Ocular manifestations and long-term complications of rhabdomyosarcoma in children.

BACKGROUND/OBJECTIVES: The purpose of the study was to describe the ocular manifestations of rhabdomyosarcoma in a large cohort of children. SUBJECT/METHODS: This was a retrospective observational cohort study. The medical records of all pediatric patients with head and neck rhabdomyosarcoma diagnosed between 1997 and 2021 at a tertiary-care pediatric hospital were analyzed. The main outcome measures were the incidence and prognostic role of ocular findings at presentation and long-term ocular complications. RESULTS: There were 77 children with head and neck rhabdomyosarcoma in the study cohort with 38 patients showing ocular manifestations at presentation. Median age at diagnosis was 6.0 years, the median follow-up was 5.7 years and 54.5% were male. At last follow-up, 70.1% had no evidence of progression, 26.0% were deceased, and 2.6% were on palliative treatment. Orbital signs were common (44.2%). The most common ocular findings were proptosis (18.2%), restriction of extraocular motility (28.6%), strabismus/diplopia (22.1%) and ptosis (16.9%). The most common long-term complications were bony hypoplasia/facial asymmetry (40.3%) and keratopathy/dry eye (31.2%). Poor visual acuity (≤20/200) was noted in 13 (16.9%) patients with 5 (6.5%) patients requiring an exenteration. Survival was 100% in primary orbital RMS (p = 0.02), whereas any or a combination of cranial nerve palsies carried a poor prognosis (42% survival, p = 0.008). CONCLUSIONS: In our cohort, half of children with rhabdomyosarcoma had ocular manifestations at presentation with about one-third showing orbital tumor involvement. Cranial nerve involvement carried a significantly worse prognosis for survival.

Addition of temsirolimus to chemotherapy in children, adolescents, and young adults with intermediate-risk rhabdomyosarcoma (ARST1431): a randomised, open-label, phase 3 trial from the Children's Oncology Group.

BACKGROUND: The Children's Oncology Group defines intermediate-risk rhabdomyosarcoma as unresected FOXO1 fusion-negative disease arising at an unfavourable site or non-metastatic FOXO1 fusion-positive disease. Temsirolimus in combination with chemotherapy has shown promising activity in patients with relapsed or refractory rhabdomyosarcoma. We aimed to compare event-free survival in patients with intermediate-risk rhabdomyosarcoma treated with vincristine, actinomycin, and cyclophosphamide alternating with vincristine and irinotecan (VAC/VI) combined with temsirolimus followed by maintenance therapy versus VAC/VI alone with maintenance therapy. METHODS: ARST1431 was a randomised, open-label, phase 3 trial conducted across 210 institutions in Australia, Canada, New Zealand, and the USA. Eligible patients were those aged 40 years or younger with non-metastatic FOXO1-positive rhabdomyosarcoma or unresected FOXO1-negative rhabdomyosarcoma disease from unfavourable sites. Two other groups of patients were also eligible: those who had FOXO1-negative disease at a favourable site (excluding orbit) that was unresected; and those who were aged younger than 10 years with stage IV FOXO1-negative disease with distant metastases. Eligible patients had to have a Lansky performance status score of 50 or higher if 16 years or younger and a Karnofsky performance status score of 50 or higher if older than 16 years; all patients were previously untreated. Patients were randomised (1:1) in blocks of four and stratified by histology, stage, and group. Patients received intravenous VAC/VI chemotherapy with a cyclophosphamide dose of 1·2 g/m2 per dose per cycle with or without a reducing dose of intravenous weekly temsirolimus starting at 15 mg/m2 or 0·5 mg/kg per dose for those who weighed less than 10 kg. The total duration of therapy was 42 weeks followed by 6 months of maintenance therapy with oral cyclophosphamide plus intravenous vinorelbine for all patients. Temsirolimus was withheld during radiotherapy and for 2 weeks before any major surgical procedure. The primary endpoint was 3-year event-free survival. Data were analysed with a revised intention-to-treat approach. The study is registered with ClinicalTrials.gov (NCT02567435) and is complete. FINDINGS: Between May 23, 2016, and Jan 1, 2022, 325 patients were enrolled. In 297 evaluable patients (148 assigned to VAC/VI alone and 149 assigned to VAC/VI with temsirolimus), the median age was 6·3 years (IQR 3·0-11·3); 33 (11%) patients were aged 18 years or older; 179 (60%) of 297 were male. 113 (77%) of 148 patients were FOXO1 negative in the VAC/VI group, and 108 (73%) of 149 were FOXO1 negative in the VAC/VI with temsirolimus group. With a median follow-up of 3·6 years (IQR 2·8-4·5), 3-year event-free survival did not differ significantly between the two groups (64·8% [95% CI 55·5-74·1] in the VAC/VI group vs 66·8% [57·5-76·2] in the VAC/VI plus temsirolimus group (hazard ratio 0·86 [95% CI 0·58-1·26]; log-rank p=0·44). The most common grade 3-4 adverse events were anaemia (62 events in 60 [41%] of 148 patients in the VAC/VI group vs 89 events in 87 [58%] of 149 patients in the VAC/VI with temsirolimus group), lymphopenia (83 events in 65 [44%] vs 99 events in 71 [48%]), neutropenia (160 events in 99 [67%] vs 164 events in 105 [70%]), and leukopenia (121 events in 86 [58%] vs 132 events in 93 [62%]). There was one treatment-related death in the VAC/VI with temsirolimus group, categorised as not otherwise specified. INTERPRETATION: Addition of temsirolimus to VAC/VI did not improve event-free survival in patients with intermediate-risk rhabdomyosarcoma defined by their FOXO1 translocation status and clinical factors. Novel biology-based strategies are needed to improve outcomes in this population. FUNDING: The Children's Oncology Group (supported by the US National Cancer Institute, US National Institutes of Health).

