Local treatment in initially unresected non-rhabdomyosarcoma soft-tissue sarcomas of children and adolescents: A retrospective single-center experience

BACKGROUND

Pediatric non-rhabdomyosarcoma soft-tissue sarcomas (NRSTS) are a heterogeneous group of aggressive tumors. Patients with locally advanced/initially unresected disease represent a subset of patients with unsatisfactory outcome: limited data are available on the best treatment approach, in particular regarding local therapy.

METHODS

This retrospective analysis concerned 71 patients < 21 years old with nonmetastatic, initially unresected adult-type NRSTS, treated at a referral center for pediatric sarcomas from 1990 to 2021. Patients were treated using a multimodal approach, based on the protocols adopted at the time of their diagnosis.

RESULTS

The series included a selected group of patients with unfavorable clinical characteristics, i.e., most cases had high-grade and large tumors, arising from axial sites in 61% of cases. All patients received neoadjuvant chemotherapy, 58 (82%) had delayed surgery (R0 in 45 cases), and 50 (70%) had radiotherapy. Partial response to chemotherapy was observed in 46% of cases. With a median follow-up of 152 months (range, 18-233), 5-year event-free survival (EFS) and overall survival (OS) were 39.9% and 56.5%, respectively. Survival was significantly better for patients who responded to chemotherapy, and those who had a delayed R0 resection. Local relapse at 5 years was 7.7% for patients who did not undergo delayed surgery.

CONCLUSIONS

Our series underscores the unsatisfactory outcome of initially unresected NRSTS patients. Improving the outcome of this patient category requires therapeutic strategies able to combine novel effective systemic therapies with a better-defined local treatment approach to offer patients the best chances to have R0 surgery.

Palliative sedation in paediatric solid tumour patients: choosing the best drugs

OBJECTIVES

Cancer remains the leading cause of mortality by disease in childhood in high-income countries. For terminally ill children, care focuses on quality of life, and patient management fundamentally affects grieving families. This paper describes our experience of palliative sedation (PS) for children with refractory symptoms caused by solid tumours, focusing on the drugs involved.

METHODS

We retrospectively collected data on all children treated for cancer who died at the pediatric oncology unit of the Fondazione IRCCS Istituto Nazionale dei Tumori between January 2016 and December 2020.

RESULTS

Of the 29 patients eligible for the study, all but 4 received PS. Midazolam was always used, combined in 16 cases with other drugs (mainly classic neuroleptics, alpha-2 agonists and antihistamines). Throughout the period of PS and on the day of death, patients with sarcoma were given higher doses of midazolam and morphine, and more often received combinations of drugs than patients with brain tumours. Sarcoma causes significant symptoms, while brain tumours require less intensive analgesic-sedative therapies because they already impair a patient's state of consciousness.

CONCLUSIONS

Optimising pharmacological treatments demands a medical team that knows how drugs (often developed for other indications) work. Emotional and relational aspects are important too, and any action to lower a patient's consciousness should be explained to the family and justified. Parents should not feel like helpless witnesses. Guidelines on PS in paediatrics could help, providing they acknowledge that a child's death is always a unique case.

End-of-Life transfusion support at hospice and pediatric oncology unit: Bridging the gap between benefits and therapeutic alliance

OBJECTIVES

Although transfusion support is commonly used in oncological palliative care, there is still a paucity of literature. We examined the transfusion support provided in the terminal stage of the disease and compared the approach at a pediatric oncology unit and a pediatric hospice.

CASE DESCRIPTION

This case series analyzed patients treated at the Fondazione IRCCS Istituto Nazionale dei Tumori di Milano (INT)'s pediatric oncology unit who died between January 2018 and April 2022. We compared these with those who died at the VIDAS hospice and analyzed the number of complete blood counts taken in a patient's last 14 days of life, and the number of transfusions performed in the same period.We analyzed 44 patients (22 in pediatric oncology unit; 22 in hospice) in total. Twenty-eight complete blood counts were performed (7/22 patients at the hospice; 21/22 patients at the pediatric oncology unit). Nine patients were given transfusions, three at the hospice, six at our pediatric oncology unit (24 transfusions in total): 20 transfusions at the pediatric oncology unit, four at the hospice. In total 17/44 patients were given active therapies in the last 14 days of life: 13 at the pediatric oncology unit, four at the pediatric hospice. Ongoing cancer treatments did not correlate with a greater likelihood of receiving a transfusion (p=0.91).

CONCLUSIONS

The hospice's approach was more conservative than the pediatric oncology one. In the in-hospital setting, the need for a transfusion cannot always be decided on by a combination of numerical values and parameters alone. The family's emotional-relational response must be considered too.

Treatment at Relapse for Synovial Sarcoma of Children, Adolescents and Young Adults: From the State of Art to Future Clinical Perspectives

While the overall prognosis is generally quite satisfactory in children, adolescents and young adults with localised synovial sarcoma at first diagnosis, the outcome remains poor for patients after relapse. Conversely to the front-line standardised treatment options, patients with relapse generally have an individualised approach and to date, there is still a lack of consensus regarding standard treatment approaches. Studies on relapsed synovial sarcoma were able to identify some prognostic variables that influence post-relapse survival, in order to plan risk-adapted salvage protocols. Treatment proposals must consider previous first-line treatments, potential toxicities, and the possibility of achieving an adequate local treatment by new surgery and/or re-irradiation. Effective second-line drug therapies are urgently needed. Notably, experimental treatments such as adoptive engineered TCR-T cell immunotherapy seem promising in adults and are currently under validation also in paediatric patients.

Clinical Insight on Proton Therapy for Paediatric Rhabdomyosarcoma

This paper offers an insight into the use of Proton Beam Therapy (PBT) in paediatric patients with rhabdomyosarcoma (RMS). This paper provides a comprehensive analysis of the literature, investigating comparative photon-proton dosimetry, outcome, and toxicity. In the complex and multimodal scenario of the treatment of RMS, clear evidence of the therapeutic superiority of PBT compared to other modern photon techniques has not yet been demonstrated; however, PBT can be considered an excellent treatment option, in particular for young children and patients with specific primary sites, such as the head and neck area (and especially the parameningeal regions), genito-urinary, pelvic, and paravertebral regions. The unique depth-dose characteristics of protons can be exploited to achieve significant reductions in normal tissue doses and may allow an escalation of tumour doses and greater sparing of normal tissues, thus potentially improving local control while at the same time reducing toxicity and improving quality of life. However, access of children with RMS (and more in general with solid tumors) to PBT remains a challenge, due to the limited number of available proton therapy installations.

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.

