Clinical recommendations for treatment of localized angiosarcoma: A consensus paper by the Italian Sarcoma Group

Angiosarcoma (AS) represents a rare and aggressive vascular sarcoma, posing distinct challenges in clinical management compared to other sarcomas. While the current European Society of Medical Oncology (ESMO) clinical practice guidelines for sarcoma treatment are applicable to AS, its unique aggressiveness and diverse tumor presentations necessitate dedicated and detailed clinical recommendations, which are currently lacking. Notably, considerations regarding surgical extent, radiation therapy (RT), and neoadjuvant/adjuvant chemotherapy vary significantly in localized disease, depending on each different site of onset. Indeed, AS are one of the sarcoma types most sensitive to cytotoxic chemotherapy. Despite this, uncertainties persist regarding optimal management across different clinical presentations, highlighting the need for further investigation through clinical trials. The Italian Sarcoma Group (ISG) organized a consensus meeting on April 1st, 2023, in Castel San Pietro, Italy, bringing together Italian sarcoma experts from several disciplines and patient representatives from "Sofia nel Cuore Onlus" and the ISG patient advocacy working group. The objective was to develop specific clinical recommendations for managing localized AS within the existing framework of sarcoma clinical practice guidelines, accounting for potential practice variations among ISG institutions. The aim was to try to standardize and harmonize clinical practices, or at least highlight the open questions in the local management of the disease, to define the best evidence-based practice for the optimal approach of localized AS and generate the recommendations presented herein.

A Gradual Transition Toward Anaplasia in Wilms Tumor Through Tolerance to Genetic Damage

Patients with Wilms tumor (WT) in general have excellent survival, but the prognosis of patients belonging to the subgroup of WT with diffuse anaplasia (DA) is poor due to frequent resistance to chemotherapy. We hypothesized that DA WT cells might undergo changes, such as acquiring a persistent tolerance to DNA damage and copy number aberrations (CNAs), which could eventually lead to their resistance to chemotherapy treatment. Tissue sections from chemotherapy-treated DA WTs (n = 12) were compared with chemotherapy-treated nonanaplastic WTs (n = 15) in a tissue microarray system, enabling analysis of 769 tumor regions. All regions were scored for anaplastic features and immunohistochemistry was used to quantify p53 expression, proliferation index (Ki67), and DNA double-strand breaks (γH2AX). CNAs were assessed by array-based genotyping and TP53 mutations using targeted sequencing. Proliferation index and the frequency of DNA double-strand breaks (γH2AX dot expression) increased with higher anaplasia scores. Almost all (95.6%) areas with full-scale anaplasia had TP53 mutations or loss of heterozygosity, along with an increased amount of CNAs. Interestingly, areas with wild-type TP53 with loss of heterozygosity and only one feature of anaplasia (anaplasia score 1) also had significantly higher proliferation indices, more DNA double-strand breaks, and more CNAs than regions without any anaplastic features (score 0); such areas may be preanaplastic cell populations under selective pressure for TP53 mutations. In conclusion, we suggest that chemoresistance of DA WTs may be partly explained by a high proliferative capability of anaplastic cells, which also have a high burden of double-stranded DNA breaks and CNAs, and that there is a gradual emergence of anaplasia in WT.

Regorafenib in advanced solitary fibrous tumour: Results from an exploratory phase II clinical study

BACKGROUND

To investigate the activity of regorafenib in advanced solitary fibrous tumour (SFT).

METHODS

An Italian monocentric investigator-initiated exploratory single-arm Phase II trial was conducted of regorafenib in adult patients with advanced and progressive SFT, until progression or limiting toxicity. Prior treatment with antiangiogenics was allowed. Primary and secondary end-points were: overall response rate (ORR) by Choi criteria, and ORR by RECIST, progression-free survival (PFS), overall survival (OS).

RESULTS

From January 2016 to February 2021, 18 patients were enroled [malignant-SFT = 13; dedifferentiated-SFT (D-SFT) = 4; typical-SFT (T-SFT) = 1]. Fourteen patients were pre-treated, in 12 cases with antiangiogenics (median [m-] lines of treatment = 3). Sixteen patients were evaluable for response (one screening failure; one early discontinuation). Six/16 (35.2%) required a definitive dose reduction. ORR by Choi was 37.5% (95% CI: 15.2-64.6), with 6/16 (37.5%) partial responses (PR), 6/16 (37.5%) stable disease (SD) and 4/16 (25%) progressions; 5/6 responses occurred in patients pre-treated with antiangiogenics. No responses were detected in D-SFT. Best RECIST responses were: 1/16 (6.2%) PR, 12/16 (75%) SD, 3/16 (18.8%) progressions. At 48.4 month m-FU, m-PFS by Choi was 4.7 (inter-quartile range: 2.4-13.1) months, with 31.2% patients progression-free at 1 year.

CONCLUSION

Regorafenib showed activity in SFT, with 30% patients free-from-progression at one year. Responses were observed also in patients pretreated and refractory to another antiangiogenic agents. However, ORR and m-PFS were lower than reported with other antiangiogenics, and this was possibly due to discrepancies in the patient population and the high-rate of dose reductions.

Pathological and radiological response following neoadjuvant treatments in primary localized resectable myxofibrosarcoma and undifferentiated pleomorphic sarcoma of the extremities and trunk wall

BACKGROUND

To explore the correlation between pathological and radiological response to preoperative treatments and outcome in surgically treated patients with myxofibrosarcoma (MFS) and undifferentiated pleomorphic sarcoma (UPS).

METHODS

All consecutive patients with primary localized MFS and UPS of the extremities and trunk wall surgically treated with curative intent at our center (2005-2021) were included. Clinical data including residual visible tumor (VT%) on surgical specimen and Response Evaluation Criteria in Solid Tumor (RECIST) were retrieved. Kaplan-Meier curves for overall survival and disease-free survival, and cumulative incidence of local relapse and distant metastasis were estimated in a competing risk framework according to RECIST and VT%, overall and by treatment group. Cox and Fine and Gray multivariable models were performed.

RESULTS

Of 693 patients affected by primary MFS and UPS, 233 (66 MFS and 167 UPS) were treated by neoadjuvant chemotherapy (naChT), radiotherapy (naRT), or both (naChT-RT). VT% was ≤5% in 13/46 (28.2%), 24/99 (24.2%), and 40/88 (45.4%) patients, respectively. There were 11/46 (29.7%), 22/99 (22.7%), and 23/88 (26.1%) RECIST partial responses and 18/46 (48.6%), 59/99 (60.8%), and 60/88 (68.2%) RECIST stable disease, respectively. In naChT, a trend for a better survival was observed when VT% ≤5% (p = .09), whereas RECIST partial responses and stable disease had the same outcome. VT% was not associated with outcome in naRT or naChT-RT, whereas RECIST response was.

CONCLUSION

In primary localized MFS and UPS treated with neoadjuvant therapies, VT% seems more relevant than size reduction after naChT, whereas the opposite is true when naRT is administered alone or concurrent to ChT.

Treating secondary malignant neoplasms: A burden of childhood cancer survivors

Each year approximately 35,000 children and adolescents are diagnosed with cancer in Europe. Five-year survival rates have improved and now reach 80% in most European countries, thanks to a combination of chemotherapy, radiotherapy, and surgery. To date, there are more than 44,000 Italians still living several years after being diagnosed with cancer in developmental age. The risk of premature morbidity and mortality for cancer survivors is well known and documented. Approximately 60% of survivors of cancer in childhood and adolescence have at least one chronic health condition in later life, and more than one in four develop severe or life-threatening disorders. Among the various long-term iatrogenic sequelae of cancer treatments, the most worrisome are second malignant neoplasms. We reported on our mono-institutional experiences of screening and treating secondary breast cancer, secondary thyroid cancer and secondary osteosarcoma. Recommendations on the surveillance needed for cancer survivors because of the risk of late effects of their disease or its treatment suggest that discussing the potential problems early on can be crucial to a patient's future health. These considerations and our consolidated experience strengthen our conviction that survivors of cancer in childhood and adolescence who develop second malignant neoplasms should be treated at highly-specialized centers. Multidisciplinary care requires close communications and high levels of up-to-date professional expertise. This challenging area of health care is also changing rapidly because cancer survivorship is a work in progress, but we cannot wait for definitive conclusions on many aspects because this will take decades, especially for pediatric patients.

Effectiveness of irinotecan plus trabectedin in a desmoplastic small round cell tumor patient-derived xenograft

This study exploited a novel patient-derived xenograft (PDX) of desmoplastic small round cell tumor (DSRCT), which reproduces histomorphological and molecular characteristics of the clinical tumor, to assess the activity of cytotoxic and targeted anticancer agents. Anti-tumor effect was moderate for doxorubicin, pazopanib, and larotrectenib [maximum tumor volume inhibition (max TVI): 55-66%] while trabectedin had higher activity (max TVI: 82%). Vinorelbine, irinotecan, and eribulin achieved a nearly complete tumor growth inhibition (max TVI: 96-98%), although tumors regrow after the end of treatment. Combination of irinotecan with either eribulin or trabectedin resulted in complete responses which were maintained until the end of the experiment for irinotecan plus trabectedin. Irinotecan-based combinations nearly abrogated the expression of proteins of the G2/M checkpoint preventing cell entrance in mitosis and induced apoptotic and necroptotic cell death. Consistently, irinotecan plus trabectedin resulted in a reprogramming of DSCRT transcriptome with a downregulation of E2F targets, G2/M checkpoint, and mitotic spindle gene sets. This study emphasizes the importance of patient-derived pre-clinical models to explore new treatments in DSRCT and fosters clinical investigation in the activity of irinotecan plus trabectedin.