Safety and Preliminary Efficacy of Once-Weekly Split-Dose Selinexor in Soft Tissue Sarcoma: Results of the Phase Ib METSSAR Clinical Trial.

BACKGROUND: The approved dose of Selinexor, 60 mg twice-weekly, is associated with several clinically relevant toxicities. Preclinical studies show that a sustained-release formulation of selinexor results in a lower toxicity profile. OBJECTIVE: The phase 1b METSSAR trial assessed the safety and tolerability of an alternative dosing schedule of selinexor (to mimic the sustained-release formulation) in advanced soft tissue sarcoma (STS) patients. PATIENTS AND METHODS: Selinexor was administered in a split-dose schedule (40 mg, 20 mg, 20 mg in the morning, afternoon, and evening, respectively) on days 1, 8, 15, and 22 of a 28-day cycle, until unacceptable toxicity or disease progression. The primary endpoint was the rate of grade ≥ 3 treatment-related adverse events (TRAEs). Secondary objectives were EORTC QLQ-C30 quality of life (QoL) assessment, and preliminary efficacy. RESULTS: Twenty patients with 12 STS subtypes were enrolled and received a median of four cycles of treatment. There were no grade ≥ 3 TRAEs. Dysgeusia, nausea, fatigue, and thrombocytopenia were the most common grade ≤ 2 TRAEs. No treatments were discontinued due to TRAE, but four patients (20%) required dose reduction. Median change in global health status (GHS) score from baseline to cycle 2 (by QLQ-C30 v3.0) was - 8.33, and only 39% of patients reported a clinically meaningful decline in GHS score (≥ 10 points). Median symptom scale scores on treatment were increased for fatigue (+12.35), nausea/vomiting (+18.52), and anorexia (+16.67), but reduced for pain (- 3.70). The median progression-free survival (PFS) was 4.0 months (95% confidence interval 1.9-7.5). CONCLUSIONS: Split-dose once-weekly selinexor was reasonably well tolerated in this heterogeneous group of advanced STS patients with a better, or at least similar, clinician- and patient-reported toxicity profile compared to the standard dosing regimen. Further clinical evaluation is warranted, as better dose delivery can lead to improved antitumor efficacy.