Management and pharmacotherapy of pediatric colorectal carcinoma: a review

INTRODUCTION

Colorectal carcinoma (CRC) is one of the most common tumors in adult, but is extremely rare in children. In childhood, CRC often presents unfavorable aggressive histotypes, advanced clinical stage at onset and a worse prognosis. Pediatric CRC series are limited and include few patients, therefore information about treatment strategy and pharmacotherapy is scarce. For this reason, management of these patients represents a real challenge for pediatric oncologists.

AREAS COVERED

The authors provide an overview of the general features and management strategies of pediatric CRC with specific attention to systemic treatment. Literature data regarding pharmacotherapy in published pediatric series are summarized and analyzed in detail, according to adult treatment standards.

EXPERT OPINION

In the absence of specific recommendations for pediatric CRC, the general therapeutic strategy should follow the same principles as for adults and should be the result of a multidisciplinary discussion. Patient access to optimal treatment is difficult due to the lack of new drugs approved for the pediatric age group and non-availability of clinical trials. Collaboration between pediatric and adult oncologists is considered crucial in order to overcome these issues and find solutions to increase knowledge and improve the outcome of such a rare disease in children.

Desmoplastic small round cell tumor: from state of the art to future clinical prospects

INTRODUCTION

Desmoplastic small round cell tumor (DSRCT) is an extremely rare and highly aggressive soft tissue sarcoma, presenting mainly in male adolescents and young adults with multiple nodules disseminated within the abdominopelvic cavity. Despite a multimodal approach including aggressive cytoreductive surgery, intensive multi-agent chemotherapy, and postoperative whole abdominopelvic radiotherapy, the prognosis for DSRCT remains dismal. Median progression-free survival ranges between 4 and 21 months, and overall survival between 17 and 60 months, with the 5-year overall survival rate in the range of 10-20%.

AREA COVERED

This review discusses the treatment strategies used for DSRCT over the years, the state of the art of current treatments, and future clinical prospects.

EXPERT OPINION

The unsatisfactory outcomes for patients with DSRCT warrant investigations into innovative treatment combinations. An international multidisciplinary and multi-stakeholder collaboration, involving both pediatric and adult sarcoma communities, is needed to propel preclinical model generation and drug development, and innovative clinical trial designs to enable the timely testing of treatments involving novel agents guided by biology to boost the chances of survival for patients with this devastating disease.

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.

Relapse after non-metastatic rhabdomyosarcoma: The impact of routine surveillance imaging on early detection and post-relapse survival

BACKGROUND

Patients with rhabdomyosarcoma (RMS) whose disease relapses have little chance of being cured, so front-line treatments are usually followed up with surveillance imaging in an effort to detect any recurrences as early as possible, and thereby improve post-relapse outcomes. The real benefit of such routine surveillance imaging in RMS remains to be demonstrated, however. This retrospective, single-center study examines how well surveillance imaging identifies recurrent tumors and its impact on post-relapse survival.

METHODS

The analysis concerned 79 patients <21 years old treated between 1985 and 2020 whose initially localized RMS relapsed. Clinical findings, treatment modalities, and survival were analyzed, comparing patients whose relapse was first suspected from symptoms they developed (clinical symptoms group) with those whose relapse was identified by radiological surveillance (routine imaging group).

RESULTS

Tumor relapses came to light because of clinical symptoms in 42 cases, and on routine imaging in 37. The time to relapse was much the same in the two groups. The median overall survival (OS) and 5-year OS rate were, respectively, 10 months and 12.6% in the clinical symptoms group, and 11 months and 27.5% in the routine imaging group (p-value .327). Among patients with favorable prognostic scores, survival was better for those in the routine imaging group (5-year OS 75.0% vs. 33.0%, p-value .047).

CONCLUSION

It remains doubtful whether surveillance imaging has any real impact on RMS relapse detection and patients' post-relapse survival. Further studies are needed to establish the most appropriate follow-up recommendations, taking the potentially negative effects of regular radiological exams into account.

Relapse after nonmetastatic rhabdomyosarcoma: Salvage rates and prognostic variables

BACKGROUND

Patients with relapsing rhabdomyosarcoma (RMS) pose a therapeutic challenge, and the survival rate is reportedly poor. We describe a retrospective series of relapsing RMS patients treated at a referral center for pediatric sarcoma, investigating the pattern of relapse, salvage rates, and factors correlating with final outcomes.

METHODS

The analysis concerned 105 patients <21 years old treated from 1985 to 2020 with initially localized RMS at first relapse. For risk-adapted stratification purposes, patient outcomes were examined using univariable and multivariable analyses based on patients' clinical features at first diagnosis, first-line treatments, clinical findings at first relapse, and second-line treatments.

RESULTS

First relapses occurred 0.08-4.8 years (median 1 year) following initial diagnosis and were local/locoregional in 59% of cases. Treatment at first relapse included chemotherapy in all but two cases, radiotherapy in 38, and surgery in 21. Median event-free survival (EFS) after first relapse was 4 months, while 5-year EFS was 16.3%; median overall survival (OS) was 9 months, while 5-year OS was 16.7%. Several variables influenced survival rates. Considering only clinical findings and treatment at relapse, Cox's multivariable analysis showed that OS correlated significantly with time to relapse, radiotherapy administered at relapse, response to chemotherapy, and whether a second remission was achieved.

CONCLUSION

Survival following first relapse of patients with localized RMS at initial diagnosis is poor. The variables found to influence survival can be utilized in a risk-adapted model to estimate the chances of salvage to guide decisions for second-line treatments.

MiR-223 Exclusively Impairs In Vitro Tumor Growth through IGF1R Modulation in Rhabdomyosarcoma of Adolescents and Young Adults

Adolescents and young adults (AYA) with rhabdomyosarcoma (RMS) form a subgroup of patients whose optimal clinical management and best possible access to care remain a challenge and whose survival rates lag behind that of children diagnosed with histologically similar tumors. A better understanding of tumor biology that differentiates children (PEDS-) from AYA-RMS could provide critical information and drive new initiatives to improve their final outcome. We investigated the functional role of miRNAs implicated in AYA-RMS development, as they have the potential to lead to discovery of new targets pathways for a more tailored treatment in these age groups of young RMS patients. MiR-223 and miR-486 were observed de-regulated in nine RMS tissues compared to their normal counterparts, yet only miR-223 replacement impaired proliferation and aggressiveness of AYA-RMS cell lines, while inducing apoptosis and determining cell cycle arrest. Interestingly, IGF1R resulted in the direct target of miR-223 in AYA-RMS cells, as demonstrated by IGF1R silencing. Our results highlight an exclusive functional role of miR-223 in AYA-RMS development and aggressiveness.

