55%) SD, 4 (36%) PD. The m‐PFS and m‐OS were 2.9 and 18.6 months, respectively. Twelve patients received pazopanib, achieving 3 (25%) SD, 9 (75%) PD. The m‐PFS and m‐OS were.2.9 and 8.5 months, respectively. Fifteen patients received INF‐α 2b, achieving 1 (7%) PR, 11 (73%) SD, 3 (20%) PD. The m‐PFS and m‐OS were 8.9 months and 64.3, respectively. Among 27 patients treated with other regimens, 1 PR (ifosfamide) and 9 SD (5 gemcitabine +docetaxel, 2 oral cyclophosphamide, 2 others) were reported.

Conclusion

Systemic therapies available for advanced sarcomas have limited activity in EHE. The identification of new active compounds, especially for rapidly progressive cases, is acutely needed.

Establishment and characterization of NCC-SS4-C1: a novel patient-derived cell line of synovial sarcoma

Synovial sarcoma (SS) is defined as a monomorphic blue spindle cell sarcoma showing variable epithelial differentiation, and is characterized by a specific fusion gene, SS18-SSX. Although SS is rare, it accounts for approximately 8% of all soft tissue sarcomas, which occupies a significant proportion of soft tissue tumors. The prognosis of SS is unfavorable, with 5-year survival rate of 50-60%, and only a few anti-cancer agents are recommended for its treatment. Thus, we need to urgently establish novel treatment methods. Patient-derived cell lines are essential tools in basic research and pre-clinical studies. However, there are only 4 publicly available SS cell lines. Therefore, we established a novel SS cell line, NCC-SS4-C1, using surgically resected tumor tissues of a patient with SS. The cell line maintained the characteristic fusion gene, SS18-SSX1, and copy number alteration, in concordance with the original tumor. The cells also exhibited moderate cell proliferation, invasion ability, and spheroid formation ability. Moreover, a drug-screening test using 4 SS cell lines, including NCC-SS4-C1, demonstrated the significant anti-proliferative effects of ALK and HDAC inhibitors. Thus, we concluded that the NCC-SS4-C1 cell line is a useful tool for basic and pre-clinical studies of SS.

Comprehensive molecular and clinicopathological profiling of desmoid tumours

Previous studies have not clearly identified a prognostic factor for desmoid tumours (DT). Whole-exome sequencing (WES) and/or RNA sequencing (RNA-seq) were performed in 64 cases of DT to investigate the molecular profiles in combination with the clinicopathological characteristics. CTNNB1 mutations with specific hotspots were identified in 56 cases (87.5%). A copy number loss in chromosome 6 (chr6) was identified in 14 cases (21.9%). Clustering based on the mRNA expression profiles was predictive of the patients' prognoses. The risk score generated by the expression of a three-gene set (IFI6, LGMN, and CKLF) was a strong prognostic marker for recurrence-free survival (RFS) in our cohort. In risk groups stratified by the expression of IFI6, the hazard ratio for recurrence-free survival in the high-risk group relative to the low-risk group was 12.12 (95% confidence interval: 1.56-94.2; p = 8.0 × 10⁶). In conclusion, CTNNB1 mutations and a chr6 copy number loss are likely the causative mutations underlying the tumorigenesis of DT while the gene expression profiles may help to differentiate patients who would be good candidates for wait-and-see management and those who might benefit from additional systemic or radiation therapies.

Symptomatic Venous Thromboembolism in Patients with Malignant Bone and Soft Tissue Tumors: A Prospective Multicenter Cohort Study

BACKGROUND

A prospective cohort study was conducted to determine the incidence and risk factors of symptomatic venous thromboembolism (sVTE) during the perioperative period in patients with malignant bone and soft tissue tumors.

METHODS

Patients with newly diagnosed primary malignant bone and soft tissue tumors for whom definitive surgery was planned were consecutively registered among 27 tertiary hospitals specializing in musculoskeletal oncology. Clinicopathological information on each patient was collected prospectively, and careful follow-up was conducted for 6 months after surgery. The study endpoint was the occurrence of sVTE, including deep vein thrombosis (DVT) and pulmonary embolism (PE).

RESULTS

Eleven of 929 patients developed sVTE, including 8 patients with DVT, 2 with PE, and 1 with both, making the incidence of sVTE 1.18%. The median time until the development of sVTE after tumor resection was 11 days, ranging from - 7 to 95 days. Multiple logistic regression analyses revealed that ischemic heart disease as a comorbidity, maximum tumor diameter exceeding 8 cm, and elevated preoperative platelet count were independent risk factors for sVTE.

CONCLUSIONS

The incidence of sVTE in this series of patients with bone and soft tissue sarcomas was 1.18%, which was relatively lower than in previous retrospective studies. We identified the risk factors for sVTE specific to patients with malignant bone and soft tissue tumors, and these included ischemic heart disease, tumor size, and elevation of the preoperative platelet count.

Prognostic factors of metastatic myxoid liposarcoma

BACKGROUND

Myxoid liposarcoma (MLS) has the tendency to metastasize extrapulmonary. Although prognostic factors at the initial diagnosis of MLS have been reported, those at diagnosis of metastasis remain unclear. The purpose of this study was to investigate the prognostic factors for disease-specific survival at the initial diagnosis of metastasis.