Real-word experience of pazopanib and sorafenib in patients with desmoid tumors: A CanSaRCC multi-center study.

BACKGROUND: Sorafenib and pazopanib, two tyrosine kinase inhibitors (TKI), are widely used in patients with progressive symptomatic desmoid tumors (DT). Limited real-word data is available on long-term outcomes of patients who progressed on, stopped, or continued TKIs. METHODS: Patients diagnosed with DTs and treated with sorafenib or pazopanib between 2011 and 2022 at 11 institutions were reviewed. Patient history, response to therapy and toxicity were recorded. Statistical analyses utilized Kaplan-Meier and log-rank tests. RESULTS: 142 patients with DT treated with sorafenib (n = 126, 88.7 %) or pazopanib (n = 16, 11.3 %) were analyzed. The median treatment duration was 10.8 months (range: 0.07- 73.9). The overall response rate and the disease control rate were 26.0 % and 95.1 %, respectively. The median tumor shrinkage was - 8.5 % (range -100.0 %- +72.5 %). Among responders, the median time to an objective response was 15.2 months (range: 1.1 to 33.1). The 1-year and 2-year progression-free survival rates were 82 % and 80 %. Dose reductions were necessary in 34 (23.9 %) patients. Grade 3 or higher adverse events were reported in 36 (25.4 %) patients. On the last follow-up, 55 (38.7 %) patients continued treatment. Treatment discontinuation (n = 85, 59.9 %) was mainly for toxicity (n = 35, 45.9 %) or radiological or clinical progression (n = 30, 35.3 %). For the entire cohort, 36 (25.4 %) patients required subsequent treatment. In the 32 responders, only 1 (3.1 %) patient required a subsequent treatment. In patients who discontinued TKI, 25 (44.6 %) with stable disease received subsequent treatment compared to 0 (0.0 %) of responders. CONCLUSION: This retrospective study represents the largest cohort of DT patients treated with sorafenib or pazopanib to date. Discontinuation of treatment in responders is safe. The optimal treatment duration in patients with stable disease remains to be defined.

Adapting an Adolescent and Young Adult Program Housed in a Quaternary Cancer Centre to a Regional Cancer Centre: Creating Equitable Access to Developmentally Tailored Support.

Adolescents and young adults (AYAs) with cancer, representing those between 15 and 39 years of age, face distinctive challenges balancing their life stage with the physical, emotional, and social impacts of a cancer diagnosis. These challenges include fertility concerns, disruptions to educational and occupational pursuits, issues related to body image and sexual health, and the need for age-appropriate psychosocial support within their communities. The Princess Margaret Cancer Centre (PM), a quaternary care center, established a specialized AYA program in 2014, offering holistic and developmentally tailored psychosocial support and currently, efforts are underway to expand this to other regions in the province to address the need for equitable access. The establishment process involves securing funding, conducting an environmental scan, identifying service gaps, developing clinical pathways, and implementing AYA supportive care. An accessible AYA program should also consider social determinants of health, social location, intersectionality, and an interdisciplinary health approach in understanding health inequities in AYA oncology care. This paper describes the processes implemented and challenges faced in creating a community-based AYA program beyond major resource-rich cities and efforts to address intersectionality.

Parental Involvement in the Transition from Paediatric to Adult Care for Youth with Chronic Illness: A Scoping Review of the North American Literature.