Metastatic rhabdomyosarcoma: Evidence of the impact of radiotherapy on survival. A retrospective single-center experience

BACKGROUND

The prognosis for patients with metastatic rhabdomyosarcoma (RMS) remains largely unsatisfactory despite the adoption of intensive multimodal therapy. To assess the role of different treatments adopted over the years, we retrospectively analyzed a cohort of patients &lt;21 years old with metastatic RMS, treated from 1990 to 2020 at a referral center for pediatric sarcomas.

METHODS

Patients were treated using a multimodal approach that included surgery, radiotherapy, and chemotherapy (both high-dose chemotherapy and maintenance therapy in some cases). The type of radiotherapy administered was categorized as radical (to all sites of disease); partial (to at least one, but not all sites of disease); or none. A landmark analysis was used to examine the impact of radiotherapy on survival, that is, patients who had an event before day 221 were excluded from the analysis.

RESULTS

The series included 80 patients. Event-free survival (EFS) and overall survival (OS) rates at 5 years were 17.3% and 21.3%, respectively. Survival was significantly associated with radiotherapy to metastatic sites, and with the radiotherapy category. In particular, 5-year EFS and OS rates were 70.6% and 76.0% for patients given radical radiotherapy, and 4.8% and 10.7%, respectively, for those given partial radiotherapy or none. Using the Cox multivariable analysis, OS correlated significantly with radiotherapy category.

CONCLUSIONS

While confirming the poor overall outcome of patients with metastatic RMS, this study identified radiotherapy-when given to all sites of disease (including metastases)-as the main variable influencing survival.

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.

Primary lung carcinoma in children and adolescents: An analysis of the European Cooperative Study Group on Paediatric Rare Tumours (EXPeRT)

BACKGROUND

Primary lung carcinoma is an exceptionally rare childhood tumour, as per definition of the European Cooperative Study Group on Paediatric Rare Tumours (EXPeRT), with an incidence of 0.1-0.2/1,000,000 per year. Little is known about the clinical characteristics of children with primary lung carcinoma, a gap which this joint analysis of the EXPeRT group aimed to fill.

PATIENTS AND METHODS

We performed a retrospective case series of children (aged 0-18 years) with primary lung carcinoma, as collected through the EXPeRT databases between 2000 and 2021. We recorded relevant clinical characteristics including treatment and outcome.

RESULTS

Thirty-eight patients were identified with a median age of 12.8 years at diagnosis (range: 0-17). Mucoepidermoid carcinoma (MEC) was the most frequent entity (n = 20), followed by adenocarcinoma (n = 12), squamous cell carcinoma (n = 4), adenosquamous carcinoma (n = 1) and small-cell lung cancer (n = 1). Patients with MEC presented rarely with lymph node metastases (2/20 cases). Overall, 19/20 patients achieved long-lasting remission by surgical resection only. Patients with other histologies often presented in advanced stages (14/18 TNM stage IV). With multimodal treatment, 3-year overall survival was 52% ± 13%. While all patients with squamous cell carcinoma died, the 12 patients with adenocarcinoma had a 3-year overall survival of 64% ± 15%.

CONCLUSIONS

Primary lung carcinomas rarely occur in children. While the outcome of children with MEC is favourable with surgery alone, patients with other histotypes have a poor prognosis, despite aggressive treatment, highlighting the need to develop new strategies for these children, such as mutation-guided treatment.

How ten-years of reirradiation for paediatric high-grade glioma may shed light on first line treatment

PURPOSE

Recurrence incidence for paediatric/adolescent high-grade glioma (HGG) exceeds 80%. Reirradiation (reRT) palliates symptoms and delays further progression. Strategies for reRT are scarce: we retrospectively analysed our series to develop rational future approaches.

METHODS

We re-evaluated MRI + RT plans of 21 relapsed HGG-patients, accrued 2010-2021, aged under 18 years. All underwent surgery and RT + chemotherapy at diagnosis. Pathologic/molecular re-evaluation allowed classification based on WHO 2021 criteria in 20/21 patients. Survival analyses and association with clinical parameters were performed.

RESULTS

Relapse after 1st RT was local in 12 (7 marginal), 4 disseminated, 5 local + disseminated. Re-RT obtained 8 SD, 1 PR, 1PsPD, 1 mixed response, 10 PD; neurological signs/symptoms improved in 8. Local reRT was given to 12, followed again by 6 local (2 marginal) and 4 local + disseminated second relapses in 10/12 re-evaluated. The 4 with dissemination had 1 whole brain, 2 craniospinal irradiation (CSI), 1 spine reRT and further relapsed with dissemination and local + dissemination in 3/four assessed. Five local + disseminated tumours had 3 CSI, 1 spine reRT, further progressing locally (2), disseminated (1), n.a. (1). Three had a third RT; three were alive at 19.4, 29, 50.3 months after diagnosis. Median times to progression/survival after re-RT were 3.7 months (0.6-16.2 months)/6.9 months (0.6-17.9 months), improved for longer interval between 1st RT and re-RT (P = 0.017) and for non-PD after reRT (P < 0.001). First marginal relapse showed potential association with dissemination after re-RT (P = 0.081).

CONCLUSIONS

This is the biggest series of re-RT in paediatric HGG. Considering the dissemination observed at relapse, our results could prompt the investigation of different first RT fields in a randomized trial.

A homogeneous treatment for non-DIPG diffuse midline glioma

INTRODUCTION

The H3K27M-mutant diffuse midline glioma (DMG) was first included in the World Health Organization (WHO) Classification of central nervous system (CNS) tumors in 2016, and confirmed in its fifth edition. The biological behavior and dismal prognosis of this tumor resemble diffuse intrinsic pontine gliomas (DIPG). Homogeneously-treated series are rarely reported.

METHODS

From 2016 onwards, we treated patients with DMG with radiotherapy and concomitant/adjuvant nimotuzumab/vinorelbine, plus re-irradiation at relapse, as already done for DIPG.

RESULTS

We treated nine patients, seven females, with a median age at diagnosis of 13 years. Tumor sites were: thalamic in five cases, pontocerebellar in two, pineal in one, and paratrigonal with nodular/leptomeningeal dissemination in one. Three patients were biopsied, and six had partial tumor resections. Central pathological review was always performed. The median time to local progression was 12.7 months, and the median overall survival was 17.8 months. Six patients died of tumor progression, one of cerebral bleeding at progression. Two were alive, one in continuous remission, the other after relapsing, at 38.6 and 46.3 months after diagnosis. Progression-free survival was 33.3% at one year. Overall survival was 88.9%, 33.3% and 22.2% at 1, 2 and 3 years, respectively.