Abstract 6726: Effectiveness of irinotecan plus trabectedin in a desmoplastic small round cell tumor patient-derived xenograft

Desmoplastic small round cell tumor (DSRCT) is a ultra-rare pediatric scarcoma with poor overall survival. This tumor is dependent on the continued expression and activity of its pathognomonic molecular lesion, the EWS-WT1 transcription factor. DSRCT is often treated with multimodal approach of chemotherapy, surgery, and radiotherapy. Given the rarity of the disease, there have not been clinical studies to establish an effective therapeutic regimen. Indeed, the development of fully characterized preclinical models, able to reproduce the molecular characteristics of clinical tumors, appears instrumental for testing novel therapeutic strategies and accelerating the translation of preclinical findings to the clinical practice. In this study we exploited a novel DSRCT patient-derived xenograft (PDX), which reproduces histomorphological, genomic (CNV) and transcriptomic characteristics of the paired clinical tumor, to comparatively assess the activity of cytotoxic and targeted anticancer agents. Anti-tumor effect was moderate for single-agent doxorubicin, pazopanib and larotrectenib [maximum tumor volume inhibition (max TVI): 55-66%], trabectedin had a higher effect (max TVI: 82%) while irinotecan and eribulin almost complete inhibited tumor growth (max TVI: 96% and 98%, respectively). Interestingly, combination of irinotecan with either eribulin or trabectedin resulted in complete responses which were maintained until the end of the experiment for irinotecan + trabectedin. The trabectedin + irinotecan combination markedly reduced the expression of anti-apoptotic proteins and caused caspase-3 cleavage, consistent with an apoptotic response, and also induced the accumulation of phospho-RIP1 (Ser166) and phospho-RIP3 (Ser227), indicating the occurrence of necroptosis, a type of programmed cell death with necrotic morphology. In line with these findings, transcriptomic profile analysis of ex-vivo tumor samples obtained from mice exposed to trabectedin ± irinotecan revealed a reduced expression of the biological pathways related to apoptosis and cell proliferation in tumor exposed to the drug combination. Mechanistically, we found that these effects were mediated, at least in part, by the down-regulation of EWS-WT1 chimeric protein and its downstream targets, as assessed by PCR and western blotting. Overall, this study emphasizes the importance of patient-derived pre-clinical models to explore new treatments in DSRCT and fosters clinical investigation in the activity of irinotecan plus trabectedin, providing a step forward for developing more effective trabectedin-based combinations for DSRCT to be tested in clinical trials.

Citation Format: Valentina Zuco, Sandro Pasquali, Monica Tortoreto, Stefano Percio, Valentina Doldi, Marta Barisella, Paola Collini, Gianpaolo Dagrada, Silvia Brich, Patrizia Gasparini, Marco Fiore, Michela Casanova, Anna Maria Frezza, Alessandro Gronchi, Silvia Stacchiotti, Andrea Ferrari, Nadia Zaffaroni. Effectiveness of irinotecan plus trabectedin in a desmoplastic small round cell tumor patient-derived xenograft. [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 6726.

Abstract 2245: The transcriptomic profile of retroperitoneal primary well differentiated liposarcoma (WDLPS) and well differentiated (WD)/dedifferentiated (DD) components of DD liposarcoma (DDLPS) reveals the progression from WDLPS to DDLPS

This study aimed at unravelling whether WDLPS undergo a progressive evolution to DDLPS through analyzing the transcriptomic profile of retroperitoneal liposarcoma. In a contemporary retrospective series of primary retroperitoneal DDLPS and WDLPS (N=107), we sampled paired DD/WD/normal fat (NF) components of DDLPS and paired WD/NF components of WDLPS. RNA-Seq data was normalized using the trimmed mean of M-value (TMM) algorithm, heteroscedasticity was removed, and differential expression analysis (DEA) performed. Gene sets enrichment analysis (GSEA) evaluated enrichment in biological hallmarks and was performed to overcome FDR correction of DEA and evaluate the ensemble. FDR threshold 0.05 was considered for significance. Marked transcriptional changes exist among paired components of DDLPS (DD, WD, NF) or WDLPS (WD, NF). Although DEA did not show significant changes between WD and NF components of DDLPS and WDLPS, GSEA analysis highlighted deregulation in hallmarks. An upregulation of G2M checkpoint and mitotic spindle gene sets was observed when WD components of DDLPS was compared to WDLPS and progressively increase in the DD component. Some targetable genes from the leading edge of these pathways (PLK1, AURKA, and EZH2) as well as the primary oncogenic drivers (MDM2, CDK4, and HMGA2) of liposarcoma were functionally validated with targeted agents in cell lines of DDLPS and WDLPS, supporting findings of transcriptomic analysis. We also observed that adipogenesis, fatty acid metabolism, cholesterol homeostasis, oxidative phosphorylation, and peroxisome gene sets were down-regulated in the DD component, while glycolysis was upregulated compared to WD components. When NF were compared with their paired tumor components, G2M checkpoint and mitotic spindle gene sets did not differ between DDLPS and WDLPS, suggesting these two hallmarks as tumor-specific. NF of patients with DDLPS demonstrated higher expression of adipogenesis, and other pathways related to metabolism suggesting its metabolic activation compared to NF of patients with WDLPS. In conclusion, changes distinguishing WDLPS/DDLPS early at the WD stage and progressively increasing in the DD component of DDLPS supported the hypothesis of an orderly progression from WDLPS to DDLPS and represent a source of additional therapeutic targets.

Citation Format: Sandro Pasquali, Stefano Percio, Dario Callegaro, Silvia Martini, Alessia Beretta, Alessia Bertolotti, Silvia Brich, Paola Collini, Marta Barisella, Loris De Cecco, Viviana Vallacchi, Silvia Stacchiotti, Matteo Benelli, Alessandro Gronchi, Nadia Zaffaroni. The transcriptomic profile of retroperitoneal primary well differentiated liposarcoma (WDLPS) and well differentiated (WD)/dedifferentiated (DD) components of DD liposarcoma (DDLPS) reveals the progression from WDLPS to DDLPS [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 2245.

Long-term survivors with desmoplastic small round cell tumor (DSRCT): Results from a retrospective single-institution case series analysis

OBJECTIVE

To report on a retrospective study of primary DSRCT aiming at characterizing long-term survivors (LTS).

METHODS

All consecutive patients treated at our institution for a primary DSRCT between 2000 and 2021 were retrospectively identified. Patients received multiagent chemotherapy ± surgery ± hyperthermic intraperitoneal chemotherapy (HIPEC) ± whole abdomino-pelvic radiotherapy (WAP-RT) ± high-dose chemotherapy ± maintenance chemotherapy (MC). Event-free survival (EFS) and overall survival (OS) were estimated by Kaplan-Meier method. Patients alive, without evidence of disease at ≥36 months from diagnosis, were defined as LTS.

RESULTS

Thirty-eight patients were identified. All received multiagent chemotherapy; 27/38 (71%) surgery (7/27 [26%] plus HIPEC), 9/38 (24%) WAP-RT, 12/38 (32%) MC. At a median-follow-up of 37 months (IQR 18-63), overall median-EFS and median-OS were 15 and 37 months, respectively. All events occurred within 35 months. In patients who underwent surgery, median-EFS and median-OS were 19 and 37 months (23 and 43 months after R0/R1, and 10 and 19 months after R2 resection), respectively. LTS were 5/38 (13%), alive at 37, 39, 53, 64, 209 months. None had liver or extra-abdominal metastasis at diagnosis, they all received R0/R1 resection, 3/5 had WAP-RT, 2/5 MC, 1/5 received high-dose chemotherapy, none HIPEC.

CONCLUSIONS

In our series cure was likely achieved in 13% of DSRCT. LTS had no liver/extra-abdominal disease, were treated with complete surgery, and possibly WAP-RT/MC.

Gene expression-based dissection of inter-histotypes, intra-histotype and intra-tumor heterogeneity in pediatric tumors

Intra-tumor heterogeneity (ITH) fosters tumor evolution, resistance to therapy, and relapse. Recently, many evidence have been accumulated on the occurrence of genetic ITH in pediatric cancers. With this study we aimed to address the downstream effects that genetic and epigenetic ITH, and tumor-microenvironment interactions may produce within a tumor mass. To this aim, we investigated by high-throughput gene expression multiple samples of 5 hepatoblastomas, 5 neuroblastomas, 5 rhabdomyosarcomas, and 5 Wilms tumors. Principal component analysis, single sample hallmark gene sets analysis, and weighted gene co-expression network analysis were performed on gene expression data. We observed that the different tumors clustered by histotype, and then by case, and in addition, a variable degree of ITH was visible in all the investigated cases. The ITH highlighted in this study can represent a challenge in tumor treatment since we demonstrated that different druggable hallmarks and targets may be heterogeneously present within the same tumor mass, and this can potentially lead to therapeutic failure. Despite this heterogeneity, we could highlight some commonalities among the different histotypes investigated, supporting the feasibility to move in the clinic from a histotype-driven to a target-driven, sometimes agnostic, approach at least in some cases.

Establishment of 6 pediatric rhabdomyosarcoma patient’s derived xenograft models closely recapitulating patients’ tumor characteristics

Introduction:

The prognosis for patients with metastatic and recurrent pediatric rhabdomyosarcoma (RMS) remains poor. The availability of preclinical models is essential to identify promising treatments We established a series of pediatric RMS patient derived xenografts (PDXs), all faithfully mirroring primary tumor characteristics and representing a unique tool for clarifying the biological processes underlying RMS progression and relapse.

Methods:

Fresh tumor samples from 12 RMS patients were implanted subcutaneously in both flanks of immunocompromised mice. PDXs were considered as grafted after accomplishing three passages in mice. Characterization of tumor tissues and models was performed by comparing both morphology and immunoistochemical and fluorescence in situ hybridization (FISH) characteristics.

Results:

Six PDXs were established, with a successful take rate of 50%. All models closely mirrored parental tumor characteristics. An increased grafting rate for tumors derived from patients with worse outcome (p = 0.006) was detected. For 50% PDXs grafting occurred when the corresponding patient was still alive.

