Prognostic factors in high-grade pediatric osteosarcoma among children and young adults: Greek Nationwide Registry for Childhood Hematological Malignancies and Solid Tumors (NARECHEM-ST) data along with a systematic review and meta-analysis.

The 5-year overall survival of children and adolescents with osteosarcoma has been in plateau during the last 30 years. The present systematic review (1976-2023) and meta-analysis aimed to explore factors implicated in the prognosis of children and young adults with high-grade osteosarcoma. Original studies including patients ≤30 years and the Nationwide Registry for Childhood Hematological Malignancies and Solid Tumors (NARECHEM-ST) data (2010-2021) referred to children ≤14 years were analysed. Individual participant data (IPD) and summary estimates were used to assess the n-year survival rates, as well as the association of risk factors with overall survival (OS) and event-free survival (EFS). IPD and the n-year survival rates were pooled using Kaplan-Meier and Cox regression models, and random effects models, respectively. Data from 8412 patients, including 46 publications, NARECHEM-ST data, and 277 IPD from 10 studies were analysed. The summary 5-year OS rate was 64% [95% confidence interval (95%CI): 62%-66%, 37 studies, 6661 patients] and the EFS was 52% (95%CI: 49%-56%, 30 studies, 5010 patients). The survival rates generally differed in the pre-specified subgroups. Limb-salvage surgery showed a higher 5-year OS rate (69%) versus amputation (47%). Good responders had higher OS rates at 3 years (94%) and 5 years (81%), compared to poor responders at 3 years (66%), and 5 years (56%). Patients with metastatic disease had a higher risk of death [Hazard Ratio (HR): 3.60, 95%CI: 2.52, 5.15, 11 studies]. Sex did not have an impact on EFS (HR females/males: 0.90, 95%CI: 0.54, 1.48, 3 studies), whereas age>18 years seems to adversely affect EFS (HR 18+/<10 years: 1.36, 95%CI: 1.09, 1.86, 3 studies). Our results summarize the collective experience on prognostic factors of high-grade osteosarcoma among children and young adults. Poor response to neoadjuvant chemotherapy and metastatic disease at diagnosis were confirmed as primary risk factors of poor outcome. International collaboration of osteosarcoma study groups is essential to improve survival.

Inferior Vena Cava agenesis presenting as deep vein thrombosis in an eight year-old girl.

Agenesis of vena cava inferior (AVCI) is a rare congenital malformation with a prevalence of 0.0005-1% in the general population. High level of suspicion is required in young patients with deep vein thrombosis (DVT), particularly bilateral. We present an 8-year-old girl with AVCI presenting as bilateral lower extremity DVT and a review of the literature in pediatric cases with AVCI and DVT.

Survival patterns of childhood neuroblastoma: an analysis of clinical data from Southern-Eastern European countries.

The prognosis of children with neuroblastoma (NBL) can be dismal with significant variations depending on the stage and biology of the tumor. We assessed the event-free (EFS) and overall (OS) survival using harmonized data from three Southern-Eastern European (SEE) countries. Data for 520 incident NBL cases (2009-2018) were collected from Greece, Slovenia and Russia. Kaplan-Meier curves were fitted, and EFS/OS were derived from Cox proportional models by study variables including the protocol-based risk-group (low/observation, intermediate, high). Over one-third of cases were coded in the high-risk group, of which 23 children (4.4%) received treatment with anti-ganglioside 2 (GD2) mAb. Survival rates were inferior in older (OS 5-year; 1.5-4.9 years: 61%; EFS 5-year; 1.5-4.9 years: 48%) compared to children younger than 1.5 years (OS 5-year; <1.5 years: 91%; EFS 5-year; <1.5 years: 78%). Predictors of poor OS included stage 4 (hazard ratio, HR OS : 18.12, 95% confidence intervals, CI: 3.47-94.54), N-myc amplification (HR OS : 2.16, 95% CI: 1.40-3.34), no surgical excision (HR OS : 3.27, 95% CI: 1.91-5.61) and relapse/progression (HR OS : 5.46, 95% CI: 3.23-9.24). Similar unfavorable EFS was found for the same subsets of patients. By contrast, treatment with anti-GD2 antibody in high-risk patients was associated with decreased risk of death or unfavorable events (HR OS : 0.11, 95% CI: 0.02-0.79; HR EFS : 0.19, 95% CI: 0.07-0.52). Our results confirm the outstanding prognosis of the early NBL stages, especially in children <1.5 years, and the improved outcomes of the anti-GD2 treatment in high-risk patients. Ongoing high-quality clinical cancer registration is needed to ensure comparability of survival across Europe and refine our understanding of the NBL biology.