With medical advancements and improvements in medical technology, an increasing number of children with chronic conditions survive into adulthood. There is accordant growing interest toward supporting adolescents throughout the transition from paediatric to adult care. However, there is currently a paucity of research focusing on the role that these patients' parents should play during and after the transition to adult care and if maintained parental involvement is beneficial during this transition within a North American context. Accordingly, this scoping review utilized Arksey and O'Malley's five-step framework to consider parental roles during chronically ill children's transition to adult care. APA PsycInfo, CINAHL, EMBASE, MEDLINE, ProQuest, and Scopus were searched alongside advanced Google searches. Thematic content analysis was conducted on 30 articles meeting the following inclusion criteria: (1) published in English between 2010 and 2022, (2) conducted in Canada or the United States, (3) considered adolescents with chronic conditions transitioning to adult care, (4) family being noted in the title or abstract, and (5) patient populations of study not being defined by delays in cognitive development, nor mental illness. Three themes emerged from the literature: the impacts of maintaining parental involvement during transition to adult care for patients, parents experiencing feeling loss of stability and support surrounding the transition of their child's care, and significant nonmedical life events occurring for youths at the time of transition of care. Parents assuming supportive roles which change alongside their maturing child's needs were reported as being beneficial to young peoples' transition processes, while parents who hover over or micromanage their children during this time were found to hinder successful transitions. Ultimately, the majority of reviewed articles emphasized maintained parental involvement as having a net positive impact on adolescents' transitions to adult care. As such, practice and policies should be structured to engage parents throughout the transition process to best support their chronically ill children during this time of change.

A comparison of the sociodemographic, medical, and psychosocial characteristics of adolescents and young adults diagnosed with cancer recruited in-person and online: A Canadian cross-sectional survey.

Introduction: Adolescents and young adults diagnosed with cancer (AYAs) are under-represented in research. The Internet and social media could increase the reach of recruitment efforts but may impact sample characteristics. This study evaluated the characteristics of AYAs recruited in-person at an urban hospital versus the Internet in terms of their sociodemographic and medical characteristics, and psychosocial wellbeing, and offers recommendation for increasing the inclusivity and representativeness of research samples. Methods: Participant data from a cross-sectional survey of AYAs in Canada were evaluated. In-person hospital recruitment used a registry to identify patients attending ambulatory clinics. Internet recruitment included notices on hospital, team members', and community partners' social media channels, and email newsletters. Independent sample t-tests and Chi-squared tests were used to identify differences in participant sociodemographic, medical, and psychosocial characteristics based on recruitment source. Results: Of 436 participants, 217 (49.8%) were recruited in-person and 219 (50.2%) online. Online participants were more likely: to be white (p < .001), women (p < .001), and Canadian-born (p < .001); to speak English at home (p < .001), live alone (p = .001) and live in rural settings (p = .014); and to be farther from diagnosis (p = .023), diagnosed with breast cancer (p < .001), and cancer free (p < .001) compared to the hospital sample. Online participants also reported higher anxiety, depression, and loneliness (p < .001), and lower social support (p < .001), self-efficacy for coping with cancer (p < .001), and life satisfaction (p = .006). Conclusions: Online recruitment yielded a more geographically diverse but less sociodemographically diverse sample of AYAs who were farther from diagnosis and had poorer psychosocial wellbeing than in-person recruitment at an urban hospital. Future research efforts should consider partnering with under-represented communities and using targeted and stratified online and in-person recruitment strategies to achieve an inclusive and representative sample of AYAs.

Clinico-demographic characteristics and outcomes of radiation-induced sarcomas (RIS): a CanSaRCC study.

Background: Radiation-induced sarcomas (RIS) tend to have aggressive behaviour and because of their rarity, the most appropriate management for these malignancies is uncertain. Objectives: Using the Canadian Sarcoma Research and Clinical Collaboration (CanSaRCC) database, a national sarcoma registry, we aimed to investigate prognostic factors and outcomes for RIS. Design: Retrospective study of RIS patients treated from 1996 to 2021 at three Canadian centres. Methods: RIS was defined as a sarcoma arising in a previously irradiated field following a 3+ year latency period, whose histology was distinct from the initially irradiated tumour. Clinicopathologic and treatment-related information was extracted from the CanSaRCC database. Overall survival (OS) was defined as the time from RIS diagnosis to death from any cause. Response rate (RR) to neoadjuvant chemotherapy (NACT) was based on physician assessment. Time-to-event analyses were estimated using the Kaplan-Meier method, with Cox regression for multivariate analysis. We considered a two-tailed p-value of <0.05 as statistically significant. Results: One hundred seven tumours met the criteria for RIS and were divided into three subgroups: breast angiosarcoma (BAS, n = 54), osteosarcoma (OST, n = 16), and other soft-tissue sarcomas (STS, n = 37). Patients were mostly female (n = 85, 79%), treated initially for breast carcinomas (n = 54, 50.5%), and diagnosed with high-grade tumours (n = 61/71, 86%). None had evidence of synchronous metastasis. Patients with OST were younger (median age: 48 years, p < 0.001), and BAS had the shortest latency interval (8 versus 18 years for OST/STS, p < 0.001). Most patients underwent surgery, 76% (n = 76/100) R0; 24% (n = 26) received radiation therapy, mostly (n = 15, 57.7%) neoadjuvant. Among those receiving chemotherapy, 30 (75%) underwent NACT; among patients with documented response assessment, the RR was 68% (n = 17/25), being even higher in the BAS population (89.5%, n = 13/17). Median OS was 53 months (95% CI 34-101), with a 5-year OS of 47.6%; larger tumour size, high histologic grade and older age were independent prognostic factors for worse OS. Conclusion: Surgery is standard, and NACT might be useful to downsize large lesions, especially in BAS patients. Raising RIS awareness is fundamental to promoting appropriate management and fostering research through multi-institutional collaborations.

