An International Study on Pediatric Patients With Rare Tumors.

There are some very rare tumors (with an annual incidence of less than two per million children) that can affect children and adolescents. These neoplasms include a wide variety of cancers; some are rare at any age, while others are typical of adults but very rare in children. Due to their rarity, studies have so far been scarce, often lacking univocal diagnostic criteria, and more information is needed to improve treatment outcomes.

The aim of this study is to collect epidemiological, clinical, biological, radiological and treatment data on children and adolescents with rare cancers in order to improve our understanding of these tumors and how their clinical and biological characteristics affect treatment outcomes.

Due to the rarity of these malignancies, international collaboration is necessary to collect sufficient data on each tumour type.

While the investigators are not proposing specific treatments, the data collected will inform recommendations for the diagnosis and treatment of patients.

The PARTNER Study is an observational, prospective study. It is sponsored by Padua University Hospital AOUP (Italy), and all European centres collaborating with the EXPeRT group have been invited to participate. It is a non-profit study, meaning it has no commercial purpose, only the aim of improving knowledge and treatment for children with rare cancers. PARTNER activities are supported in different countries by national funds, as well as by the European Commission through the European Reference Network for Paediatric Oncology (ERN PaedCan). Please visit https://paedcan.ern-net.eu/ for more information.

Primary outcomes

• Epidemiology [through study completion, an average of 1 year]: Evaluate the number of patients (aged 0-18 years) with different Very Rare Tumors in the different countries: observed cases will be compared with expected cases.
• Use of International Recommendations [through study completion, an average of 1 year]: The study aims to measure the number of patients treated for different neoplasms in different countries, and the proportion of those treated in accordance with the International Recommendations.
• Survival of children and adolescents (0-18 years) affected by Very Rare Tumors [through study completion, an average of 1 year]: The study will correlate the clinical characteristics of the tumor (size, site, extension) with the treatment, the risk of recurrence and survival.

Sex: All, ages: 0 Years to 18 Years

Inclusion Criteria:

* Children and adolescents (age 0-18 years) with a primary or relapsed Very Rare Tumor diagnosed and/or treated in a participating country/center.
* Written informed consent from the patient and/or the parent/legal guardian

Exclusion Criteria:

* Absence of Written informed consent from the patient and/or the parent/legal guardian

• Orbach D, Ferrari A, Schneider DT, Reguerre Y, Godzinski J, Bien E, Stachowicz-Stencel T, Surun A, Almaraz RL, Dragomir M, Jani D, Ami TB, Roganovic J, Brecht IB, Ladenstein R, Bisogno G. The European Paediatric Rare Tumours Network - European Registry (PARTNER) project for very rare tumors in children. Pediatr Blood Cancer. 2021 Jun;68 Suppl 4:e29072. doi: 10.1002/pbc.29072. Epub 2021 Apr 29. PMID 33913610

• Gianni Bisogno, MD, Principal investigator, Azienda Ospedale Università Padova - Italy