Conclusion:

Our findings increase the number of available RMS PDX models and strengthen the role of PDXs as useful preclinical tools for patients with unmet medical needs and to develop personalized therapies.

A transcriptomic analysis of retroperitoneal well differentiated liposarcoma (WDLPS) and well differentiated (WD) and dedifferentiated (DD) components of dedifferentiated liposarcoma (DDLPS)

e23520

Background: Retroperitoneal DDLPS is an aggressive tumor characterized by a WD component, morphologically similar to a WDLPS, and a DD component that drives patient prognosis. We aimed at unraveling whether WDLPS and DDLPS are distinct entities or entail a progressive evolution from WDLPS to DDLPS through a transcriptomic analysis. Methods: A transcriptomic analysis was performed in a retrospective series of 107 patients with primary retroperitoneal WDLPS (N = 68, 63.5%) or DDLPS (N = 39, 36.5%) who underwent surgery (2011-15). Paired DD, WD, and normal fat (NF) components were sampled in DDLPS, while paired WD and NF components were sampled in WDLPS. RNA-Seq data were normalized according to the trimmed mean of M-value (TMM) algorithm and differential expression was evaluated with the voom method implemented into the edgeR package. Enrichment in hallmark gene sets from Molecular Signatures Database (MSigDB) was evaluated with gene sets enrichment analysis (GSEA), by using t-statistic as measure of ranking. A false discovery rate (FDR) adjusted p-value < 0.05 was considered for statistical significance. Results: Differential expression analysis revealed marked transcriptional changes within paired components of DDLPS (DD, WD, NF) and WDLPS (WD, NF). Changes of WD and NF components between WDLPS and DDLPS were not statistically significant. Gene sets were analyzed to evaluate the ensemble and overcome the FDR correction applied to single genes. Hallmarks deregulated in WD component of DDLPS compared to WDLPS were detected also in their paired DD component. Among them, G2M checkpoint and mitotic spindle were up-regulated, while adipogenesis, fatty acid metabolism, cholesterol homeostasis, oxidative phosphorylation, and peroxisome were down-regulated. These differences persisted also when NF components were compared with their paired WD component of DDLPS and WDLPS. G2M checkpoint and mitotic spindle gene sets did not differ between NF of DDLPS and NF of WDLPS, suggesting these two hallmarks as tumor-specific. Conversely, expression of adipogenesis, fatty acid metabolism, and oxidative phosphorylation was up-regulated together with other gene sets related to metabolism in NF of DDLPS. Tumor inflammation and interferon response were up-regulated in WD components compared to their paired NF components. Also, interferon response was down-regulated in WD component of DDLPS compared to WDLPS, and inflammation was down-regulated in DD component compared to both WD components. Conclusions: Transcriptomic changes that distinguished WDLPS and WD component of DDLPS increased progressively also in the paired DD component of DDLPS, supporting the hypothesis of a progression from WDLPS to DDLPS in some liposarcomas. Changes observed in NF may suggest a paracrine effect sustaining tumor dedifferentiation.

SELNET clinical practice guidelines for bone sarcoma

Bone sarcoma are infrequent diseases, representing < 0.2% of all adult neoplasms. A multidisciplinary management within reference centers for sarcoma, with discussion of the diagnostic and therapeutic strategies within an expert multidisciplinary tumour board, is essential for these patients, given its heterogeneity and low frequency. This approach leads to an improvement in patient's outcome, as demonstrated in several studies. The Sarcoma European Latin-American Network (SELNET), aims to improve clinical outcome in sarcoma care, with a special focus in Latin-American countries. These Clinical Practice Guidelines (CPG) have been developed and agreed by a multidisciplinary expert group (including medical and radiation oncologist, surgical oncologist, orthopaedic surgeons, radiologist, pathologist, molecular biologist and representatives of patients advocacy groups) of the SELNET consortium, and are conceived to provide the standard approach to diagnosis, treatment and follow-up of bone sarcoma patients in the Latin-American context.

Pathology of Wilms' tumour in International Society of Paediatric Oncology (SIOP) and Children's Oncology Group (COG) renal tumour studies: similarities and differences

Excellent outcomes for patients with Wilms' tumour (WT), over 90% for all stages together, have been achieved through researching WT in multicentre and multinational trials and studies in the last 50 years, led by two major groups - International Society of Paediatric Oncology (SIOP) and Children's Oncology Group (COG, previously National Wilms' Tumor Study Group). Despite having different approaches, the survival outcomes in two groups are remarkably similar. In general, in SIOP, which is followed in Europe and most other countries around the world, patients are first treated with pre-operative chemotherapy, followed by surgery and, if necessary, post-operative chemotherapy and radiotherapy. In COG, which is mainly followed in North America, patients are treated with upfront surgery, followed, if necessary, by post-operative chemotherapy and radiotherapy. In both groups, post-operative treatment primarily depends on tumour histological classification and stage, although in recent studies, other prognostic factors have been included, too (tumour volume, response to preoperative chemotherapy, molecular markers). Due to separate initial treatments, there are differences in histological assessment and subtyping of WT, and, more importantly, in staging criteria. In this review, we discuss the similarities and differences between the two groups in order to help pathologists who are dealing with WT to understand and follow the pathological protocol which is appropriate for a particular case since in many centres both approaches may be followed depending on individual case's / patient's circumstances.

Renal cell carcinoma in children and adolescents: A retrospective study of a French-Italian series of 93 cases

BACKGROUND

Renal cell carcinomas represent 2 to 5% of kidney malignancies in children and adolescents. Appropriate diagnostic and classification are crucial for the correct management of the patients and in order to avoid inappropriate preoperative chemotherapy, which is usually recommended if a Wilms tumor is suspected.

METHODS

a French-Italian series of 93 renal cell carcinomas collected from 1990 to 2019 in patients aged less than 18 years old was reclassified according to the 2016 WHO classification and the latest literature. TFE3 and TFEB FISH analyses and a panel of immunohistochemical stains were applied.

RESULTS

The median age at diagnosis was 11 years (range: 9 months - 17 years). MiT family (MiTF) translocation renal cell carcinomas accounted for 52% of the tumors, followed by papillary renal cell carcinomas (20%) and unclassified renal cell carcinomas (13%). Other subtypes, such as SDHB-deficient and Fumarate hydratase-deficient renal cell carcinomas, represented 1 to 3% of the cases. We also described a case of ALK-rearranged renal cell carcinoma with a metanephric adenoma-like morphology.

CONCLUSION

A precise histological diagnosis is mandatory as targeted therapy could be applied for some RCC subtypes, i.e., MiTF-translocation and ALK-translocation renal cell carcinomas. Moreover, some RCC subtypes may be associated with a predisposition syndrome that will impact patients' and family's management and genetic counseling. A precise RCC subtype is also mandatory for the clinical management of the patients and the inclusion in new prospective clinical trials.

A prospective observational study of Active surveillance in primary desmoid fibromatosis

PURPOSE

To prospectively assess the behaviour of primary sporadic (not FAP associated) desmoid fibromatosis (DF) managed by active surveillance (AS).

EXPERIMENTAL DESIGN

This is an Italian prospective, multicenter, observational study (NCT02547831) including patients {greater than or equal to}16 years with primary sporadic DF at any site. Patients were assessed by Response Evaluation Criteria in Solid Tumor (RECIST) version 1.1 . Primary end-point was progression-free survival (PFS) at 3 years. Treatment-free survival (TFS) was also analyzed. PFS and TFS were calculated by Kaplan-Meier plots and compared by log-rank test Cox proportional-hazard multivariable regression analyses were performed.

RESULTS

From 2013 to 2018 108 consecutive patients were included (82% female); median age was 39-yr; median size was 51 mm. CTNNB1 mutations were: T41A (50%); S45F (12%); other (19%); WT (19%). At 32.3-month median-FU, 42/108 (39%) showed RECIST progression. Spontaneous regression (SR) was initially observed in 27/108 (25%), while it followed dimensional progression in other 33/108 (31%). PFS at 36 months was 54.5% (95% CI, 44.9%-66.1%). Thirty-five/108 (32%) patients received active treatments, 18/108 (17%) after RECIST progression and 17/108 (15%) after symptomatic progression. TFS at 36 months was 65.9% (95% CI, 57.3%-75.9%). Larger tumor size and extremity location were associated to shorter TFS and a trend for S45F mutation was also observed (p=0.06), while none of the above variables was significantly associated to PFS.

CONCLUSIONS

In primary DF, AS can be proposed, since disease stabilization and SR frequently occur. However extra care should be taken for patients with tumors of larger size, extremity location and S45F mutation.

Systemic treatment in advanced phyllodes tumor of the breast: a multi-institutional European retrospective case-series analyses

BACKGROUND

We aimed at investigating outcome of systemic treatments in advanced breast PT.

METHODS

All cases of advanced breast PT treated with systemic treatments from 1999 to 2019, in one of the referral sarcoma centers involved in the study, were retrospectively reviewed.

RESULTS

56 female patients were identified. Median age was 52 (range of 25-76) years. Patients received a median number of 2 systemic treatments (range of 1-4). Best responses according to RECIST were 1 (3.7%) CR, 11 (40.7%) PR, 6 (22.2%) SD, 9 (33.3%) PD with anthracyclines plus ifosfamide (AI); 2 (16.7%) PR, 4 (33.3%) SD, 6 (50.0%) PD with anthracycline alone; 3 (18.8%) PR, 4 (25.0%) SD, 9 (56.3%) PD with high-dose ifosfamide given as a continuous infusion (HD-IFX); 3 (20.0%) SD, 12 (80.0%) PD with a gemcitabine-based regimen (with 2 patients not evaluable); 1 (8.3%) PR, 2 (16.7%) SD, 9 (75.0%) PD with trabectedin (with 1 patient not evaluable); 1 (16.7%) PR, 1 (16.7%) SD, 4 (66.7%) PD with tyrosine-kinase inhibitors (TKI). The median PFS were 5.7 (IQR 2.5-9.1) months with AI; 3.2 (IQR 2.2-5.0) months with anthracycline alone; 3.4 (IQR 1.4-6.7) months with HD-IFX; 2.1 (IQR 1.4-5.2) months with gemcitabine-based chemotherapy; 1.8 (IQR 0.7-6.6) months with trabectedin; 3.4 (IQR 3.1-3.8) months with TKI. With a median follow-up of 35.3 (IQR 17.6-66.9) months, OS from the start of first-line systemic treatment was 15.2 (IQR 7.6-39.6) months.