CONCLUSIONS

This is a small series of homogeneously-treated DMG patients. The results obtained are comparable with those of DIPG patients. Given the phenotypically- and molecularly-defined setting of DMG and severe outcome in this orphan population, they should be treated and included in registries and protocols of DIPG.

Extraosseous Ewing sarcoma in children and adolescents: A retrospective series from a referral pediatric oncology center

BACKGROUND

Extraosseous Ewing sarcoma is a rare entity and less is known about its clinical behavior and optimal treatment than for its counterpart in bone. This study is a retrospective analysis on a cohort of patients <21 years treated according to a "soft tissue sarcoma approach."

METHODS

The "extraosseous" origin of the tumor was established on radiological findings, based on the lack of any bone involvement. Patients were treated using a multimodality approach including surgery, radiotherapy, and chemotherapy. All patients received chemotherapy with alkylating agents and anthracyclines for 25 weeks (nine courses). Radiotherapy (45-54.8 Gy) was required for all cases except those who had an initial R0 resection of tumors smaller than 5 cm.

RESULTS

Fifty-seven patients (age 2-20 years, median 14) were treated from 1990 to 2020. Ten-year event-free survival (EFS) and overall survival (OS) were 77.5% and 85.5% in patients with localized disease, and 11.1% and 29.6% in those with metastatic disease (p < .001) (follow-up 5-349 months, median 107 months). In patients with localized disease, the most recent IVADo-IVE regimen achieved excellent survivals, that is, 10-year EFS 95.5%.

CONCLUSIONS

Our study showed that satisfactory results were achieved in patients with localized extraosseous Ewing sarcoma treated with a tailored approach derived from soft tissue sarcoma protocols, which was less intensive and shorter as compared to the standards utilized for the management of bone Ewing sarcoma. Our study suggests that the extraskeletal site might be considered as a variable to stratify patients and modulate treatment intensity accordingly in Ewing sarcoma protocol.

Trabectedin-irinotecan, a potentially promising combination in relapsed desmoplastic small round cell tumor: report of two cases

Effective new drugs are urgently needed for desmoplastic small round cell tumor (DSRCT), an extremely rare and aggressive disease with a generally poor prognosis. We describe two heavily-pretreated young patients with advanced-stage DSRCT given third-line treatment with a combination of trabectedin and irinotecan, based on our preclinical data demonstrating its effect on patient-derived xenografts. This trabectedin-irinotecan treatment showed a limited toxicity. One patient had a mixed response (overall stable disease), the other a complete tumor remission. This is the first report of preliminary findings to suggest that combining trabectedin and irinotecan is worth further investigating as a potentially valuable chemotherapy for DSRCT.

Managing Care during the COVID-19 Pandemic: The Point of View and Fears of Pediatric Cancer Patients’ Families

(1) Background: When the COVID-19 pandemic arrived, changes had to be made to several management aspects at our Pediatric Oncology Unit. We investigated how the families perceived these changes. (2) Methods: Two questionnaires were developed at the Pediatric Oncology Unit of the Istituto Nazionale dei Tumori in Milan in order to explore how the pandemic had affected the experience of patients who had been or were being treated at our hospital, as well as their families. These questionnaires were administered to three groups of individuals. (3) Results: Between July and October 2020, 120 questionnaires were administered to parents of patients. The impact of school closures and the impossibility of attending sports and social activities outside the hospital were regarded as important, and it was reported that 77.5% of parents judged social distancing to have affected their children. Regarding the changes introduced in the management of the ward and outpatient clinic, most parents’ opinions were positive. Differences in the opinions expressed by Groups 2 and 3 were statistically significant on the topics of relationships in the ward and staff workload. The aspect most negatively affected by the pandemic was the support that patients’ parents were able to give each other. Regardless of whether patients were treated before the pandemic or after the first lockdown, all parents indicated strong degrees of satisfaction with the care received and the organizational arrangements. (4) Conclusions: The results of our study point us in the right direction to further improve our daily work and better respond to the needs of our patients and their families.

Genomic predictors of response to PD-1 inhibition in children with germline DNA replication repair deficiency

Cancers arising from germline DNA mismatch repair deficiency or polymerase proofreading deficiency (MMRD and PPD) in children harbour the highest mutational and microsatellite insertion–deletion (MS-indel) burden in humans. MMRD and PPD cancers are commonly lethal due to the inherent resistance to chemo-irradiation. Although immune checkpoint inhibitors (ICIs) have failed to benefit children in previous studies, we hypothesized that hypermutation caused by MMRD and PPD will improve outcomes following ICI treatment in these patients. Using an international consortium registry study, we report on the ICI treatment of 45 progressive or recurrent tumors from 38 patients. Durable objective responses were observed in most patients, culminating in a 3 year survival of 41.4%. High mutation burden predicted response for ultra-hypermutant cancers (>100 mutations per Mb) enriched for combined MMRD + PPD, while MS-indels predicted response in MMRD tumors with lower mutation burden (10–100 mutations per Mb). Furthermore, both mechanisms were associated with increased immune infiltration even in ‘immunologically cold’ tumors such as gliomas, contributing to the favorable response. Pseudo-progression (flare) was common and was associated with immune activation in the tumor microenvironment and systemically. Furthermore, patients with flare who continued ICI treatment achieved durable responses. This study demonstrates improved survival for patients with tumors not previously known to respond to ICI treatment, including central nervous system and synchronous cancers, and identifies the dual roles of mutation burden and MS-indels in predicting sustained response to immunotherapy.

Hypermutation and microsatellite burden determine responses and long-term survival following PD-1 blockade in children and young adults with refractory cancers resulting from germline DNA replication repair deficiency.

Prolonged COVID-19 infection in a child with lymphoblastic non-Hodgkin lymphoma: which is the best management?

During the coronavirus disease 2019 (COVID-19) pandemic, oncologists have managed patients at higher risk of having a severe course of this infection. This raises new questions about their correct management, as well as the difficulty of distinguishing tumor/treatments complications from those related to COVID-19. We report a case of an 11-year-old boy undergoing treatment for T-cell lymphoblastic lymphoma who experienced a prolonged COVID-19 course. Oncologic therapy was continued without significant changes compared to the initially planned treatment. No relevant complications occurred. COVID-19 convalescent plasma was administered, resulting in a positive antibody titer after 24 days.

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.

