Age-related biological differences in children's and adolescents' very rare tumors

Very rare tumors (VRTs) in pediatric age represent many different diseases. They present an annual incidence < 2/1000,000 and correspond to about 11% of all cancers in patients aged 0–14 years. They can be roughly divided into two groups: one including tumors that are also rare in adults, and the other group includes adult-type tumors rarely encountered in children and adolescents. Although there is an obvious gap in knowledge regarding oncogenesis in pediatric cancers, there is some evidence of the involvement of various signalling pathways in the development of tumors in children and adolescents and sometimes in young adults. In addition, despite the rarity of these neoplasms, several attempts have been made to disclose the underlying mechanisms. More effort and resources have urgently to be devoted to deepening current knowledge and integrating new findings into the therapeutic approach, which nowadays relies on the treatment modalities used in adult oncology. The aim of this paper is to provide a review of the main solid VRTs occurring in both the pediatric and the adult age groups, highlighting the variability between groups in their biological and clinical course

Adrenocortical tumours in children and adolescents: The EXPeRT/PARTNER diagnostic and therapeutic recommendations

Adrenocortical tumours (ACTs) are rare during childhood. A complete surgical resection provides the best chance of cure, but the role and efficacy of the adjuvant therapy are still controversial. Various histologic criteria of malignancy for ACTs adopted in children do not facilitate comparative studies and are not completely shared. Therefore, a sharp demarcation between benign and malignant lesions has not been recognised, making it difficult to identify who potentially needs perioperative therapy. This manuscript presents the internationally harmonised recommendations for the diagnosis and treatment of ACTs in children and adolescents, established by the European Cooperative Study Group for Paediatric Rare Tumours (EXPeRT) group within the EU-funded project PARTNER (Paediatric Rare Tumours Network - European Registry)

The role of cancer predisposition syndrome in children and adolescents with very rare tumours

Germline predisposing pathogenic variants (GPVs) are present in approximately 8 to 10% of children with all cancer types. Very rare tumours (VRTs) represent many different diseases, defined with an annual incidence < 2 / 1,000,000, and correspond to 11% of all cancers in patients aged 0-14 years. Some of these VRTs, including cancer typical for adults, develop in children with a cancer predisposition syndrome (CPS). Classically, three situations lead to consider this association: Some patients develop a VRT for which histology itself strongly suggests a GPV related to a CPS; others are referred for germline genetic testing because of a family or personal history and finally, a systematic molecular genomic tumour analysis, reveals a PV typical to a CPS. Depending on the samples tested and type of analysis performed, information can be directly available about the germline status of such a PV. Depicting the association between CPS and VRT is clinically important as some of these tumour types require adapted therapy, sometimes in the frontline setting, and the proposal of a specific surveillance programme to detect other malignancies. The diagnosis of CPS necessitates a careful familial evaluation and genetic counselling regarding the risks faced by the child or other family members. The aim of this paper is to propose a literature review of solid VRTs occurring in paediatric and young adult patients associated with CPSs

Value of the Sentinel Node Procedure in Pediatric Extremity Rhabdomyosarcoma: A Systematic Review and Retrospective Cohort Study

Background: Our aim is to show whether the sentinel node procedure (SNP) is recommendable for pediatric patients with extremity rhabdomyosarcoma (RMS). Lymph node metastases are an important prognostic factor in pediatric patients with extremity RMS. Accurate nodal staging is necessary to treat the patient accordingly. An alternative to the current recommended lymph node sampling is the sentinel node procedure (SNP). Methods: A systematic review was performed summarizing all published cases of SNP in addition to 13 cases from our hospital and 8 cases from two other hospitals that have not been published before. Results: For all patients (n = 55), at least one SLN was identified, but the SNP technique used was not uniform. The SNP changed the nodal classification of eight patients (17.0%) and had a false-negative rate of 10.5%. Conclusions: The SNP is recommendable for pediatric patients with extremity RMS. It can change lymph node status and can be used to sample patients in a more targeted way than nodal sampling alone. Therefore, we recommend use of the SNP in addition to clinical and radiological nodal assessment for pediatric patients with extremity RMS

The role of cancer predisposition syndrome in children and adolescents with very rare tumours

Germline predisposing pathogenic variants (GPVs) are present in approximately 8–10 % of children with all cancer types. Very rare tumours (VRTs) represent many different diseases, defined with an annual incidence < 2 / 1,000,000, and correspond to 11 % of all cancers in patients aged 0–14 years. Some of these VRTs, including cancer typical for adults, develop in children with a cancer predisposition syndrome (CPS). Classically, three situations lead to consider this association: Some patients develop a VRT for which histology itself strongly suggests a GPV related to a CPS; others are referred for germline genetic testing because of a family or personal history and finally, a systematic molecular genomic tumour analysis, reveals a PV typical to a CPS. Depending on the samples tested and type of analysis performed, information can be directly available about the germline status of such a PV. Depicting the association between CPS and VRT is clinically important as some of these tumour types require adapted therapy, sometimes in the frontline setting, and the proposal of a specific surveillance programme to detect other malignancies. The diagnosis of CPS necessitates a careful familial evaluation and genetic counselling regarding the risks faced by the child or other family members. The aim of this paper is to propose a literature review of solid VRTs occurring in paediatric and young adult patients associated with CPSs

Rationale for the treatment of children with CCSK in the UMBRELLA SIOP-RTSG 2016 protocol

The International Society of Paediatric Oncology-Renal Tumour Study Group (SIOP-RTSG) has developed a new protocol for the diagnosis, treatment, and follow-up monitoring of childhood renal tumours-the UMBRELLA SIOP-RTSG 2016 protocol (the UMBRELLA protocol). This protocol has been designed to continue international collaboration in the treatment of childhood renal tumours and will be implemented in over 50 different countries. Clear cell sarcoma of the kidney, which is a rare paediatric renal tumour that most commonly occurs in childre

The current status of treatment of Wilms′ tumor as per the SIOP trials

This paper attempts to briefly describe the International Society of Paediatric Oncology (SIOP) policy of treatment of nephroblastoma since first study (SIOP 1) launched in 1971 until today. It focuses on the advantages of the preoperative chemotherapy and the stratification of patients induced this way. Marked efficacy of the pretreatment opened the way for less aggressive surgical management also in case of the "so-called" regular unilateral cases: Nephron-sparing surgery and minimal invasive techniques will probably find its place in this field of pediatric surgical oncology; however, very careful selection of cases must be the priority