CONCLUSION

In this series of advanced PT (to our knowledge, the largest reported so far), AI was associated with a high rate of responses, however, with a median PFS of 5.7 months. Other systemic treatments were poorly active.

Targeted RNA-sequencing analysis for fusion transcripts detection in tumor diagnostics: assessment of bioinformatic tools reliability in FFPE samples

Aim:

Diagnostic laboratories are progressively introducing next-generation sequencing (NGS) technologies in the routine workflow to meet the increasing clinical need for comprehensive molecular characterization in cancer patients for diagnosis and precision medicine, including fusion-transcripts detection. Nevertheless, the low quality of messenger RNA (mRNA) extracted from formalin-fixed paraffin-embedded (FFPE) samples may affect the transition from traditional single-gene testing approaches [like fluorescence in situ hybridization (FISH), immunohistochemistry (IHC), or polymerase chain reaction (PCR)] to NGS. The present study is aimed at assessing the overall accuracy of RNA fusion transcripts detection by NGS analysis in FFPE samples in real-world diagnostics.

Methods:

Herein, NGS data from 190 soft tissue tumors (STTs) and carcinoma cases, discussed in the context of the institutional Molecular Tumor Board, are reported and analyzed by FusionPlex^© Solid tumor kit through the manufacturer’s pipeline and by two well-known fast and accurate open-source tools [Arriba (ARR) and spliced transcripts alignment to reference (STAR)-fusion (SFU)].

Results:

The combination of FusionPlex^© Solid tumor with ArcherDX^® Analysis suite (ADx) analysis package has been proven to be sensitive and specific in STT samples, while partial loss of sensitivity has been found in carcinoma specimens.

Conclusions:

Albeit ARR and SFU showed lower sensitivity, the use of additional fusion-detection tools can contribute to reinforcing or extending the output obtained by ADx, particularly in the case of low-quality input data. Overall, our results sustain the clinical use of NGS for the detection of fusion transcripts in FFPE material.

Predictive Value of MRP-1 in Localized High-Risk Soft Tissue Sarcomas: A Translational Research Associated to ISG-STS 1001 Randomized Phase III Trial

MRP-1 is implicated in multidrug resistance and was described as prognostic in high-risk patients with soft-tissue sarcoma (STS) in a previous study. The current research aimed to validate MRP-1 prognostic/predictive value in localized sarcomas treated with anthracyclines plus ifosfamide within the ISG-1001 phase III study. In addition, the inhibitory activity on MRP-1 was investigated in preclinical studies to identify new combinations able to increase the efficacy of standard chemotherapy in STS. MRP-1 expression was assessed by IHC in tissue microarrays from patients with STS and tested for correlation with disease-free survival (DFS) and overall survival (OS). In vitro studies tested the efficacy of MRP-1 inhibitors (nilotinib, ripretinib, selumetinib, and avapritinib) in sarcoma cell lines. The effect of combinations of the most active MRP-1 inhibitors and chemotherapy was measured on the basis of apoptosis. MRP-1 was evaluable in 231 of 264 cases who entered the study. MRP-1 expression (strong intensity) was independently associated with worse DFS [HR, 1.78; 95% confidence interval (CI), 1.11-2.83; P = 0.016], in the multivariate analysis, with a trend for a worse OS (HR, 1.78; 95% CI, 0.97-3.25; P = 0.062). In vitro studies showed that the addition of MRP-1 inhibitors (nilotinib or avapritinib) to doxorubicin plus palifosfamide, significantly increased cell death in SK-UT-1 and CP0024 cell lines. MRP-1 is an adverse predictive factor in localized high-risk patients with STS treated with neoadjuvant anthracyclines plus ifosfamide followed by surgery. In vitro findings support the clinical assessment of the combination of chemotherapy and MRP-1 inhibitors as a promising strategy to overcome the drug ceiling effect for chemotherapy.

Clinical heterogeneity and reduced penetrance in DICER1 syndrome: a report of three families

INTRODUCTION

DICER1 syndrome is characterized by increased susceptibility to malignancies, mostly occurring in childhood. The range of phenotypic effects of DICER1 variants is under investigation, and the syndrome's phenotypic spectrum is steadily widening. We report on three Italian families showing heterogeneous clinical presentation and reduced penetrance in family members.

CASE DESCRIPTIONS

Patient 1 is a 10-year-old girl with a Sertoli-Leydig cell tumor. Although family history was unremarkable, genetic testing identified a DICER1 germline variant, inherited from her healthy father. Benign thyroid nodules were subsequently diagnosed in both the proband and her father. Patient 2 is an 8-month-old boy with type 1 pleuropulmonary blastoma. His sister developed a nephroblastoma at age 2 years. A DICER1 novel variant was identified in both siblings and their healthy father. Patient 3 is a 22-year-old man who developed a spinal extramedullary intradural mass diagnosed as rhabdomyosarcoma with a peculiar tubular, gland-like component. Tumor testing revealed two pathogenic DICER1 variants, one of which was confirmed to be germline and identified in his 17-year-old healthy brother and in his father, who showed multiple thyroid nodules.

CONCLUSIONS

Among our patients, three developed tumors most frequently associated with DICER1 syndrome (i.e. pleuropulmonary blastoma, nephroblastoma, and Sertoli-Leydig cell tumor). One developed a peculiar sarcoma of the spinal cord not previously described in DICER1 syndrome. Genetic testing in relatives highlighted the paternal origin and reduced penetrance in all families, with thyroid benign lesions as the most common features in otherwise unaffected individuals.

Analysis of the mutational status of SIX1/2 and microRNA processing genes in paired primary and relapsed Wilms tumors and association with relapse

Whereas 90% of patients with Wilms tumor (WT) reach cure, approximately half of patients developing a recurrent tumor die of the disease. Therefore, to disclose events leading to recurrence represents a clinical need. To study paired primary/recurrent tumor samples, being aware of the intra-tumoral heterogeneity, might help finding these answers. We previously suggested that mutations in SIX1 and DROSHA underlie WT recurrence. With the aim to better investigate this scenario, we collected 19 paired primary/recurrent tumors and 10 primary tumors from relapsing patients and searched for mutations in the SIX1/2 genes and microRNA processing genes (miRNAPGs). We found SIX1 mutation in one case, miRNAPGs mutations in seven cases, and the co-occurrence of SIX1 and miRNAPG mutations in one case. We could observe that, whereas in primary tumors the mutations could be heterogeneously present, in all cases they were positively selected and homogeneously present in the recurrent disease, as also indicated by a "moderate" and "almost perfect" agreement (according to the Landis and Koch classification criteria) between paired samples. Analysis of SIX1/2 genes and miRNAPGs in 50 non-relapsing WTs disclosed SIX2 mutation in one case and miRNAPGs mutations in seven. A borderline statistically significant association was observed between miRNAPGs mutations and the occurrence of relapse (p value: 0.05). These data suggest that SIX1 and miRNAPGs mutations may provide an advantage during tumor progression to recurrence and can represent oncogenic drivers in WT development.

Rechallenge of denosumab in jaw osteonecrosis of patients with unresectable giant cell tumour of bone: a case series analysis and literature review

Objectives

Giant cell tumour of bone (GCTB) is a rare tumour, generally managed with surgery. Treatment of the very rare unresectable advanced/metastatic GCTB is challenging and denosumab is the only current available medical option, an anti-RANKL monoclonal antibody inhibiting osteolysis. An uncommon but severe and treatment-limiting adverse event of denosumab is the osteonecrosis of the jaw (ONJ). The clinical management of GCTB patients stopping denosumab for medication-related (MR)-ONJ and the possible reintroduction of denosumab after MR-ONJ resolution is matter of debate. We performed a retrospective study to describe the incidence, clinical features and outcome of MR-ONJ in unresectable GCTB patients treated with denosumab at our Institution.

Design and setting

Retrospective, single-institutional study.

Participants

Adult patients receiving denosumab as antineoplastic therapy for GCTB and experiencing MR-ONJ at Fondazione IRCCS Istituto Nazionale Tumori of Milan between January 2008 and July 2019.

Main outcome measures

Incidence, time of onset and clinical features of MR-ONJ.

Results

29 patients with locally advanced and/or metastatic GCTB treated with denosumab were identified. At a median follow-up of 70 months (range 1–125), 4 (13.8%) patients experienced MR-ONJ while on treatment, after 125, 119, 85 and 41 months of denosumab, respectively. All patients showed an ongoing tumour stabilisation with denosumab at the MR-ONJ onset and in all cases denosumab was stopped. All four patients were treated with ozone therapy. Two are waiting for surgery, two were already operated on. Both of them experienced disease progression and were thus rechallenged with denosumab. One is still on therapy after 25 months. The other had an MR-ONJ relapse after 39 months and was treated again with ozone therapy and surgery. She is under surveillance, GCTB being currently stable.

Conclusion

A clinical algorithm of denosumab rechallenge after complete resolution of MR-ONJ in progressing GCTB patients should be prospectively validated.