Langerhans cell histiocytosis in adults: a retrospective, single-center case series

Langerhans cell histiocytosis is rare in adults, and most of what we know about its diagnosis and treatment comes from pediatric studies. We report clinical findings and results of treatment in a retrospective series of 63 consecutive adult patients (18-76 years old), treated at our pediatric unit from 1990 to 2020 using the same approach as for children. Patients were classified as having single-system disease (SS-LCH) in 41 cases, which was unifocal in 34 of them and multifocal in 7, or multisystem disease (MS-LCH) in 17 and primary pulmonary (pLCH) in 5. Twenty patients also had diabetes insipidus. A "wait and see" strategy was recommended after biopsy/surgery for patients with unifocal SS-LCH. Systemic treatment was proposed for cases of SS-LCH involving "special sites" or with multifocal disease, and in cases of MS-LCH. EFS and OS for the cohort as a whole were 62.2% and 100%, respectively, at 5 years and 52.5% and 97.6% at 10 years. Three patients died due to the damage caused by the multiple therapies administered. The rate of disease reactivation was high (affecting 40% of cases), with several reactivations over the years despite multiple lines of treatment. Though clinical history of LCH may differ between adults and children, in the absence of specific, tailored protocols, clinical approach to adult cases may draw on pediatric experience. Patients with limited disease have a good prognosis without any need for systemic therapy. Potentially greater toxicity in adults of systemic treatments generally used in pediatric setting should be borne in mind.

SARS-CoV-2 vaccination for adolescents and young adult patients treated at a specialist pediatric oncology unit

This brief report describes the SARS-CoV-2 vaccination program at our pediatric oncology unit. Adopting Italian regulations, patients treated for cancer within the previous 6 months were offered vaccination with the Pfizer-BioNtech vaccine if aged ≥16 years, and with the Pfizer-BioNtech or Moderna vaccine if aged ≥18 years. From March 24 to April 28, 2021, 80/89 adolescent and young adult patients enrolled were vaccinated, while nine refused the vaccine due to fear of side effects, disbelief regarding the pandemic, or lack of trust in the scientific community. The refusal rate in our cohort was lower than in the Italian general population.

Children and adolescent solid tumours and high-intensity end-of-life care: what can be done to reduce acute care admissions?

Despite improvements in survival, cancer remains the leading cause of non-accidental death in children and adolescents, who risk receiving high-intensity end-of-life (HI-EOL) care.

OBJECTIVE

To analyse treatments for relapses (particularly in the last weeks of life), assess their impact on the EOL, identify patients most likely to receive HI-EOL care and examine whether palliative care services can contain the intensity of EOL care.

METHODS

This retrospective study involved patients treated at the paediatric oncology unit of the Istituto Nazionale Tumori in Milan who died between 2018 and 2020. The primary outcome was HI-EOL care, defined as: ≥1 session of intravenous chemotherapy <14 days before death; ≥1 hospitalisation in intensive care in the last 30 days of life and ≥1 emergency room admission in the last 30 days of life.

RESULTS

The study concerned 68 patients, and 17 had HI-EOL care. Patients given specific in-hospital treatments in the last 14 days of their life more frequently died in hospital. Those given aggressive EOL care were less likely to die at home or in the hospice. Patients with central nervous system (CNS) tumours were more likely to have treatments requiring hospitalisation, and to receive HI-EOL care.

CONCLUSION

These results underscore the importance of considering specific treatments at the EOL with caution. Treatments should be administered at home whenever possible.The early activation of palliative care, especially for fragile and complicated patients like those with CNS cancers, could help families cope with the many problems they face.

DICER1-associated malignancies mimicking germ cell neoplasms: Report of two cases and review of the literature

DICER1 syndrome is characterized by a unique combination of features and a growing list of associated rare tumors. Traditionally, gonadal or extra-gonadal teratomas have not been considered part of this spectrum, with only rare DICER1-related teratoid neoplasms recently reported. Besides, their methylation profiles remain elusive. We report two DICER1-associated malignancies involving the lumbar spine of a 22-year-old man (case 1) and the pelvic cavity of a 14-year-old girl (case 2). Both tumors exhibited teratoma-like features with a high-grade malignant somatic component, including rhabdomyosarcomatous elements for case 1 and a malignant neuroectodermal neoplasm with features of an embryonal tumor with multilayered rosettes (ETMR) for case 2. Both tumors showed strong SALL4 expression and H3K27me3 loss by immunohistochemistry. Next-generation sequencing studies confirmed biallelic DICER1 mutations with additional pathogenic missense mutations in KRAS (case 1) and CTNNB1 (case 2). The methylation profile of case 1 clustered with DICER1-associated sarcomas, whereas case 2 classified as an ETMR (albeit low raw and calibrated score). In conclusion, we report two DICER1-related malignancies with teratoma-like features, further expanding their morphologic spectrum and highlighting the multipotentiality of their presumed cell of origin. Notably, we describe the first ETMR identified outside the CNS with a documented DICER1 biallelic inactivation. Our findings also highlight the potential role of other molecular alterations such as KRAS and CTNNB1 mutations in defining the phenotype of embryonal and primitive DICER1-associated neoplasms, a notion that deserves further studies.

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.

Integrating irinotecan in standard chemotherapy: A novel dose-density combination for high-risk pediatric sarcomas

BACKGROUND

Irinotecan is a drug active against pediatric sarcomas with a toxicity profile that theoretically allows for its association with more myelotoxic drugs. We examined the feasibility of a dose-density strategy integrating irinotecan in standard chemotherapy regimens for patients with high-risk sarcomas.

METHODS

Between November 2013 and January 2020, 23 patients ≤25 years old were included in the study. Eleven patients newly diagnosed with metastatic disease received nine cycles of IrIVA (irinotecan-ifosfamide-vincristine-actinomycin D; ifosfamide 3 g/m² on days 1 and 2, vincristine 1.5 mg/m² on day 1, actinomycin D 1.5 mg/m² on day 1, irinotecan 20 mg/m² for 5 consecutive days starting on day 8) as first-line therapy. Two relapsed patients received IrIVA and 10 IrVAC (irinotecan-vincristine-actinomycin D-cyclophosphamide; cyclophosphamide 1.5 g/m² on day 1 instead of ifosfamide). Feasibility was assessed in terms of toxicity and time to complete the treatment.

RESULTS

Seventeen rhabdomyosarcomas, four Ewing sarcomas, two desmoplastic small round cell tumors received a total of 181 cycles (range 2-10). Grade 4 neutropenia occurred in 62.4% of the cycles. Thirteen patients had febrile neutropenia. Diarrhea occurred in 14 cycles. The median time to complete the treatment was 195 days (range 170-231), 83.4% of cycles were administered on time or with a delay <1 week. With a median follow-up of 2.6 years (range 0.2-5.0), 12 patients are alive, nine complete remissions, three with the disease.

CONCLUSIONS

A dose-density strategy combining irinotecan with standard chemotherapy is feasible. This approach will be investigated in the next trial coordinated by the European pediatric Soft tissue sarcoma Study Group.