METHODS

This retrospective observational study was conducted at three cancer centers and two university hospitals in Japan. Of 274 MLS patients pathologically diagnosed between 2001 and 2015, 48 metastatic patients were examined.

RESULTS

Lung metastases were detected in nine patients (18.8%) and extrapulmonary metastases in 45 (93.8%). Interval from primary diagnosis to the first metastasis was significantly shorter in patients with lung metastases than without (p = 0.007). Median disease-specific survival after diagnosis of metastases was 52.5 months in all patients. In multivariable analysis, liver metastasis (hazard ratio (HR), 2.71 [95% confidence interval (CI), 1.00-7.09]) and no evidence of disease (NED) achieved by radical treatment (resection with or without radiation therapy, or radiation therapy ≥60 Gy) or semi-radical (radiation therapy ≥40 Gy) treatment were significantly related to survival (HR, 0.36; 95%CI [0.13-0.95]). The number of metastases (odds ratio (OR), 0.44; 95%CI [0.25-0.78]) and abdominal/retroperitoneal metastases (OR, 0.09; 95%CI [0.008-0.95]) were the significant inhibitory factors of achieving NED.

CONCLUSIONS

This is the first study to statistically demonstrate the importance of achieving NED with surgical resection or radiation therapy for longer survival in metastatic MLS patients. As number of metastases was a significant factor for achieving NED, early detection of metastases might be important.

Abstract LB-307: Translational and mechanistic implications of osteosarcoma genomics: A TARGET report

Osteosarcoma (OS) is the most common malignant bone tumor of children and young adults. Although the optimization of combination chemotherapy has led to significantly improved prognosis, survival remains poor for patients with recurrent tumor or metastatic disease at diagnosis. The international TARGET (Therapeutically Applicable Research to Generate Effective Therapy) OS project team collected 285 clinically annotated samples (age &lt;40 years) for integrative genomics analyses. Eighty-nine cases, the discovery set, were characterized with paired tumor and normal DNA sequencing as well as profiling of transcriptomes, DNA methylation, and miRNA. An additional 196 validation cases were used for copy number analysis and targeted DNA sequencing guided by results from the discovery set. The most frequent recurrent somatic mutations cause loss of function in the tumor suppressors TP53, RB1, CDKN2A, PTEN, and NF1 as well as the chromatin remodeler ATRX. Structural rearrangements are an important mechanism of inactivation for all of these genes. In the discovery set, every case carried at least one mutation of a cell cycle regulator, with TP53 somatically altered in 87/89 cases. Analysis of TP53 mutations suggests that these are often truncal. OS genomes are strikingly complex and contain copy number aberrations (CNA) arising from aneuploidy and extensive structural rearrangements. Transcriptome analysis revealed profound remodeling of gene expression with statistically significant correlation of CNA and gene expression of 3340 genes (FDR&lt;0.001). Regions of high copy number amplification include known therapeutically relevant cancer drivers (e.g. PDGFRA, MYC, CDK4, MDM2, IGF1R, and CCNE1). In contrast, activating mutations of signal transduction genes were rare. With few exceptions (e.g. MYC amplification), mutations or CNA of individual genes were not predictive of outcome. The pattern of significant co-occurrence or mutual exclusion of frequent mutations and amplifications allowed partitioning of 240 cases into four distinct genomic groups. One of these, characterized by relatively simple genomes lacking high copy number amplification, had a more favorable outcome. Unsupervised transcriptome analysis by NMF separated the discovery set into two groups with significantly different outcomes. A pathway-based approach identified a high-risk bone differentiation signature comprised of genes highly correlated with the expression of the osteogenic transcription factors. NMF analysis of DNA methylation and miRNA data also partitioned the discovery set into two groups with the methylation groups significantly correlated with clinical outcome. Our results provide a detailed picture of the genomic complexity and heterogeneity of these tumors that suggests a model wherein most OS are initiated by TP53 loss in a proliferative cell of the osteoblast lineage. TP53 deficiency leads directly to impairment of cell cycle control, DNA repair, and terminal differentiation, a state permissive for the development of secondary CNA and epigenetic changes. The TARGET OS data are publicly available (phs000218) and of immediate relevance to future investigations of the molecular mechanisms driving osteosarcoma. Findings suggest a path forward to improved assessment of risk for individual patients and support a precision medicine approach to future clinical trial development.

Citation Format: Paul S. Meltzer, Sean Davis, Jack Zhu, Yonghong Wang, Sven Bilke, Joshua Waterfall, Robert Walker, Marbin Pineda, Yuan Jiang, Sharon Savage, Lisa Mirabello, Tsz-Kwong Man, Aaron Taylor, Monika J. Sun, Jay Wunder, Irene Andrulis, Nalan Gokgoz, Shintaro Iwata, Miki Ohira, Mark Krailo, Don Barkauskas, Lisa Teot, Timothy Triche, Silvia de Toledo, Antonio S. Petrilli, Jaime M. Guidry Auvil, Richard Gorlick, Malcolm A. Smith, Daniela Gerhard, Ching C. Lau. Translational and mechanistic implications of osteosarcoma genomics: A TARGET report [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr LB-307.