Molecular Determinants of Soft Tissue Sarcoma Immunity: Targets for Immune Intervention

Soft tissue sarcomas (STSs) are a family of rare malignant tumors encompassing more than 80 histologies. Current therapies for metastatic STS, a condition that affects roughly half of patients, have limited efficacy, making innovative therapeutic strategies urgently needed. From a molecular point of view, STSs can be classified as translocation-related and those with a heavily rearranged genotype. Although only the latter display an increased mutational burden, molecular profiles suggestive of an “immune hot” tumor microenvironment are observed across STS histologies, and response to immunotherapy has been reported in both translocation-related and genetic complex STSs. These data reinforce the notion that immunity in STSs is multifaceted and influenced by both genetic and epigenetic determinants. Cumulative evidence indicates that a fine characterization of STSs at different levels is required to identify biomarkers predictive of immunotherapy response and to discover targetable pathways to switch on the immune sensitivity of “immune cold” tumors. In this review, we will summarize recent findings on the interplay between genetic landscape, molecular profiling and immunity in STSs. Immunological and molecular features will be discussed for their prognostic value in selected STS histologies. Finally, the local and systemic immunomodulatory effects of the targeted drugs imatinib and sunitinib will be discussed.

Complexity index in sarcoma and genomic grade index gene signatures in rhabdomyosarcoma of pediatric and adult ages

BACKGROUND

Rhabdomyosarcoma (RMS), the most frequent soft-tissue sarcoma in childhood, shows extensive heterogeneity in histology, site and age of onset, clinical course, and prognosis. Adolescents and young adults (AYA) with RMS form a subgroup of patients whose survival lacks behind that of children while diagnosed with histologically similar tumors.

PROCEDURES

A 67-gene prognostic signature related to chromosome integrity, mitotic control, and genome complexity in sarcomas (CINSARC) is considered a powerful tool for identifying tumors with a highly metastatic potential. With this study, we investigated the prognostic value of CINSARC signature on a cohort of 48 pediatric (PEDs) and AYAs-RMS.

RESULTS

CINSARC resulted not significantly correlated with age, suggesting other determinants to be responsible for that difference in survival. It remained a significant prognostic variable in both the groups of PEDs and AYAs. Also, genomic grade index signature was tested on the same cohort and showed very similar results with CINSARC.

CONCLUSIONS

Our study showed that CINSARC correlated with outcome in RMS patients and may be potentially considered a tool to predict outcome, and so stratify RMS patients.

Characteristics and outcome of pediatric renal cell carcinoma patients registered in the International Society of Pediatric Oncology (SIOP) 93-01, 2001 and UK-IMPORT database: A report of the SIOP-Renal Tumor Study Group

In children, renal cell carcinoma (RCC) is rare. This study is the first report of pediatric patients with RCC registered by the International Society of Pediatric Oncology-Renal Tumor Study Group (SIOP-RTSG). Pediatric patients with histologically confirmed RCC, registered in SIOP 93-01, 2001 and UK-IMPORT databases, were included. Event-free survival (EFS) and overall survival (OS) were analyzed using the Kaplan-Meier method. Between 1993 and 2019, 122 pediatric patients with RCC were registered. Available detailed data (n = 111) revealed 56 localized, 30 regionally advanced, 25 metastatic and no bilateral cases. Histological classification according to World Health Organization 2004, including immunohistochemical and molecular testing for transcription factor E3 (TFE3) and/or EB (TFEB) translocation, was available for 65/122 patients. In this group, the most common histological subtypes were translocation type RCC (MiT-RCC) (36/64, 56.3%), papillary type (19/64, 29.7%) and clear cell type (4/64, 6.3%). One histological subtype was not reported. In the remaining 57 patients, translocation testing could not be performed, or TFE-cytogenetics and/or immunohistochemistry results were missing. In this group, the most common RCC histological subtypes were papillary type (21/47, 44.7%) and clear cell type (11/47, 23.4%). Ten histological subtypes were not reported. Estimated 5-year (5y) EFS and 5y OS of the total group was 70.5% (95% CI = 61.7%-80.6%) and 84.5% (95% CI = 77.5%-92.2%), respectively. Estimated 5y OS for localized, regionally advanced, and metastatic disease was 96.8%, 92.3%, and 45.6%, respectively. In conclusion, the registered pediatric patients with RCC showed a reasonable outcome. Survival was substantially lower for patients with metastatic disease. This descriptive study stresses the importance of full, prospective registration including TFE-testing.

Regorafenib (R) in advanced solitary fibrous tumor (SFT): Results from an exploratory phase II clinical study

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Background: R showed antitumor activity in a PDX model of dedifferentiated SFT (D-SFT), inducing a superior tumour growth inhibition than with other antiangiogenic agents (A), such as pazopanib (P) and axitinib (A). The efficacy of P and A in patients (pts) with advanced typical- (T-)/ malignant- (M-)SFT has been already confirmed in phase 2 clinical trials, but not in D-SFT. An exploratory phase 2 study was designed to investigate the activity of R in advanced SFT. Methods: An investigator-initiated exploratory phase 2 trial was started in December 2015 at the Istituto Nazionale Tumori, Milan, Italy, to evaluate the activity of R, 160 mg OD, 3 weeks on/1 week off, until progression or limiting toxicity. in > 18 years old pts with advanced SFT. The target sample size was 16 evaluable pts; at least 3 responses were requested to reject the null hypothesis of 5% in favour of an alternative hypothesis of 30% (with type-I and type-II error rates fixed at the 10% level). Eligible pts had to have evidence of progression. Prior treatment with A was allowed. Centralized pathologic review was performed, distinguishing T-SFT, M-SFT and D-SFT subtypes. The primary end-point was the overall response rate (ORR) by Choi. Secondary end-points were ORR by RECIST, progression-free survival (PFS), overall survival (OS). Results: Enrolment was completed in February 2021. Eighteen pts were enrolled (D-SFT = 4; M-SFT = 13; T-SFT = 1). Four pts were naïve, 14 were pre-treated [12 with antiangiogenics (4 with > 1 prior antiangiogenic line); 11 with cytotoxic agents]. Three pts are ongoing, 13 completed their treatment (11 = progression, 1 = toxicity, 1 = other). Fourteen pts are evaluable for response by Choi and RECIST (1 = screening failure; 1 = early discontinuation for toxicity before radiologic assessment; 2 = too early). A definitive dose reduction was required in 5 of 14 evaluable (35.7%) pts. The ORR by Choi was 42.9% (exact binomial 95% Confidence Interval [CI]: 17.7%-71.1%), with 6/14 (42.9%) partial responses (PR), 5/14 (35.7%) stable disease (SD) and 3/14 (21.4%) progressions (PD). Best responses by RECIST were: 1/14 (7.1%) PR, 10/14 (71.4%) SD, 3/14 (21.4%) PD. 5/6 pts responsive by Choi were pre-treated with another antiangiogenic. No responses were seen in the 3 D-SFT pts. At a m-FU of 23 months, m-PFS by Choi was 3.68 (IQR: 2.73-8.54) months, with 23.4% pts progression free at 1 year. m-PFS by Choi in responsive pts was 5.62 (IQR: 2.89 – 8.54) mos. Median OS was 15.7 (IQR: 7.35-not reached) months. Conclusions: R did not show a higher activity in D-SFT compared to P and A. The response rate was in the range observed with other A, but m-PFS was shorter. This may be due to discrepancies in pt populations and a high-rate of dose reductions with R. However, responses to R were seen also in pts previously treated with other A and almost one fourth of pts benefited from R for more than a year. Clinical trial information: 2015-002629-21.

Immune contexture in high-risk soft tissue sarcomas (STS): A planned analysis of the ISG-STS-1001 randomized trial

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Background: The characteristics of immune contexture and its prognostic and predictive value in STS is left to be understood. This planned analysis of the ISG-STS-1001 trial, which compared neoadjuvant anthracycline + ifosfamide (AI) vs a histology-tailored (HT) chemotherapy (ChT), was aimed at characterizing the immune contexture after neoadjuvant ChT and investigating any association with the risk of recurrence. Methods: Patients registered in the ISG-STS-1001 study (ID: NCT01710176) were included if they had tumor tissue available for Tissue MicroArray (TMA), which was performed in the area of the surgical specimen with the highest lymphocyte infiltrate. The following markers were analyzed with IHC and measured quantitatively: CD3, CD8, PD1, GranzymeB, Foxp3, CD20, CD163, and PDL1. The T-Distributed Stochastic Neighboring Entities (t-SNE) analysis was used to account for the co-expression of IHC markers in each tumor. The prognostic value of each marker for disease-free survival (DFS) was assessed. Results: This analysis was conducted in 256 of 435 study patients. AI and HT neoadjuvant ChT did not result in any different distribution of immune contexture. Conversely, differences were observed between ‘complex’ karyotype STS (ck-STS: LMS, MPNST, UPS, MFS, pleomorphic liposarcoma, and pleomorphic rhabdomyosarcoma) and ‘simple’ karyotype STS (sk-STS: MLPS and SS). Ck-STS were enriched in both CD3+ and CD8+ cells compared to sk-STS. These cells displayed an heterogeneous distribution and were dispersed inside the tumor nest, keeping direct contact with sarcoma cells. Ck-STS also displayed an enrichment in Granzyme B+, and CD163+ cells. PDL1+ cells were occasionally identified and were more frequent in ck-STS, suggesting an immune-related expression. Most STS were negative for CD20+ cells, however, when present these cells were highly represented and organized in tertiary lymphoid-like structure. The t-SNE generated plot clustered tumors, the ‘cold’ mainly including sk-STS and the ‘hot’ mainly composed by ck-STS. In the ‘hot’ group, a cluster of tumors displayed an immune infiltrate enriched with a high number of CD3, CD8, GranzymeB, PD-1, and PDL-1+ cells. When the prognostic value of the immune markers was investigated, the presence of CD20+ cells was the only independent prognostic factor for DFS (HR=0.68, 95%CI 0.52-0.91) in a histology-stratified estimate adjusting for tumor size in cm (HR=1.07, 95%CI 1.03-1.12) and patient age (HR=1.0, 95%CI 0.97-1.02). Conclusions: Immune contexture differed across sarcoma histologies after neoadjuvant ChT, rather than across the two study arms, with ck-STS being marked by a rich immune contexture. While a CD20+ infiltrate was found to be an independent prognostic factor for a better outcome, further analyses are in progress on the prognosis of patients with the richest immune contexture. Clinical trial information: NCT01710176.