Correlation between oncological family history and clinical outcome in a large monocentric cohort of pediatric patients with rhabdomyosarcoma

BACKGROUND

Rhabdomyosarcoma (RMS), an aggressive soft tissue sarcoma of the skeletal muscle generally affecting children and adolescents, shows extensive heterogeneity in histology, site and age of onset, clinical course, and prognosis. Tumorigenesis of RMS is multifactorial and genetic predisposition together with the family history of cancer may provide critical information to enhance the current knowledge and foster genetic counseling and testing.

METHODS

In our study, we evaluated the possible correlation of oncological family history with clinical outcomes in a cohort of RMS 512 patients and treated at the Pediatric Oncology Unit of our Institute. Family history was retrospectively collected from the specific ad hoc form available in medical records and filled in through an interview with the patients' parents at the time of RMS diagnosis.

RESULTS

While our series did not show a specific association between oncological family history and clinical variables, we observed an association with survival probabilities: among patients with a history of cancer-affected first-degree relatives at the time of the diagnosis, all children with alveolar RMS (ARMS) died of disease.

CONCLUSION

Our study not only reports an interesting and not previously described association between a poor clinical outcome and ARMS in patients with young cancer-affected relatives, but also stimulates the discussion on oncological family history in RMS, to improve the clinical management of these young patients and their families.

Cutaneous melanoma in children and adolescents: The EXPeRT/PARTNER diagnostic and therapeutic recommendations

Cutaneous melanoma is rare in children and, like other very rare pediatric tumors, it suffers from a shortage of knowledge and clinical expertise. The clinical management of pediatric melanoma is often challenging. Its clinical and pathological diagnosis may be difficult, and there is no standard treatment. In the absence of specific treatment guidelines, young patients are generally treated following the same principle as for adults, but concern remains about their access to clinical trials and new drugs, which have been shown to dramatically change the natural history of advanced melanoma. This paper presents the internationally recognized recommendations for the diagnosis and treatment of children and adolescents with cutaneous melanoma, established by the European Cooperative Study Group for Pediatric Rare Tumors (EXPeRT) within the EU-funded project called PARTNER (Paediatric Rare Tumours Network - European Registry). Main recommendations for melanoma are to discuss pediatric patients in multidisciplinary teams that include both pediatric oncologists and specialists in adult melanoma; to enroll patients in prospective trials, if available; to collect data in national-international databases; and to develop an effective international collaboration between pediatric and adult melanoma groups in order to facilitate the transfer of potentially effective new agents from the adult to the pediatric setting.

Survival Benefit for Individuals With Constitutional Mismatch Repair Deficiency Undergoing Surveillance

Constitutional mismatch repair deficiency syndrome (CMMRD) is a lethal cancer predisposition syndrome characterized by early-onset synchronous and metachronous multiorgan tumors. We designed a surveillance protocol for early tumor detection in these individuals.

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.

Medulloblastoma and familial adenomatous polyposis: Good prognosis and good quality of life in the long-term?

INTRODUCTION

Mutations of the APC (adenomatous polyposis coli) gene correlate mainly with familial adenomatous polyposis (FAP), but can occasionally be pathogenic for medulloblastoma (MBL) wingless-related integration site (WNT) subtype, the course of which has only recently been described.

METHODS

We retrieved all patients with documented germline APC mutations and a diagnosis of MBL to examine their outcome, late effects of treatment, and further oncological events.

RESULTS

Between 2007 and 2016, we treated six patients, all with a pathogenic APC variant mutation and all with MBL, classic histotype. None had metastatic disease. All patients were in complete remission a median 65 months after treatment with craniospinal irradiation at 23.4 Gy, plus a boost on the posterior fossa/tumor bed up to 54 Gy, followed by cisplatin/carboplatin, lomustine, and vincristine for a maximum of eight courses. Five of six diagnostic revised MRI were suggestive of the WNT molecular subgroup typical aspects. Methylation profile score (in two cases) and copy number variation analysis (chromosome 6 deletion in two cases) performed on four of six retrieved samples confirmed WNT molecular subgroup. Four out of six patients had a positive family history of FAP, while gastrointestinal symptoms prompted its identification in the other two cases. Four patients developed other tumors (desmoid, MELTUMP, melanoma, pancreatoblastoma, thyroid Tir3) from 5 to 7 years after MBL.

DISCUSSION

Our data confirm a good prognosis for patients with MBL associated with FAP. Patients' secondary tumors may or may not be related to their syndrome or treatment, but warrant adequate attention when planning shared guidelines for these patients.

Extra-appendicular neuroendocrine tumors: A report from the TREP project (2000-2020)

BACKGROUND

Extra-appendicular neuroendocrine tumors (NETs) are very rare tumors. While diagnostic and therapeutic guidelines are well established for adults, data on children and adolescents are lacking.

PATIENTS AND METHODS

Patients with a diagnosis of extra-appendicular NET registered on the Tumori Rari in Età Pediatrica - Rare Tumors in Pediatric Age (TREP) from 2000 to 2020 were analyzed. Clinical characteristics including patients' presentation, tumor features, treatment, and outcome were reviewed.

RESULTS

Twenty-seven patients with extra-appendicular NET registered on TREP with a median age of 173 months. The primary site was the pancreas (12) or bronchi (10) in the majority of cases. Other primary sites included the thymus, Meckel's diverticulum, and liver. Thirteen (48%) of tumors extended beyond the organ of origin: four invaded neighboring organs and/or regional nodes and nine involved distant metastases. The 3-year event-free survival (EFS) for those with localized disease was superior to those with metastatic disease (66.6% 95% CI 5-95% vs 33% 95% CI 5-68%, respectively; P = .005). A complete resection was feasible in 17 patients. The 3-year EFS in these patients was superior to those with no or incomplete resection (R0 vs R1/R2, respectively; P = .007). Overall, 16 children had no evidence of disease at follow-up, and one is alive with disease; five died, and five were lost to follow-up.

CONCLUSIONS

Data from our experience demonstrated a wide heterogeneity of presentation and outcome of these tumors. Localized disease and complete surgical resection were the main prognostic factors of good outcome. Other therapies may have a role in prolonging survival in metastatic disease.

Multiagent chemotherapy including IrIVA regimen and maintenance therapy in the treatment of desmoplastic small round cell tumor

This study reports the treatment feasibility and efficacy of a novel multiagent intensive treatment program for young patients with desmoplastic small round cell tumor. This small series includes three patients and should be seen as a first suggestion of integration of the dose density and the maintenance chemotherapy concept. The IrIVA regimen (irinotecan, ifosfamide, vincristine, and actinomycin-D) is added-used at a short interval between chemotherapy administrations-at more classic intensive ifosfamide-based regimens. The vinorelbine and low-dose oral cyclophosphamide maintenance therapy is added at the end of conventional chemotherapy to achieve an antiangiogenic effect.

