Introduction: Partial hepatectomy in children with primary hepatic malignancies has a complication rate as high as 30%. This has a negative effect on outcomes. We organized a multidisciplinary team (MDT) dedicated to the care of these patients to lower complication rates and improve outcomes. Methods: A retrospective chart review was completed for all patients < 18 years of age who underwent liver resection at our institution between 2002 and 2019 for primary hepatic cancer. Demographic, intraoperative, postoperative, pathologic, and outcome data were analyzed for perioperative complications using the CLASSIC and Clavien-Dindo (CD) scales, event-free survival (EFS) and overall survival (OS). Results: Ten (13%) of 73 patients experienced a major perioperative complication (CLASSIC or CD > 3); two (3%) died within 30 days of surgery. After the implementation of a dedicated MDT in 2014, the major perioperative complication rate decreased from 18% to 10%, and rates for all complications dropped from 52% to 20% (p=0.005). Older patient age (median 62 months vs. 50 months, p=0.05) and the presence of pulmonary metastases at diagnosis (p=0.01) were associated with increased rates of major perioperative complications. Among patients with a hepatoblastoma (n=62), the presence of a major perioperative complication was associated with a worse EFS (HR=5.45, p=0.03) on multivariate analysis. Patients treated following MDT implementation had improved EFS (HR=0.18, p=0.04). Conclusions: Our results demonstrate that, for children with primary liver malignancies, a MDT can decrease the rate of complications of liver resection and improve the oncological outcome of hepatoblastoma.

Background: Pediatric papillary thyroid carcinoma (PTC) is clinically and biologically distinct from adult PTC. We sequenced a cohort of clinically-annotated pediatric PTC cases enriched for high-risk tumors to identify genetic alterations of relevance for diagnosis and therapy. Methods: Tumor DNA and RNA were extracted from FFPE tissue and subjected to next generation sequencing (NGS) library preparation using a custom 124 gene hybridization capture panel and the 75 gene Archer Oncology Research Panel, respectively. NGS libraries were sequenced on an Illumina MiSeq. Results: Thirty-six pediatric PTC cases were analyzed. Metastases were frequently observed to cervical lymph nodes (29/36, 81%), with pulmonary metastases less commonly found (10/36, 28%). Relapsed or refractory disease occurred in 18 patients (18/36, 50%). DNA sequencing revealed targetable mutations in 8 of 31 tumors tested (26%), most commonly BRAF p.V600E (n=6). RNA sequencing identified targetable fusions in 13 of 25 tumors tested (52%): RET (n=8), NTRK3 (n=4), and BRAF. Mutually-exclusive targetable alterations were discovered in 15 of the 20 tumors (75%) with both DNA and RNA analyzed. Fusion positive PTC was associated with multifocal disease, higher tumor staging, and higher American Thyroid Association (ATA) risk levels. Both BRAF V600E mutations and gene fusions were correlated with the presence of cervical metastases. Conclusions: Targetable alterations were identified in 75% of pediatric PTC cases with both DNA and RNA evaluated. Inclusion of RNA sequencing for detection of fusion genes is critical for evaluation of these tumors. Patients with fusion positive tumors were more likely to have features of high-risk disease.