Active surveillance in primary desmoid tumor (DT): A prospective observational study

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Background: In recent years evidence of long term stabilization and spontaneous regression of primary sporadic DT resulted in a paradigm shift towards more conservative approaches. We present herein the results of an observational study aimed at prospectively assess the behavior of primary sporadic DT initially managed by active surveillance and its relation to CTNNB1 mutational status. Methods: This is an Italian prospective, multicenter, observational study (NCT 02547831) to evaluate primary sporadic DT behavior in patients (pts) >16 years with primary naive or incompletely resected and measurable disease, at any site, with CTNNB1 mutational status available. Pts were assessed by contrast enhanced MRI or CT scan at baseline, at 3, 6, 9, 12 months, then every 6 months until the third year. Tumor changes were assessed by RECIST. In case of dimensional or symptomatic progression active treatment could be proposed on an individualized basis CTNNB1 mutational status was obtained in all patients by Sanger and deep sequencing was performed in wild-type cases. Primary end-point was progression-free survival (PFS) at 3 yrs. Treatment-free survival (TFS) was also analyzed. PFS and TFS were calculated using survival analysis methods, including Kaplan-Meier plots, log-rank test for survival curves comparison, and Cox proportional-hazard multivariable regression (age, size, anatomic site and CTNNB1 mutational status). Results: From April 2013 to February 2018 108 pts were included (82% female, 18% male); median age was 39 (interquartile range, IQR 34-48) and median size 50 mm (IQR, 40-80 mm). Tumor location was: 4/108 (4%) = head&neck, 25/108 (23%) = trunk, 59/108 (55%) = abdominal wall, 3/108 (3%) = intra-abdominal, 17/108 (16%) = extremities. CTNNB1 mutations were as follow: T41A 54/108 (50%), S45F 13/108 (12%), WT 20/108 (19%), other mutations 21/108 (19%). At a m-FU of 32.3 months, the 3-year PFS was 54.5% (95% CI, 44.9%-66.1%). 42/108 (39%) pts showed a RECIST progression, with equal distribution among the different anatomic sites. None of the variables analyzed were associated to PFS. Spontaneous regression was initially observed in 27/108 (25%) patients, while it followed dimensional progression in another 33/108 (30%). 35/108 (32%) pts received active treatment, 18/42 (43%) after RECIST progression and 17/66 (26%) after symptomatic progressions. TFS at 36 months was 65.9% (95% CI, 57.3%-75.9%). S45F mutation, larger tumor size and extremity location were associated to a shorter TFS. No dimensional or symptomatic progression were observed after 36 months of FU. Conclusions: Active surveillance was marked by spontaneous regressions in 60/108 (55%) pts. An active treatment was needed in 32%. If no events occur after 3 yrs of FU, more relaxed FU schedules can be considered given the low risk of subsequent progression. Attention should be paid to patients with DT located to the extremity and/or carrying a S45F mutation. Clinical trial information: NCT 02547831.

Trabectedin (T) in desmoplastic small round cell tumor (DSRCT): Report of its effect in 3 relapsed patients (pts) and the comparison of different regimens in a patient-derived xenograft (PDX) model

e23553

Background: DSRCT is an ultra-rare soft tissue sarcoma marked by the presence of the EWS-WT1 translocation and a dismal prognosis. Anecdotal activity of T in DSRCT pts was reported. We describe herein three advanced DSRCT pts treated with T and a comparative assessment of doxorubicin (D), pazopanib (P) and T in a patient-derived xenograft (PDX) model of DSRCT. Methods: Three pts (#1, #2 and #3) suffering from progressive, metastatic, unresectable relapsing disease from a primary peritoneal DSRCT previously treated with 8 cycles of anthracycline-based neoadjuvant chemo and complete surgical resection, were started on T (1.3 mcg/sqm every 3-4 weeks). A PDX model was generated by subcutaneously implanting small tumor fragments obtained at surgery from a treatment-naïve DSRCT patient into the right flank of SCID mice. Consistency of PDX and the originating tumor was confirmed in terms of histomorphology and presence of the EWS-WT1 gene fusion. Mice were randomized to receive D, P and T, administered as single agents at optimal doses and schedules. Drug activity was assessed in terms of tumor volume inhibition (TVI) percentage in treated versus control mice. An orthotopic xenograft model was also generated by injecting DSRCT cells into the peritoneal cavity of SCID mice. Results: At the time of this report, pt #1 and #2 are on therapy with T, with a partial response by RECIST maintained after 48 and 36 months from treatment start, respectively, while #3 progressed after 4 months. In the DSRCT PDX model, T was the most effective drug, with a maximum TVI of 82%, while D and P showed lower, comparable activity (maximum TVI: 59% and 66%, respectively). In the orthotopic DSRCT PDX, DSRCT cells spreading in the abdominal cavity generated different tumor masses, properly recapitulating the dissemination pattern in patients, confirming the reliability of this preclinical model. Conclusions: Both our preliminary model and our further clinical observations support the potential of T in DSRCT. A confirmatory prospective clinical study is now warranted.

Dataset for the reporting of nephrectomy specimens for Wilms' tumour treated with preoperative chemotherapy: recommendations from the International Society of Paediatric Oncology Renal Tumour Study Group

Datasets for histopathological reporting of many cancer types are developed by the International Collaboration on Cancer Reporting (ICCR), and are used in order to ensure standardised and uniformly accepted reporting as one of the essential requirements for comparison across patient populations in evaluating and validating pathological prognostic and predictive factors. Wilms' tumours are rare, and international reporting guidelines have not yet been published by the ICCR. The assessment of Wilms' tumours differs according to the treatment approach. The Children's Oncology Group, whose approach is followed mainly in North America, advocates primary surgery, and the International Society of Paediatric Oncology Renal Tumour Study Group (SIOP-RTSG), whose approach is followed in most countries around the world, uses preoperative chemotherapy as a first step, resulting in different subclassifications, staging criteria, and histopathological prognostic factors. This dataset is developed for the countries and institutions following the SIOP-RTSG approach, and it contains core (required) and non-core (recommended) elements, based on the results of the previous SIOP-RTSG studies, which are incorporated in the latest SIOP-RTSG UMBRELLA 2016 Study protocol. The core elements include clinical information, additional specimen submitted, macroscopic tumour site and appearance, tumour focality, tumour dimensions, macroscopic extent of invasion, block identification key, histological tumour type, histological tumour grade and risk group assessment, microscopic extent of invasion, lymphovascular invasion, resection margin status, regional lymph node status, histologically confirmed distant metastases, and pathological staging (SIOP staging system). The dataset should improve communication for patient care and prognostic determination of the old and new histopathological features.

Gardner-associated fibroma of the neck: role of a multidisciplinary evaluation for familial adenomatous polyposis diagnosis

INTRODUCTION

Familial adenomatous polyposis (FAP) is a hereditary autosomal dominant disorder characterized by the development of multiple adenomas in the colon and rectum with a lifetime risk of 80%-100% to develop colorectal cancer if undetected or untreated. Gardner-associated fibroma (GAF) is a rare, benign soft tissue lesion with uncertain pathogenesis. GAF is generally associated with FAP in its clinical variant, called Gardner syndrome (GS).

CASE DESCRIPTION

A 16-year-old boy with no comorbidities and no significant medical history was referred to the Unit of Hereditary Digestive Tract Tumours, Department of Surgery, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy, for genetic counselling after surgical removal of a right anterior cervical paramedian fibroma. The histopathology on the specimen led to the diagnosis of GAF. He had no family history for colorectal cancer or gastrointestinal polyposis and denied any gastrointestinal symptoms. Physical examination showed a small frontal osteoma and colonoscopy showed the presence of multiple small sessile polyps (>100 polyps, diameter <5 mm) diffusely present on the large bowel. Genetic testing revealed a pathogenic germline variant in the APC gene. The predictive genetic test on the patient's parents and sister was negative for the identified APC mutation; therefore, the patient carried an apparent de novo germline mutation.

CONCLUSIONS

GAF may represent a sentinel sign of FAP, preceding gastrointestinal symptoms and endoscopic findings. A careful multidisciplinary approach is determinant for correct and early diagnosis of FAP.

Visceral plexiform schwannoma: A case series

Plexiform schwannoma (PS) is a benign tumour of the peripheral nerve sheath that is typically found in the skin. Fewer than 15 cases of visceral PS have been reported to date in both adults and children. We herein discuss a series of 3 patients (2 male and 1 female) with abdominal PS, aged 10-16 years (mean age, 12 years). All the patients had an acute presentation with abdominal pain, which was associated with rectal bleeding in 1 case and with walking difficulties in 1 case. Radiological investigations included abdominal magnetic resonance imaging (MRI) and computed tomography, along with neurofibromatosis screening (cerebral MRI and dermatological evaluation). Complete removal of the mass was possible in 2 of the patients (in 1 case by laparoscopically assisted surgery). Follow-up was uneventful. Abdominal PS is a rare occurrence. Due to its possible association with neurofibromatosis, the diagnosis of PS should prompt an investigation for other manifestations of this disorder.

Nivolumab and sunitinib combination in advanced soft tissue sarcomas: a multicenter, single-arm, phase Ib/II trial

BACKGROUND

Sarcomas exhibit low expression of factors related to immune response, which could explain the modest activity of PD-1 inhibitors. A potential strategy to convert a cold into an inflamed microenvironment lies on a combination therapy. As tumor angiogenesis promotes immunosuppression, we designed a phase Ib/II trial to test the double inhibition of angiogenesis (sunitinib) and PD-1/PD-L1 axis (nivolumab).