Adolescents with cancer on privacy: Fact-finding survey on the need for confidentiality and space

BACKGROUND

Cancer diagnosis and related treatment can limit young patients' privacy. Their need for private physical and psychological spaces can be impeded by limited freedom, e.g., sharing hospital rooms with others and exposing their body to their parents and doctors.

METHODS

We conducted a survey among young patients of our center to investigate how their perception of privacy changed after being diagnosed with cancer and their need for hospital dedicated physical spaces and time for patients to enjoy their privacy. A questionnaire with 16 items was developed by the staff involving psychologists and physicians. The relevance of changes before and after the cancer diagnosis was assessed by calculating two scores indicating the situation before and after diagnosis for each answer, as well as a delta score.

RESULTS

Between May and June 2020, the questionnaire was completed by 60 patients aged 16-24 years. The median delta scores describing the changes before and after diagnosis were -8 points for perception of privacy, indicating a significant decrement of the level of privacy perceived. A major issue was the constant presence of parents being perceived as intrusive. Concerning hospital dedicated physical spaces and time for patients to enjoy their privacy, respondents requested dedicated spaces (50% of patients) and opportunities to have private interviews with medical personnel (88%).

CONCLUSIONS

Our study offers a snapshot of how young people with cancer perceive the impact of the disease and its treatment on their privacy with the restrictions imposed on their individual freedom. Patients' personal needs must be taken into consideration to adopt appropriate measures and better organize wards.

IMMU-18. FAVORABLE OUTCOME IN REPLICATION REPAIR DEFICIENT HYPERMUTANT BRAIN TUMORS TO IMMUNE CHECKPOINT INHIBITION: AN INTERNATIONAL RRD CONSORTIUM REGISTRY STUDY

Pediatric brain tumors with replication repair deficiency (RRD) are hypermutant and may respond to immune checkpoint inhibition (ICI). We performed a consortium registry study of ICI in recurrent RRD cancers. Clinical and companion biomarkers were collected longitudinally on all patients. Biomarkers included tumor mutational burden (TMB), neoantigens and genetic signatures obtained from whole genome and exome sequencing. Immune inference was obtained by RNAseq and T cell rearrangement was collected in the tumor and in blood throughout treatment. Of the 46 tumors on the study, 32 were brain tumors with glioblastoma in 96%. Rapid, objective responses (>50%) were observed in 50% of glioblastomas. Three year overall survival for the whole cohort was 48+/-8% which compares favorably with historical controls. Brain tumors fared worse with OS of 39+/-10% and late recurrences observed even after 2 years of therapy (p=0.02). Tumor size and acute “flare” constitute poor outcome throughout all cancers. While all tumors are hypermutant, TMB and predicted neoantigens correlated with response to ICI (p=0.02). Specific signatures extracted from SNVs and total mutations predicted response to ICI and favorable outcome (p=0.005). RNA inference and TCR reveal that the FLARE phenotype is mostly acute nonspecific immune response and not true progression. Finally, glioblastomas (n=8) which failed single agent ICI had favorable responses to combinational immunotherapies with prolonged survival of 65%+/-8% at one year after failure vs 0 for other patients (p=0.01). RRD glioblastomas exhibit favorable outcome and responses to ICI. Combinational therapies based on tumor and immune signatures of these cancers are necessary.

HGG-20. DIAGNOSTIC AND BIOLOGICAL ROLE OF METHYLATION PATTERNS IN REPLICATION REPAIR DEFICIENT HIGH GRADE GLIOMAS

Replication repair deficiency (RRD) is an important driving mechanism of pediatric high grade glioma (pHGG) occurring predominantly in the context of germline mutations in RRD-associated genes. Although pHGG present specific patterns of DNA methylation corresponding to driving oncogenic processes, methylation patterns have not been well studied in RRD tumors. We analyzed 52 RRD pHGG using either 450k or 850k methylation arrays. These arrays were compared with 234 PHGG driven by other genetic or epigenetic mechanisms and 10 additional pHGG samples known to be hypermutant. RRD pHGG displayed a methylation pattern corresponding to specific secondary mutations such as IDH1 and H3K27M. Strikingly, RRD pHGG lacking these known secondary mutations largely clustered together with a poorly described group previously labelled Wild type-C. Most of the hypermutant tumors clustered in a similar location suggesting undiagnosed RRD may be a driving force for tumors clustering in this location. Analysis of methylation patterns revealed that RRD pHGG displayed a unique CpG Island Demethylator Phenotype in contrast to the Methylator Phenotype described in other cancers. This effect was most concentrated at gene promotors. Prominent demethylation was observed in genes and pathways critical to cellular survival including cell cycle, gene expression, cellular metabolism and cellular organization. These data suggest that methylation profiles may provide diagnostic information for the detection of RRD pHGG. Furthermore, our findings highlight the unique natural selection pressures in these highly dysregulated, hypermutant cancers and provide novel impact of hypermutation and RRD on the cancer epigenome.

Defining the impact of prognostic factors at the time of relapse for nonmetastatic rhabdomyosarcoma

BACKGROUND

The prognosis for patients with relapsed rhabdomyosarcoma (RMS) depends on a number of variables, including tumor characteristics, type of relapse, and treatment received. All published studies have considered tumor characteristics at initial diagnosis, but not at the time of recurrence. In this study, we compared tumor characteristics at diagnosis and at the moment of local relapse to better define the chance of cure in this group of patients.

METHODS

We first analyzed 92 children with localized RMS treated according to the RMS96 and RMS2005 protocols who developed relapse after achieving complete remission at the end of treatment. Then we restricted our analysis to 51 patients with local recurrence to compare their initial tumor characteristics with those at relapse. All characteristics were studied using univariate and multivariate analyses.

RESULTS

The 10-year progression-free survival (PFS) and overall survival (OS) rates for the whole group were 23.5% (15.4-32.6) and 34.4% (24.8-44.1), respectively. On multivariate analysis, only primary tumor site appeared to have a strong impact on prognosis (P = .0010). The 10-year PFS and OS rates of patients with locoregional recurrences were 22.7% (12.3-35.0) and 34.9% (22.1-47.9), respectively. Multivariate analysis showed that tumors at unfavorable sites (P = .0044), and tumor size > 5 cm at recurrence (P = .0088) were associated with the poorest prognosis.

