(1) Background: Gastric carcinoma is an exceptionally rare tumor in childhood. Little is known about the etiology, epidemiology, and clinical features of pediatric gastric carcinomas. This analysis aimed to fill this gap by increasing knowledge about the occurrence of gastric carcinoma in childhood. (2) Material and methods: Data from gastric carcinoma cases diagnosed between 2000 and 2017/2018 were retrieved from the Surveillance, Epidemiology, and End Results Program (SEER) and the German Center for Cancer Registry Data. Data from patients <20 years of age were analyzed for patient- and tumor-related characteristics. In addition, clinical data from patients with gastric carcinoma registered in the German Registry for Rare Pediatric Tumors (STEP) were analyzed for diagnostics, therapy, and outcome. (3) Results: Ninety-one cases of gastric carcinoma, mainly in adolescents, were identified in the epidemiologic cancer registries. Among patients with recorded staging data, advanced tumor stages were common (66.7%). Within the follow-up period covered, 63.7% of patients with clinical follow-up data died. Eight pediatric patients with gastric carcinoma were enrolled in the STEP registry, among whom two were patients with hereditary CDH1 mutations and another was a patient with Peutz−Jeghers syndrome. Three patients were found to have distinctly decreased immunoglobulin concentrations. All four patients in whom complete resection was achieved remained in remission. Three of the other four patients died despite multimodal therapy. (4) Conclusions: A combination of Helicobacter pylori infection and tumor predisposition and/or immunodeficiency appears to promote the development of gastric carcinoma in childhood. While patients with localized disease stages have a good chance of achieving durable remission through complete resection, patients with stage IV carcinomas face a dismal prognosis, highlighting the need to develop new strategies such as mutation-guided treatments.

Growth and development of the human body and its organs are finely tuned processes that are continuously regulated by numerous genes. Genetically determined defects of this fine regulation can result in growth disorders, e.g. in small or large stature syndromes or in organ malformations. Particularly in cases of germline defects, they can also lead to an increased risk for the development of cancer. In total, more than 50 cancer predisposition syndromes have been identified so far. This review article exemplarily presents three cancer predisposition syndromes relevant to pediatrics, neurofibromatosis type 1, Beckwith-Wiedemann syndrome, and DICER1 syndrome. Screening of these patients is of crucial importance and should be adapted to the expected tumor spectrum. The aim is to detect the development of malignant tumors at an early stage, with better prognosis and less treatment requirements. In addition, follow-up must take into account the possible development of secondary tumors or other secondary diseases. Knowledge of the oncological and nononcological aspects of these cancer predisposition syndromes is therefore a prerequisite for an appropriate and comprehensive care of these patients and thus relevant for pediatric oncologists, pediatric specialists as well as general pediatricians.

Wachstum und Entwicklung des menschlichen Körpers und seiner Organe sind fein abgestimmte Prozesse, die kontinuierlich durch zahlreiche Gene reguliert werden. Genetisch bedingte Defekte dieser Feinregulation können sich klinisch zum einen in Wachstumsstörungen, z. B. in Klein- oder Großwuchssyndromen, oder in Organfehlbildungen manifestieren. Zum anderen können sie, insbesondere bei Keimbahndefekten, ein erhöhtes Risiko für die Entwicklung einer Krebserkrankung bedingen. Insgesamt sind mehr als 50 Erkrankungen mit einer erhöhten Krebsprädisposition bekannt. In dieser Übersicht werden beispielhaft 3 für die Pädiatrie relevante Krebsprädispositionserkrankungen, die Neurofibromatose Typ 1, das Beckwith-Wiedemann-Syndrom und das DICER1-Syndrom, vorgestellt. Von entscheidender Bedeutung ist ein auf das zu erwartende Tumorspektrum angepasstes Screening dieser Patienten. Ziel ist es, die Entstehung bösartiger Tumoren frühzeitig erkennen zu können und dadurch mit weniger Therapieeinsatz eine bessere Prognose zu ermöglichen. Darüber hinaus muss die Krebsnachsorge die mögliche Entwicklung von Folgetumoren oder anderen Folgeerkrankungen in den Blick nehmen. Kenntnisse der onkologischen und nichtonkologischen Aspekte dieser Krebsprädispositionserkrankungen sind die Voraussetzung für eine angemessene ganzheitliche Betreuung dieser Patienten und damit für Kinderonkologen, pädiatrische Spezialisten sowie Allgemeinpädiater relevant.