Real-world experience of tyrosine kinase inhibitors in children, adolescents and adults with relapsed or refractory bone tumours: A Canadian Sarcoma Research and Clinical Collaboration (CanSaRCC) study.

OBJECTIVES: We conducted a retrospective multi-centre study to assess the real-world outcome of regorafenib (REGO) and cabozantinib (CABO) in recurrent/refractory bone tumours (BTs) including osteosarcoma (OST), Ewing sarcoma (EWS) and chondrosarcoma (CS)/extra-skeletal mesenchymal CS (ESMC). METHODS: After regulatory approval, data from patients with recurrent BT (11 institutions) were extracted from CanSaRCC (Canadian Sarcoma Research and Clinical Collaboration) database. Patient characteristics, treatment and outcomes were collected. Progression-free survival (PFS) and overall survival (OS) were estimated using the Kaplan-Meier method. RESULTS: From July 2018 to May 2022, 66 patients received REGO or CABO; 39 OST, 18 EWS, 4 CS and 5 ESMC. Median age was 27.8 years (range 12-76); median starting dose was 60 mg for CABO (n = 37, range 40-60) and 120 mg for REGO (n = 29, range 40-160). Twenty-eight (42.4%) patients required dose reduction: hand-foot syndrome 7 (10.6%), nausea/vomiting 1 (1.5%), diarrhoea 1 (1.5%), 2 elevated LFTs (3%), elevated bilirubin 1 (1.5%) and mucositis 1 (1.5%). The median OS for patients with OST, EWS, CS and ESMC was 8.5 months (n = 39, 95% CI 7-13.1); 13.4 months (n = 18, 95% CI 3.4-27.2), 8.1 (n = 4, 95% CI 4.1-9.3) and 18.2 (n = 5, 95% CI (10.4-na), respectively. Median PFS for OST, EWS, CS and ECMS was 3.5 (n = 39, 95% CI 2.8-5), 3.9 (n = 18, 95% CI 2.1-5.9), 5.53 (n = 4. 95% CI 2.13-NA) and 11.4 (n = 5, 95% CI 1.83-14.7), respectively. Age, line of therapy, REGO versus CABO, or time from diagnosis to initiation of TKI were not associated with PFS on univariable analysis. CONCLUSION: Our real-world data show that TKIs have meaningful activity in recurrent BT with acceptable toxicities when started at modified dosing. Inclusion of TKIs in earlier lines of treatment and/or maintenance therapy could be questions for future research.

Primitive Myxoid Mesenchymal Tumor of Infancy With Brain Metastasis Case Report and Literature Review.

Primitive myxoid mesenchymal tumor of infancy (PMMTI), a rare soft tissue tumor with distinct characteristics. PMMTI tends to have an aggressive local course, with multiple relapses and poor response to treatment. Rare cases of distant metastases have been described before. We described the second case of PMMTI with brain metastasis.