CONCLUSION

Our study demonstrates that to estimate the chance of cure in patients with relapsed RMS, we should also consider tumor characteristics at the time of relapse, and tumor size in particular.

Germline-driven replication repair-deficient high-grade gliomas exhibit unique hypomethylation patterns

Replication repair deficiency (RRD) leading to hypermutation is an important driving mechanism of high-grade glioma (HGG) occurring predominantly in the context of germline mutations in RRD-associated genes. Although HGG presents specific patterns of DNA methylation corresponding to oncogenic mutations, this has not been well studied in replication repair-deficient tumors. We analyzed 51 HGG arising in the background of gene mutations in RRD utilizing either 450 k or 850 k methylation arrays. These were compared with HGG not known to be from patients with RRD. RRD HGG harboring secondary mutations in glioma genes such as IDH1 and H3F3A displayed a methylation pattern corresponding to these methylation subgroups. Strikingly, RRD HGG lacking these known secondary mutations clustered together with an incompletely described group of HGG previously labeled "Wild type-C" or "Paediatric RTK 1". Independent analysis of two comparator HGG cohorts showed that other RRD/hypermutant tumors clustered within these subgroups, suggesting that undiagnosed RRD may be driving some HGG clustering in this location. RRD HGG displayed a unique CpG Island Demethylator Phenotype in contrast to the CpG Island Methylator Phenotype described in other cancers. Hypomethylation was enriched at gene promoters with prominent demethylation in genes and pathways critical to cellular survival including cell cycle, gene expression, cellular metabolism, and organization. These data suggest that methylation arrays may provide diagnostic information for the detection of RRD HGG. Furthermore, our findings highlight the unique natural selection pressures in these highly dysregulated, hypermutant cancers and provide the novel impact of hypermutation and RRD on the cancer epigenome.

VIVA (vinorelbine, ifosfamide, vincristine, actinomycin-D): A new regimen in the armamentarium of systemic therapy for high-risk rhabdomyosarcoma

The study reports the treatment feasibility, and secondly efficacy, of a novel chemotherapy regimen, which adds vinorelbine to the ifosfamide-vincristine-actinomycin-D combination (VIVA regimen), used in four patients with high-risk rhabdomyosarcoma. All patients received nine cycles of the VIVA regimen followed by maintenance chemotherapy with vinorelbine and cyclophosphamide. All patients experienced significant hematological toxicity, but no other major complications (in particular neurotoxicity) or required treatment dose modifications. We observed a major response after three cycles in all patients, and they remained alive after a median follow up of 11 months from diagnosis.

Secreting Germ Cell Tumors of the Central Nervous System: A Long-Term Follow-up Experience

INTRODUCTION

Due to the rarity of nongerminomatous germ cell tumors (NGGCT) with non-standard treatment as yet, we report retrospectively our 30 year experience with chemotherapy followed by craniospinal irradiation (CSI), plus a boost of whole ventricular irradiation (WVI)/tumor bed (TB), tailored to pre-radiation chemotherapy response.

METHODS

Between 1988 and 2016, 28 patients received four cycles of PEB (cisplatin/etoposide/bleomycin), then CSI, and two further PEB cycles. Between 1988 and1994, CSI was 25.5 Gy for patients in complete remission (CR), 30 Gy if in partial remission (PR) or metastatic, with a boost to TB up to 45-54 Gy. In the period of 1995-2010, the boost included WVI and any extra-ventricular tumor sites up to 45 Gy. After 2010, CSI was reduced to 25.5 Gy for all non-metastatic patients, and a boost was given only to TB up to 40.5/45.5 Gy, depending on patients' CR/PR status. After 2003, patients with alfafetoprotein (αFP) > 1000 ng/mL received intensified treatment, also including autologous stem cell transplantation.

RESULTS

Among 28 patients (23 males; median age 12 years, 6 metastatic), 25 responded to PEB, and three progressed (PD) after one to four cycles; 26 received radiotherapy obtaining 13 CR, 7 PR and 5 stable disease (SD), 1 PD; 6 (21%) died (5 for disease, 1 for pneumonia while in CR). Five-year overall survival (OS) and progression-free survival (PFS) were both 81%; 10 year OS and PFS 81% and 76%, respectively (median follow-up 11 years).

CONCLUSIONS

Survival for children with NGGCT, independently from disease extent, was encouraging. Further studies should elucidate which patients could benefit from reduced volume and dose irradiation.

Cancer treatment in disabled children

The incidence of cancer in children with intellectual disability has been poorly documented. We report our experience of treating children and adolescents with cancer and intellectual disability (40 patients), from 2004 to 2018. A treatment-sparing approach was adopted for 6 patients with severe intellectual impairment to minimize toxicity: a child with postpartum asphyxia and medulloblastoma did not receive radiotherapy; 1 patient with mitochondrial encephalopathy and a testicular germ cell tumor did not receive bleomycin and lung metastasectomy; 2 patients (1 with Down + West syndrome + Wilms tumor (WT) and 1 with Denys-Drash syndrome + WT) did not receive vincristine; 1 child with corpus callosum agenesis and anaplastic ependymoma did not receive chemotherapy; 1 child with structural chromosomal aberrations and a primitive neuro-ectodermal tumor received personalized chemotherapy. Heminephrectomy was performed in 4 patients with WT to preserve their kidney function. We found no statistically significant correlation between relapse or mortality rates and the use of a treatment-sparing approach. The 5-year overall survival (OS) and event-free survival (EFS) rates were 84.5% and 66.1% as opposed to 82.5% and 46.9%, respectively, for patients in our usual-treatment and treatment-sparing groups.Conclusion: We only opted for a treatment-sparing approach for patients with severe disabilities, and their OS was in line with that of children without intellectual disability. What is Known: • There are few reports on children/adolescents with cancer and intellectual disability (ID). • It is not clear how to manage them and whether a treatment sparing should be considered, especially in the case of severe disability. What is New: • Most patients received the standard cancer treatment and only in the case of severe disability, a therapeutic saving approach was applied. • No statistically significant correlations between relapse/mortality rates and the use of a treatment-sparing approach were found.

Experiencing Social Isolation (Even in the Era of COVID-19 Pandemic Lockdown): Teachings Through Arts from Adolescents with Cancer

The article describes how adolescents with cancer utilized an artistic approach to discuss about their social isolation caused by disease and treatment. With the help of professionals, 17 young patients closed in their isolation room described their ideal room (a bit real, a bit of a fantasy place) producing texts and images, subsequently put together into a book. In these days when people are forced to social isolation by the lockdown related to corovavirus disease 2019 pandemic, young patients teach us meaningful life lessons: how social confinement can become an opportunity to focus on yourself, and what is really important in life.