METHODS

This single-arm, phase Ib/II trial enrolled adult patients with selected subtypes of sarcoma. Phase Ib established two dose levels: level 0 with sunitinib 37.5 mg daily from day 1, plus nivolumab 3 mg/kg intravenously on day 15, and then every 2 weeks; and level -1 with sunitinib 37.5 mg on the first 14 days (induction) and then 25 mg per day plus nivolumab on the same schedule. The primary endpoint was to determine the recommended dose for phase II (phase I) and the 6-month progression-free survival rate, according to Response Evaluation Criteria in Solid Tumors 1.1 (phase II).

RESULTS

From May 2017 to April 2019, 68 patients were enrolled: 16 in phase Ib and 52 in phase II. The recommended dose of sunitinib for phase II was 37.5 mg as induction and then 25 mg in combination with nivolumab. After a median follow-up of 17 months (4-26), the 6-month progression-free survival rate was 48% (95% CI 41% to 55%). The most common grade 3-4 adverse events included transaminitis (17.3%) and neutropenia (11.5%).

CONCLUSIONS

Sunitinib plus nivolumab is an active scheme with manageable toxicity in the treatment of selected patients with advanced soft tissue sarcoma, with almost half of patients free of progression at 6 months.Trial registration number NCT03277924.

Activity of sirolimus in patients with progressive epithelioid hemangioendothelioma: A case-series analysis within the Italian Rare Cancer Network

BACKGROUND

The objective of this study was to report on a retrospective series of patients with epithelioid hemangioendothelioma (EHE) who received treatment with sirolimus within the Italian Rare Cancer Network.

METHODS

From January 2005, 38 adult patients with advanced EHE received continuous-dosing sirolimus, 5 mg daily, until they developed either toxicity or disease progression. Disease progression in the 6 months before the start of treatment was required. Each pathologic diagnosis was reviewed. The daily dose of sirolimus was adjusted based on plasma levels. Response was retrospectively assessed by local investigators using Response Evaluation Criteria in Solid Tumors, version 1.1 (RECIST). Survival was estimated using the Kaplan-Meier method.

RESULTS

All 38 patients (WW Domain Containing Transcription Regulator 1 [WWTR1]-positive, n = 37; transcription factor E3 [TFE3]-positive, n = 1) had disease progression before starting sirolimus (at baseline, 13 of 38 patients had the presence of serosal effusions and systemic symptoms). Thirty-seven patients were evaluable for response (there was 1 early interruption). The best RECIST responses were a partial response in 4 patients (10.8%), stable disease in 28 patients (75.7%), and disease progression in 5 patients (13.5%). At a 41.5-month median follow-up (interquartile range [IQR], 23.9-56.8 months), the median PFS was 13 months (95% CI, 3.7 months to not estimated [NE]), and the median OS was 18.8 months (95% CI, 10.6 months to NE). In patients who had serosal effusions at baseline, the median PFS was 4.8 months (IQR, 3.5-11.7 months), and the median OS was 10.6 months (IQR, 5.1-13.0 months), compared with 47.8 months (IQR, 11.4 months to NE) and 47.8 months (IQR, 15.7 months to NE), respectively, in patients without serosal effusions. Overall, sirolimus was fairly well tolerated, with 10 patients reporting irregular menstruation/ovary disfunction.

CONCLUSIONS

The current results confirm that sirolimus is active in EHE, leading to prolonged stabilization in most patients who present without serosal effusions. Serosal effusions are confirmed as an unfavorable prognostic sign associated with short survival, and sirolimus displays limited activity in this subgroup.

Dermatofibrosarcoma protuberans in children and adolescents: The European Paediatric Soft Tissue Sarcoma Study Group prospective trial (EpSSG NRSTS 2005)

BACKGROUND

As dermatofibrosarcoma protuberans (DFSP) are rare with no prospective series within paediatric sarcoma trials, the European Paediatric Soft Tissue Sarcoma Study Group (EpSSG) examined the clinical data and outcomes of DFSP enrolled in a multinational study of non-rhabdomyosarcoma soft tissue sarcomas (NRSTS).

PATIENTS AND METHODS

Forty-six patients with confirmed DFSP were enrolled into the EpSSG NRSTS 2005 study. All had surgical resection and none had any further therapy at diagnosis.

RESULTS

The median age at diagnosis was 6.9 years (range 0.4-17.5). All patients had localised disease, and the majority had small <5 cm tumours (93%), and 76% had Intergroup Rhabdomyosarcoma Study (IRS) I tumours. All patients had up front surgery, 32 requiring two operations. There were 11 patients with IRS II tumours, of which only two went on to have a local recurrence. After a median follow up of 49.0 months (range 4.2-130.9), all patients were alive at the time of this report, with 5-year event-free survival of 92.6% (CI 78.8-97.6) with a 100% overall survival.

CONCLUSION

This report demonstrates the ability to run prospective paediatric studies in NRSTS in multiple European countries, with reasonable numbers of DFSP patients, with few events and no deaths, and hence excellent outcomes.

Anthracycline-based and gemcitabine-based chemotherapy in the adjuvant setting for stage I uterine leiomyosarcoma: a retrospective analysis at two reference centers

Background

Radically resected early uterine leiomyosarcoma (eULMS) is still marked by a poor prognosis. Adjuvant strategies investigated up to now have not been corroborated by controlled studies. We retrospectively reviewed the clinical outcome of eULMS patients treated with adjuvant anthracycline-based or gemcitabine-based chemotherapy at two Italian reference centers.

Methods

In this explorative, retrospective, cohort analysis, we included all the consecutive patients with radically resected eULMS treated at two centers between 1997 and 2017.

Results

A total of 109 consecutive patients were included. Sixty-six (60%) received an anthracycline-based regimen, whereas 43 (40%) received a gemcitabine-based regimen. Median disease-free survival (DFS) was 41.3 months with anthracycline-based regimens compared to 20.9 months with gemcitabine-based regimens (HR: 0.49; 95% CI: 0.30–0.80; P = 0.004). In the multivariable model, anthracycline-based regimens were independently associated with a better DFS. No difference in terms of overall survival was observed.

Conclusions

DFS was not the same by using an anthracycline-based or a gemcitabine-based adjuvant chemotherapy for patients with radically resected eULMS. The results of our study are in line with recent prospective controlled evidence in limb and superficial trunk soft tissue sarcomas. The role of anthracycline-based adjuvant chemotherapy should still be viewed as a research issue in eULMS.

The Activity of Chemotherapy in Inflammatory Myofibroblastic Tumors: A Multicenter, European Retrospective Case Series Analysis

BACKGROUND

This study aimed to review the activity of cytotoxic chemotherapy in patients with inflammatory myofibroblastic tumors (IMTs) treated at nine European sarcoma reference centers.

MATERIALS AND METHODS

Patients of any age, with histologically proven IMT, treated with anthracycline-based methotrexate plus/minus vinorelbine/vinblastine (MTX-V) or other chemotherapeutic regimens between 1996 and 2018 were retrospectively reviewed. Diagnosis was confirmed at the local level by an expert pathologist. Response was retrospectively assessed by local investigators by RECIST v1.1. Progression-free survival (PFS), relapse-free survival (RFS), and overall survival (OS) were computed by Kaplan-Meier method.

RESULTS

Thirty-eight patients were included. Twenty-five patients (8 localized, 17 advanced disease) received an anthracycline-based regimen; 21 were evaluable for response. Overall response rate (ORR) was 10/21 (47.6%). At a 70.8-month median follow-up (FU), median RFS and median OS were not reached (NR) in patients with localized disease; median PFS and median OS were 6.3 (interquartile range [IQR]: 1.9-13.4) and 21.2 (IQR: 7.7-40.7) months in patients with advanced disease. Thirteen patients received MTX-V (4 localized, 9 advanced disease), all evaluable for response. ORR was 7/13 (53.8%). At a 56.6-month median FU, median RFS and median OS were 42.5 (IQR: 12.9-61.2) months and NR (no death events) in patients with localized disease, and NR (IQR: 24.9 to NR) and 83.4 months (IQR: 83.4 to NR) in patients with advanced disease. In the "other-regimens group," responses were seen in 3/4 patients treated with oral cyclophosphamide and 1/2 with docetaxel/gemcitabine.

CONCLUSION

Anthracycline-based and MTX-V regimens are very effective in IMT, with a similar ORR in both groups. MTX-V achieved a prolonged disease control. Responses were also seen with oral cyclophosphamide and docetaxel/gemcitabine, but few patients were treated with these schedules.

IMPLICATIONS FOR PRACTICE

Inflammatory myofibroblastic tumor (IMT) is an ultrarare sarcoma with known sensitivity to anaplastic lymphoma kinase (ALK) inhibitors in ALK-fused cases, although ALK inhibitors are not licensed in the disease. The current knowledge on the activity of cytotoxic chemotherapy is limited. This multi-institutional retrospective study on pediatric and adult patients with IMT shows that cytotoxic chemotherapy, and in particular anthracycline-based and methotrexate plus/minus vinorelbine/vinblastine regimens, represents a treatment option and can be considered in IMT patients irrespectively from ALK status. This study provides a benchmark for future studies on new medical therapies.

Addition of Antiestrogen Treatment in Patients with Malignant PEComa Progressing to mTOR Inhibitors

PURPOSE

Perivascular epithelioid cell tumors (PEComa) are rare mesenchymal neoplasms. mTOR inhibitors are the most active agents in PEComa and in patients progressing to mTOR inhibitors, other available therapies have limited benefit. Preclinical evidences showed a cross-talk between the mTOR pathway and estrogen receptor signaling. This provided a rationale for adding an antiestrogen treatment in female patients becoming resistant to mTOR inhibitors.

EXPERIMENTAL DESIGN

Since April 2018, female patients with advanced/metastatic PEComa progressing to mTOR inhibitors were treated with a combination of sirolimus and exemestane with or without LHRH analogue (based on menopausal status). This case series was retrospectively reviewed. Survival analyses were performed using the Kaplan-Meier method.