Safety, Immunologic, and Clinical Activity of Durvalumab in Combination with Olaparib or Cediranib in Advanced Leiomyosarcoma: Results of the DAPPER Clinical Trial.

PURPOSE: Non-inflamed (cold) tumors such as leiomyosarcoma do not benefit from immune checkpoint blockade (ICB) monotherapy. Combining ICB with angiogenesis or PARP inhibitors may increase tumor immunogenicity by altering the immune cell composition of the tumor microenvironment (TME). The DAPPER phase II study evaluated the safety, immunologic, and clinical activity of ICB-based combinations in pretreated patients with leiomyosarcoma. PATIENTS AND METHODS: Patients were randomized to receive durvalumab 1,500 mg IV every 4 weeks with either olaparib 300 mg twice a day orally (Arm A) or cediranib 20 mg every day orally 5 days/week (Arm B) until unacceptable toxicity or disease progression. Paired tumor biopsies, serial radiologic assessments and stool collections were performed. Primary endpoints were safety and immune cell changes in the TME. Objective responses and survival were correlated with transcriptomic, radiomic, and microbiome parameters. RESULTS: Among 30 heavily pretreated patients (15 on each arm), grade ≥ 3 toxicity occurred in 3 (20%) and 2 (13%) on Arms A and B, respectively. On Arm A, 1 patient achieved partial response (PR) with increase in CD8 T cells and macrophages in the TME during treatment, while 4 had stable disease (SD) ≥ 6 months. No patients on Arm B achieved PR or SD ≥ 6 months. Transcriptome analysis showed that baseline M1-macrophage and B-cell activity were associated with overall survival. CONCLUSIONS: Durvalumab plus olaparib increased immune cell infiltration of TME with clinical benefit in some patients with leiomyosarcoma. Baseline M1-macrophage and B-cell activity may identify patients with leiomyosarcoma with favorable outcomes on immunotherapy and should be further evaluated.

Common queries in managing rhabdomyosarcoma in low- and middle-income countries: An Indo-North American collaboration.

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma among children and adolescents. The management of RMS involves risk stratification of the patients based on various clinicopathological characteristics. The multimodality treatment approach requires chemotherapy, surgery, and/or radiation. The treatment of RMS necessitates the involvement of multiple disciplines, such as pathology, pediatric oncology, surgery, and radiation oncology. The disease heterogeneity, molecular testing, evolving treatment regimens, and limited resources are some of the challenges faced by clinicians while treating a patient with RMS in low- and middle-income countries (LMICs). In this review, we endeavor to bring experts from varying fields to address clinicians' common questions while managing a child or adolescent with RMS in LMICs. This review is most applicable to level 2 centers in LMICs as per the levels of services described by the Adapted Treatment Regimens Working Group of the Pediatric Oncology in Developing Countries committee of the International Society of Pediatric Oncology.

The impact of surgical resection margins on outcomes for adults with head and neck osteosarcomas: A Canadian sarcoma research and Clinical Collaboration (CanSaRCC) study.

OBJECTIVE: The aim of the study is to describe the factors that influence outcome in adults with head and neck osteosarcoma (HNO) with a specific focus on the margin status. METHODS: Patients with a diagnosis of HNO between the years 1996-2021 were reviewed from the Canadian Sarcoma Research and Clinical Collaboration (CanSaRCC) Database. Baseline characteristics, pathology, treatment, and outcomes were analyzed. Univariable (UVA) and multivariable (MVA) Cox regression models were performed. 5-year locoregional control rate and overall survival (OS) were estimated using Kaplan-Meier method and Log-Rank test. RESULTS: Of 50 patients with a median age of 40 years (range 16-80), 27 (54%) were male. HNO commonly involved the mandible (n = 21, 42%) followed by maxilla (n = 15, 30%). Thirteen (33.3%) had low-intermediate grade and 26 (66.6%) had high grade tumors. Three patients (6%) had negative resection margins (>5 mm), 24 (48%) had close margins (1-5 mm), 15 (30%) had positive margins (<1mm) and 7 (16%) had unknown margin status. In total, 39 (78%) received chemotherapy - 22 (44%) received neoadjuvant chemotherapy while 17 (34%) received adjuvant chemotherapy. A total of 12 (24%) patients received radiotherapy, of whom 8 (16%) had adjuvant and 3 (6%) had neo-adjuvant. Median follow-up time was 6.3 years (range 0.26-24.9). Disease recurred in 21 patients (42%), of whom 15 (30%) had local recurrence only, 4 (8%) had distant metastasis, and 2 (4%) had both local and distant recurrence. 5-year locoregional control rate and OS was 62% and 79.2% respectively. Resection margins <3 mm was associated with lower 5 years OS and locoregional control rate (Log-Rank p = 0.02, p = 0.01 respectively). CONCLUSION: Osteosarcomas of the head and neck are rare and local recurrence remains a concern. Surgical resection with negative resection margins may improve survival, and a 3 mm resection margin threshold may optimize survival. Radiotherapy and/or chemotherapy should be considered in a multidisciplinary setting based on risk-features.

