AbstractBackground Very rare tumors (VRT) in children and adolescents have such a low
incidence that until recently, they have not been integrated into the clinical
and scientific network of pediatric oncology. Data is very limited and
consistent treatment strategies are missing. Thus, VRTs are classic orphan
diseases. To counteract this problem, the Arbeitsgemeinschaft für
Seltene Tumorerkrankungen in der Pädiatrie (STEP) was founded. Here we
report on patient recruitment during the first 10 years. Patients Patients aged
up to 18 years and not included in any other clinical trial or GPOH registry
were included in this analysis. Methods Data was collected from 2008 to 2018 by
means of a standardized form. The recorded diagnoses were descriptively analyzed
focusing on histology, localization, and year of report. Results A total of 623
patients with VRTs were registered. During 2008–2014, the annual number
of registrations was around 40 and is around 90 since 2015. Most frequent
diagnoses included tumors of the skin (n=150), tumors of the
gastrointestinal tract (n=102), tumors of the gonads (n=77), the
ENT region (n=68), and miscellaneous tumors (n=107).
Discussion With the establishment of central structures for clinical
consultation and documentation of VRTs, the number of registrations increased.
Comprehensively, VRTs are as common as other classic pediatric oncology tumors,
but extremely heterogeneous in terms of localization, histology, and prognosis.
By a centralized and complete registration and analysis of VRTs, also in
collaboration with international partners, it is possible to develop treatment
strategies and thus greatly increase treatment quality.