Value of Right-sided Hemicolectomy for Chldren With High-risk Neuroendocrine Tumors of the Appendix

Study Overview
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Brief Summary
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The goal of this observational study is to investigate the beneficial value of complementary surgery for appendiceal neuro-endocrine tumours in children. .

Detailed Description
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Aim Current guidelines recommend complementary right-sided hemicolectomy for high-risk (pT2(with risk factors)/pT3) neuro-endocrine tumors (NET) of the appendix (based on adult studies). In contrast to adults, high-risk NET of the appendix in children seems to be a relatively benign disease with high disease-free survival (100% versus 70-80% in adults), but high quality data are lacking. Therefore these recommendations are now being questioned. We aim to investigate the value of complementary right-sided hemicolectomy for children with high-risk NET of the appendix. Ultimately leading to the development of a consensus guideline and solid information for patients/parents. Plan of investigation In order to generate big data, an international historical cohort study is planned to compare complementary right-sided hemicolectomy with appendectomy alone for children with high-risk NET of the appendix. Results will be CONFIDENTIAL used by an international expert group to formulate treatment recommendations. Subsequently, these recommendations will be tested in an international Delphi study in order to develop a consensus guideline on the treatment of pediatric high-risk NET of the appendix. Expected results The cohort study will generate high quality information on overall/disease-free survival, recurrence, complications, costs, and hr-QoL. Recommendations made will be tested in a Delphi study; not only on the beneficial value of complementary right-sided hemicolectomy, but also on follow-up protocols and preoperative work-up. Ultimately, an international consensus guideline that redefines low-risk and high-risk NET of the appendix will be developed, leading to global de-escalation and uniformity of treatment. Relevance for childhood cancer Results are relevant for pediatric oncologists/surgeons/gastro-enterologists across the world, as redefining low-risk and high-risk patient groups, will lead to de-escalation of treatment. Furthermore, QoL of child and parents can be improved by reducing exposure to complications after complementary right-sided hemicolectomy, and by reducing the fear of recurrence by obtaining high-quality data to accurately inform patients and parents.

Official Title
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The Value of Complementary Right-sided Hemicolectomy for Pediatric Patients With High-risk Neuroendocrine Tumors (NETs) of the Appendix; Towards the Development of an (Inter-) National Consensus Guideline for the Pediatric Population.

Conditions
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Neoplasms, Appendix Cancer

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: All patients that were treated for an appendiceal NET before the age of 18 years old Time period: 1990-2020 Exclusion Criteria: Other appendiceal malignancies/tumours, for example: goblet cell carcinoma adenocarcinoma neuroendocrine carcinoma

Ages Eligible for Study
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Maximum Age: 17 Years

Sexes Eligible for Study
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All

Study Plan
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How is the study designed?
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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Disease free survival rate | defined as alive and free of recurrence of NET at telephone follow-up performed for this study purpose | cross-sectional design. follow-up will be done in 2023/2024 | 
| Recurrence rate | defined as histopathologically proven metastasis/residual tumor at appendiceal stump of NET after a disease free period | cross-sectional design. follow-up will be done in 2023/2024 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Overall survival rate | defined as alive at telephone follow-up performed for this study purpose | cross-sectional design. follow-up will be done in 2023/2024 | 
| Complications directly related to primary and secondary treatment divided into major and minor complications according to Clavien-dindo. | Complications include, but are not limited to: Intra-abdominal abscess, defined as a radiologically confirmed accumulation of purulent fluid in a walled-off space within the abdominal cavity. (Adhesive) bowel obstruction requiring readmission (diagnosis based on clinical signs and symptoms such as a history of constipation, nausea, vomiting and distended abdomen) Superficial Surgical Site Infection, as defined by the CDC criteria. (see table 1.) Deep Surgical Site Infection, as defined by the CDC criteria. | cross-sectional design. follow-up will be done in 2023/2024 | 
| Number of hospital readmission for complications related to treatment of NET | see title | cross-sectional design. follow-up will be done in 2023/2024 | 
| Length of hospital stay | initial and total length of stay | cross-sectional design. follow-up will be done in 2023/2024 | 
| number of imaging studies performed for follow-up of NET | ultrasound, computed tomography (CT), magnetic resonance imaging (MRI), octreotide scintigraphy, PET-CT | cross-sectional design. follow-up will be done in 2023/2024 | 
| Number of outpatient check-ups(regular visits / telephone call) for follow-up of NET | see title | cross-sectional design. follow-up will be done in 2023/2024 | 
| Health related Quality of Life at follow-up moment for this study | measured by the PedsQL(generic) | cross-sectional design. follow-up will be done in 2023/2024 | 
| Health related Quality of Life at follow-up moment for this study | measured by the QLQ-C30(generic) | cross-sectional design. follow-up will be done in 2023/2024 | 
| Health related Quality of Life at follow-up moment for this study | measured by the QLQ-GINET-21 questionnaire(disease specific) | cross-sectional design. follow-up will be done in 2023/2024 |