Feasibility of combining temsirolimus to vincristine, dactinomycin, cyclophosphamide, and vincristine and irinotecan chemotherapy for children with intermediate-risk rhabdomyosarcoma: A report from Children's Oncology Group.

BACKGROUND: Temsirolimus has shown in vivo activity against rhabdomyosarcoma (RMS). We aimed to determine the feasibility of incorporating temsirolimus within the standard Children's Oncology Group (COG) chemotherapy backbone of vincristine, actinomycin-D, and cyclophosphamide (VAC) alternating with vincristine and irinotecan (VI) in children with intermediate-risk (IR) RMS. METHODS: The feasibility phase of the COG IR-RMS trial, ARST1431 (NCT02567435), assigned 10 patients to receive 15 mg/m2 /dose (dose level 1) of temsirolimus on days 1, 8, and 15 of each of three weekly VAC and VI cycles for the first 12 weeks of induction chemotherapy. The primary endpoint of the feasibility phase was to establish the safe dose and safety of combining temsirolimus with VAC/VI. The combination regimen was deemed feasible if less than 40% of patients developed a priori defined nonhematological dose-limiting toxicities (DLTs). RESULTS: Ten patients (seven males and three females; median age = 4.5 years [range: 0.2-14.4 years]) with IR-RMS were enrolled and received dose level 1 of temsirolimus. Eight patients had FOXO1-negative disease, while two had FOXO1-positive disease. Two patients had metastatic disease. Of 10 patients, two developed DLTs: grade 3 oral mucositis and pneumonitis. Four patients (40%) had grade 4 neutropenia. No treatment-related mortality occurred. The median duration of the completion of the feasibility phase was 12.1 weeks (range: 11.7-15 weeks). CONCLUSIONS: Weekly temsirolimus at 15 mg/m2 /dose during VAC/VI chemotherapy was feasible and well tolerated. The efficacy of this regimen is currently being tested in a phase III randomized trial against VAC/VI chemotherapy alone in the ARST1431 trial.

Desmoid Tumors in Familial Adenomatous Polyposis Patients: Favorable Outcomes with Multidisciplinary Management.

OBJECTIVE: In this study, we aimed to describe the clinical features, management, and outcomes of desmoid tumors (DTs) in familial adenomatous polyposis (FAP) patients at a high-volume sarcoma center. METHODS: Consecutive patients with FAP and DTs were identified from our institutional databases (1985-2021). Patient demographics, treatment, and outcomes were described. Categorical data were compared using Fisher's exact test, and Kaplan-Meier curves were used to estimate progression-free survival (PFS). RESULTS: Forty-five patients with 67 DTs were identified: 39 mesenteric or retroperitoneal (58.2%), 17 abdominal wall (25.4%), 4 extremity (6%), 4 breast (6%) and 3 back (4.4%). Severe DT symptoms were present in 12 patients (26.7%). Initial treatments per tumor were observation in 30 (44.8%) DTs, chemotherapy in 15 (22.4%) DTs, surgery in 10 (14.9%) DTs, and other systemic therapies in 10 (14.9%) DTs. The majority of DTs remained stable with observation or a single intervention (77.8%). Median PFS was 23.4 years (95% confidence interval 7.6-39.2). In the 12 severely symptomatic patients, four patients required more than two interventions for DT control. At a median follow-up of 6.0 years (range 0.7-35.8 years), 33 (73.3%) patients were alive with disease, 7 (15.6%) were alive without disease, and 5 (11.1%) died of other causes. No patients died of DT-related complications. CONCLUSIONS: The majority of DTs in FAP patients remained stable with observation or a single intervention. There were no DT-related deaths; however, 12 of 45 patients (26.7%) experienced significant tumor morbidity and required more interventions for disease control. Further studies on quality of life are required.