[Sarcoma]

Challenges in the treatment of sarcoma as a rare cancer include(1)inexperience of sarcoma physicians due to the small number of patients,(2)insufficient information due to the lack of evidence,(3)lack of opportunities to provide information to non-specialists and to educate young physicians,(4)low adherence to standard treatments presented in clinical practice guidelines,(5)insufficient number of researchers engaged in basic research on rare cancers and their research funds, and(6) low number of clinical trials for the development of orphan drugs. This paper describes the current status and future prospects for the centralization and networking of sarcoma treatment, problems in pathological diagnosis, clinical evidence creation, information provision and human resource development, and information dissemination and consultation support to sarcoma patients.

THU0231 IL-2 DRIVES THE CONVERSION OF T FOLLICULAR HELPER TO T FOLLICULAR REGULATORY CELLS THROUGH EPIGENETIC MODIFICATION IN SYSTEMIC LUPUS ERYTHEMATOSUS

Background:

Systemic lupus erythematosus (SLE) is a complex polygenic autoimmune disease characterized by immune-system aberrations. Among several types of immune cells, T follicular helper (Tfh) cells promote autoantibody production, whereas T follicular regulatory (Tfr) cells suppress Tfh-mediated antibody responses.(1)

Objectives:

To identify the characteristics of Tfr cells and to elucidate the mechanisms of conversion of Tfh cells to Tfr cells, we probed the phenotype of T helper cells in patients with SLE and underlying epigenetic modifications by cytokine-induced signal transducer and activators of transcription (STAT) family factors.

Methods:

Peripheral blood mononuclear cells from SLE patients (n=44) and healthy donors (HD; n=26) were analyzed by flow cytometry. Memory Tfh cells were sorted and cultured under stimulation with T cell receptor and various cytokines. Expression of characteristic markers and phosphorylation of STATs (p-STATs) were analyzed by flow cytometry and quantitation PCR. Histone modifications were evaluated by chromatin immunoprecipitation.

Results:

The proportion of CXCR5+FoxP3+Tfr cells in CD4+T cells tended to increase (2.1% vs 1.7%, p=0.17); however, that of CD4+CD45RA-FoxP3hiactivated Tfr cells in Tfr cells was decreased (4.8% vs 7.1%, p<0.05), while CD4+CD45RA-FoxP3lownon-suppressive Tfr cells was increased (50.1% vs 38.2%, p<0.01) in SLE compared to HD. The percentage of PD-1hiactivated Tfh cells was significantly higher in SLE compared to HD (15.7% vs 5.9%, p<0.01). Furthermore, active patients had a higher ratio of activated Tfh/Tfr cells compared to inactive patients. In vitro study showed that IL-2, but not other cytokines such as TGF-β1, IL-12, IL-27, and IL-35, induced the conversion of memory Tfh cells to functional Tfr cells characterized by CXCR5+Bcl6+Foxp3hipSTAT3+pSTAT5+cells. The loci ofFOXP3at STAT binding sites were marked by bivalent histone modifications. After IL-2 stimulation, STAT5 directly bound on FOXP3 gene loci accompanied by suppressing H3K27me3. Finally, we found that serum level of IL-2 was decreased in SLE and that stimulation with IL-2 suppressed the generation of CD38+CD27+B cells by ex vivo coculture assay using Tfh cells and B cells isolated from human blood.

Conclusion:

Our findings indicated that the regulatory function of Tfr cells is impaired due to the low ability of IL-2 production and that IL-2 restores the function of Tfr cells through conversion of Tfh cells to Tfr cells in SLE. Thus, the reinstatement of the balance between Tfh and Tfr cells will provide important therapeutic approaches for SLE.

References:

[1]Deng J, Wei Y, Fonseca VR, et al. T follicular helper cells and T follicular regulatory cells in rheumatic diseases. Nat Rev Rheumatol. 2019; 15 (8): 475-90.

Disclosure of Interests: :

He Hao: None declared, Shingo Nakayamada Grant/research support from: Mitsubishi-Tanabe, Takeda, Novartis and MSD, Speakers bureau: Bristol-Myers, Sanofi, Abbvie, Eisai, Eli Lilly, Chugai, Asahi-kasei and Pfizer, Yamagata Kaoru: None declared, Naoaki Ohkubo: None declared, Shigeru Iwata: None declared, Yoshiya Tanaka Grant/research support from: Asahi-kasei, Astellas, Mitsubishi-Tanabe, Chugai, Takeda, Sanofi, Bristol-Myers, UCB, Daiichi-Sankyo, Eisai, Pfizer, and Ono, Consultant of: Abbvie, Astellas, Bristol-Myers Squibb, Eli Lilly, Pfizer, Speakers bureau: Daiichi-Sankyo, Astellas, Chugai, Eli Lilly, Pfizer, AbbVie, YL Biologics, Bristol-Myers, Takeda, Mitsubishi-Tanabe, Novartis, Eisai, Janssen, Sanofi, UCB, and Teijin