RESULTS

A total of seven consecutive patients treated with the combination of sirolimus and antiestrogen treatment were retrospectively reviewed. Six (86%) received a combination of sirolimus and exemestane, whereas one patient (14%) received a combination of sirolimus, exemestane, and triptorelin since in premenopausal status. After a median follow-up of 13.1 months, three patients (43%) experienced a partial response, three patients (43%) experienced a stabilization of disease, and one patient (14%) had disease progression with an overall response rate of 43% and a disease control rate of 86%.

CONCLUSIONS

In this small retrospective case series, the addition of antiestrogen treatment in female patients with advanced PEComa progressing to mTOR inhibitors resulted in a remarkable clinical benefit in a setting where no other options are available.

Precocious pseudopuberty, a paraneoplastic manifestation: a report of 2 cases

Peripheral precocious puberty (PPP) may be a paraneoplastic manifestation, associated with beta human chorionic gonadotropin (β-hCG)-secreting tumors. We describe 2 young children with β-hCG-secreting tumors presenting with signs of pubertal activation. In the first patient, a 16-month-old boy with hepatoblastoma, only initial signs of PPP at presentation were identifiable, with concomitant high levels of β-hCG. Although the tumor had good response to therapy, β-hCG levels were fluctuant until the tumor was resected surgically. The second patient, an 18-month-old boy with intracranial germ cell tumor, presented with clear signs of pubertal activation and genitalia enlargement with no initial alteration of sex hormones. In both cases, the oncologic response to therapy was good. In the first case, full remission of the pubertal signs was observed; in the second, pubertal signs were still visible 20 months after the end of treatment.

Prognostic role of MRP1 in localized high-risk soft tissue sarcoma (STS): Translational research associated to randomized phase III trial (ISG-STS 1001)

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Background: The ceiling-drug effect seen for most active drugs in STS could be related, partially, to multidrug resistance mechanisms (MDRM). We previously reported the independent prognostic role for RFS and OS of MRP1 in high-risk localized STS of limbs and trunk-wall treated with epirubicin and ifosfamide (Mol Cancer Ther.2014 13(1):249-59). A translational study was carried out within the randomized phase III trial of epirubicin plus ifosfamide vs histotype-tailored neoadjuvant chemotherapy (NCT01710176), to investigate MRP1 prognostic value using the trial population as validation set. Methods: Patients enrolled in the trial were invited to participate, through the informed consent, to this analysis. IHC used QCRL-1 (Santa Cruz biotechnology) MRP1 monoclonal antibody. TMAs were built on the highest-grade area of each tumor, being the procedure blinded for clinical data. MRP1 expression was grouped as low (≤ 25% positive cells) vs high ( > 25% positive cells) expression. For data analysis, patients were grouped as A) epirubicin plus ifosfamide control arm and B) histotype-tailored experimental arm. Drugs used in group B were: gemcitabine-docetaxel (UPS), gemcitabine-DTIC (LMS), trabectedin (High-grade (HG) myxoid LPS), ifosfamide-etoposide (MPNST) and high-dose ifosfamide (SS). Prognostic value of MRP1’s extension was analyzed using Cox’s proportional hazard regression. A p-value < 0.05 was considered statistically significant. Results: 175 patients were analyzed (median age 49; males 61%) with median follow-up of 4.66 y. Group A (n = 88) included HG-myxoid LPS (27%), SS (25%), UPS (24%), LMS (12%) MPNST (10%) and others (2%); group B (n = 87) included UPS (38%), SS (24%), HG-myxoid LPS (20%), LMS (10%) and MPNST (8%). MRP1 high extension was distributed as follows: 48% (A) and 57% (B). High MRP-1 expression showed significantly worse prognosis for disease-free survival (DFS) (HR 2.71 (1.31-5.62) p = 0.007) and a trend towards worse OS (HR = 2.75 (0.97-7.81) p = 0.058) in group A. No correlation was seen between MRP-1 expression and DFS (p = 0.384) or OS (p = 0.665), in group B. Conclusions: MRP1 overexpression was related to significant worse prognosis in 2 prospective randomized series of high-risk, localized, STS treated with neoadjuvant epirubicin and ifosfamide. These agents are both substrate of MRP1; this could add rationale for a possible predictive role, as MDRM, for the two most active drugs in STS. A trial combining epirubicin, ifosfamide and MRP1 inhibitor is currently under design.

IMMUNOSARC: a collaborative Spanish (GEIS) and Italian (ISG) sarcoma groups phase I/II trial of sunitinib and nivolumab in advanced soft tissue and bone sarcoma: Results from the phase II part, bone sarcoma cohort

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Background: Herein, we present the results of the cohort on advanced bone sarcoma patients of the phase II part of the IMMUNOSARC study (NCT03277924), a European multicentre phase I-II trial aimed at investigating the activity of the combination of sunitinib (SU) and nivolumab (NI) in selected advanced sarcoma subtypes. Methods: Adult, pre-treated, progressing patients, ECOG 0-1, with a diagnosis of osteosarcoma, high-grade bone sarcoma, Ewing sarcoma, chondrosarcoma or dedifferentiated chondrosarcoma were eligible. SU 37.5 mg/day as induction was given days 1-14 and then reduced to 25mg/day continuously. NI was administered at 3 mg/Kg every 2 weeks from week 3. SU-NI was maintained up to progression or intolerance. Primary end-point was progression-free survival rate (PFSR) at 6 months (H1: PFSR 6-months: 15%). Secondary end-points: overall survival (OS), objective response rate (ORR) by RECIST v 1.1 and toxicity. Results: From Nov 2017 to Dec 2018, 40 eligible patients were included: (M/F = 27/13), median age 47 years (range 21-74), ECOG 0 in 11 (27%) cases, 36 (90%) were metastatic, 4 (10%) locally advanced. Histology: 17 osteosarcomas (43%), 14 chondrosarcomas (35%) (4 dedifferentiated), 8 Ewing sarcomas (20%), 1 bone undifferentiated pleomorphic sarcoma (2%). PFSR at 6 months based on local evaluation was 32%. At a median FU of 12.5 months (2-26), median PFS was 3.7 months (95% IC 3.4-4) while median OS was 14.2 months (95%CI: 7.1-21.3). OS rate at 3 and 6 months were 87% and 73%, respectively. ORR by RECIST: 1 CR (2.5%) (1 patient with dedifferentiated chondrosarcoma, lasting 22 months and on going), 1 PR (2.5%) (1 patient with osteosarcoma, lasting 5.7 months), 22 SD (55%, lasting > 6 months in 45% of the cases) and 16 PD (40%). G3/5 toxicities are detailed in Table. Conclusions: The trial met its primary endpoint in the cohort of patients with advanced bone sarcoma, with > 30% of patients free from progression at 6 months. Pre-planned tumor microenvironment genomic, exploratory analysis on pre and post-treatment tumor samples is on going. Clinical trial information: NCT03277924 . [Table: see text]

Renal Tumors of Childhood-A Histopathologic Pattern-Based Diagnostic Approach

Renal tumors comprise approximately 7% of all malignant pediatric tumors. This is a highly heterogeneous group of tumors, each with its own therapeutic management, outcome, and association with germline predispositions. Histopathology is the key in establishing the correct diagnosis, and therefore pathologists with expertise in pediatric oncology are needed for dealing with these rare tumors. While each tumor shows different histologic features, they do have considerable overlap in cell type and histologic pattern, making the diagnosis difficult to establish, if based on routine histology alone. To this end, ancillary techniques, such as immunohistochemistry and molecular analysis, can be of great importance for the correct diagnosis, resulting in appropriate treatment. To use ancillary techniques cost-effectively, we propose a pattern-based approach and provide recommendations to aid in deciding which panel of antibodies, supplemented by molecular characterization of a subset of genes, are required.

Is radiotherapy required in first-line treatment of stage I diffuse anaplastic Wilms tumor? A report of SIOP-RTSG, AIEOP, JWiTS, and UKCCSG

BACKGROUND

As a significant proportion of relapses occurred in the tumor bed or abdomen on patients with the fifth National Wilms Tumor Study stage I anaplastic Wilms tumor (WT), flank radiotherapy was added for stage I anaplastic WT in the subsequent study of the Children's Oncology Group (AREN0321). Preliminary results revealed reduction of relapse rate and improved survival. In cases treated with preoperative chemotherapy, such as in International Society of Pediatric Oncology (SIOP), the value of radiotherapy has never been studied. The aim of this observational study is to describe the pattern of recurrence and survival of patients with stage I diffuse anaplastic WT (DAWT) after induction chemotherapy.

METHODS

Retrospective data analysis of the pattern of relapse and survival of all patients with stage I DAWT were included in recent SIOP, L'Associazone Italiana Ematologica Oncologia Pediatrica (AIEOP), Japan Wilms Tumor Study Group (JWiTS), United Kingdom Children's Cancer Study Group (UKCCSG) renal tumor registries. Postoperative treatment consisted of actinomycin D, vincristine, and doxorubicin for 28 weeks without local irradiation.

RESULTS

One hundred nine cases with stage I DAWT were identified, of which 95 cases received preoperative chemotherapy. Of these, seven patients underwent preoperative true-cut biopsy. Sixteen of the 95 patients relapsed (17%), six locally, four at distant site, and six combined, and all treated according to SIOP 2001 relapse protocol, which resulted in a 5-year overall survival of 93%.

CONCLUSION

Despite 13% locoregional relapse rate, an excellent rescue rate was achieved after salvage treatment, in patients with stage I DAWT whose first-line treatment comprised three-drug chemotherapy (including doxorubicin), without flank irradiation. Therefore, we continue not to advocate the use of radiotherapy in first-line treatment after preoperative chemotherapy in stage I DAWT in the next SIOP protocol.