Radiation-induced sarcomas following childhood cancer - A Canadian Sarcoma Research and Clinical Collaboration Study (CanSaRCC).

BACKGROUND: Radiation-induced sarcoma (RIS) is a late toxicity of radiation therapy (RT) usually associated with poor prognosis. Due to ongoing improvements in childhood cancer treatment and patient outcomes, RIS may become more prevalent notwithstanding evolving indications for RT. Due to limited reported studies, we sought to review our experience with RIS in survivors of pediatric cancer. METHODOLOGY: Data were collected on RIS patients following treatment for childhood cancer (initial diagnosis <18 years) identified in the CanSaRCC database. Additionally, details on the protocol guidance at time of treatment were compared with current guidelines for the same disease. RESULTS: Among 12 RIS identified, median age at initial diagnosis was 3.5 years (range 0.16-14) and the latency from RT to RIS diagnosis was 24.5 (range 5.4-46.2) years. Initial diagnoses included neuroblastoma, rhabdomyosarcoma, Ewing sarcoma, Wilms tumor, retinoblastoma and Hodgkin's Lymphoma. RIS histologies included osteosarcoma and soft tissue sarcomas. In comparison to protocols followed at time of diagnosis to current ones (2022), 7/12 (58%) patients would have required RT. RIS treatment included chemotherapy, radiation and surgery in 3/11 (27%), 10/11 (90%), and 7/11 (63%) patients, respectively. With a median follow-up time of 4.7 years from diagnosis of RIS, 8 (66%) patients were alive and 4 (33%) had died of progressive RIS. CONCLUSION: RIS is a serious late effect of radiotherapy in childhood cancer; however, radiation remains an integral component of primary tumor management and requires participation from a specialized multi-disciplinary team, aiming to mitigate RIS and other potential late effects.

Retrospective observational studies in ultra-rare sarcomas: A consensus paper from the Connective Tissue Oncology Society (CTOS) community of experts on the minimum requirements for the evaluation of activity of systemic treatments.

BACKGROUND: In ultra-rare sarcomas (URS) the conduction of prospective, randomized trials is challenging. Data from retrospective observational studies (ROS) may represent the best evidence available. ROS implicit limitations led to poor acceptance by the scientific community and regulatory authorities. In this context, an expert panel from the Connective Tissue Oncology Society (CTOS), agreed on the need to establish a set of minimum requirements for conducting high-quality ROS on the activity of systemic therapies in URS. METHODS: Representatives from > 25 worldwide sarcoma reference centres met in November 2020 and identified a list of topics summarizing the main issues encountered in ROS on URS. An online survey on these topics was distributed to the panel; results were summarized by descriptive statistics and discussed during a second meeting (November 2021). RESULTS: Topics identified by the panel included the use of ROS results as external control data, the criteria for contributing centers selection, modalities for ensuring a correct pathological diagnosis and radiologic assessment, consistency of surveillance policies across centers, study end-points, risk of data duplication, results publication. Based on the answers to the survey (55 of 62 invited experts) and discussion the panel agreed on 18 statements summarizing principles of recommended practice. CONCLUSIONS: These recommendations will be disseminated by CTOS across the sarcoma community and incorporated in future ROS on URS, to maximize their quality and favor their use as control data when results from prospective studies are unavailable. These recommendations could help the optimal conduction of ROS also in other rare tumors.