Factors possibly affecting prognosis in children with Wilms' tumor diagnosed before 24 months of age: A report from the Associazione Italiana Ematologia Oncologia Pediatrica (AIEOP) Wilms Tumor Working Group

Children with Wilms' tumor (WT) aged under 24 months (infants) have a better prognosis than older patients. Our aim was to study the epidemiology of this age group, with focus on the modality of diagnosis, tumor size, and association with malformations/syndromes, seeking to understand if any of these factors might be related to prognosis.

Infants diagnosed with WT between 2003 and February 2010 were evaluated. A query form was used to collect data on the modality of WT diagnosis (symptomatic or incidental), tumor volume, maximum diameter, site, and stage.

Data were collected for 117 of 124 WT infants registered. Twenty-four cases had an incidental diagnosis (ID) of renal mass, usually arising from an abdominal ultrasound performed for other reasons, and 93 had been diagnosed based on clinical signs/symptoms. The incidental cohort displayed unifocal disease, mean tumor diameter 5.52 cm, mean tumor volume 84.30 ml, and 14 patients showed associated malformations. Symptomatic patients had mean maximum tumor diameter of 10.18 cm, mean tumor volume of 451.18 ml, and six had associated malformations.

Our study showed that 20% of the infants had an ID of WT; they had a relatively smaller nonmetastatic tumor and a higher rate of malformations than infants of the symptomatically diagnosed group, but we did not detect any difference in age at diagnosis between the two groups. Conversely, we found a significant difference in the 5-year event-free survival rate (P = 0.018) between infants under 1 year (96%), more frequently associated with congenital malformations, and infants 1-2 years (80%).

Pediatric blood & cancer. 2017 Jun 09 [Epub ahead of print]

Paolo D'Angelo, Andrea Di Cataldo, Monica Terenziani, Gianni Bisogno, Paola Collini, Martina Di Martino, Fraia Melchionda, Clara Mosa, Marilina Nantron, Daniela Perotti, Giuseppe Puccio, Annalisa Serra, Serena Catania, Filippo Spreafico, AIEOP Wilms Tumor Working Group

Pediatric Oncology Unit, A.R.N.A.S. Ospedali Civico, Di Cristina e Benfratelli, Palermo, Italy., Pediatric Hematology and Oncology Unit, Catania University, Catania, Italy., Pediatric Oncology Unit, Fondazione IRCCS Istituto Nazionale Tumori, Milan, Italy., Pediatric Hematology and Oncology Unit, Pediatric Department, University of Padua, Padua, Italy., Soft Tissue and Bone Pathology, Histopathology, and Pediatric Pathology Unit, Fondazione IRCCS Istituto Nazionale Tumori, Milan, Italy., Pediatric Oncology Unit, Pediatric Department, II University, Naples, Italy., Pediatric Hematology and Oncology Unit "Lalla Seràgnoli", Bologna University, Bologna, Italy., Department of Hematology and Oncology, Istituto G. Gaslini, Genoa, Italy., Molecular Bases of Genetic Risk and Genetic Testing Unit, Department of Preventive and Predictive Medicine, Fondazione IRCCS Istituto Nazionale Tumori, Milan, Italy., Unit of Neonatology, AOUP "Paolo Giaccone", Palermo, Italy., Pediatric Hematology and Oncology Department, Ospedale Pediatrico Bambino Gesù, Rome, Italy.