PurposeAlthough studies regarding dental developmental disturbances after childhood cancer treatment have increased, they have many limitations. Studies analyzing the significance of independent clinical risk factors with regard to the dental health status are also rare. We aimed to investigate the risk factors for dental developmental disturbances, particularly severe disturbances, in childhood cancer survivors (CCS).Materials and MethodsOral examinations and retrospective reviews of medical and panoramic radiographs were performed for 196 CCS (mean age, 15.6 years). Cancer type, age at diagnosis, treatment modality, type and accumulated dose of administered drugs, and dose and site of radiation were recorded. Dental developmental disturbances were diagnosed using panoramic radiographs and graded for severity according to the Modified Dental Defect Index (MDDI). Descriptive statistics and multivariate analyseswere performed to determine the association between dental abnormalities and clinical factors.ResultsIn total, 109 CCS (55.6%) exhibited at least one dental anomaly, and the median value of MDDI was 2.5. Microdontia (30.6%) was the most prevalent anomaly, followed by tooth agenesis (20.4%), V-shaped roots (14.8%), and taurodontism (10.2%). Multivariate analysis revealed that a young age at diagnosis (≤ 3 years), a history of hematopoietic stem cell transplantation, the use of multiple classes of chemotherapeutic agents (≥ 4 classes), and the use of heavy metal agents were significant risk factors for severe dental disturbances.ConclusionCCS with any of the above risk factors for severe developmental disturbances should be comprehensively followed up to minimize adverse consequences to their dental development and preserve their future dental health.

Purpose Malignant peripheral nerve sheath tumors (MPNSTs) are a rare subtype of sarcoma that occur spontaneously or in association with neurofibromatosis type 1 (NF-1). This study aimed to clinically differentiate these types of MPNSTs. Materials and Methods The study reviewed 95 patients diagnosed with and treated for MPNST at Yonsei University Health System, Seoul, Korea over a 27-year period. The clinical characteristics, prognostic factors, and treatment outcomes of sporadic MPNST (sMPNST) and NF-1 associated MPNST (NF-MPNST) cases were compared. Results Patients with NF-MPNST had a significantly lower median age (32 years vs. 45 years for sMPNST, p=0.012), significantly larger median tumor size (8.2 cm vs. 5.0 cm for sMPNST, p < 0.001), and significantly larger numbers of imaging studies and surgeries (p=0.004 and p < 0.001, respectively). The 10-year overall survival (OS) rate of the patients with MPNST was 52±6%. Among the patients with localized MPNST, patients with NF-MPNST had a significantly lower 10-year OS rate (45±11% vs. 60±8% for sMPNST, p=0.046). Univariate analysis revealed the resection margin, pathology grade, and metastasis to be significant factors affecting the OS (p=0.001, p=0.020, and p < 0.001, respectively). Multivariate analysis of the patients with localized MPNST identified R2 resection and G1 as significant prognostic factors for OS.Conclusion NF-MPNST has different clinical features from sMPNST and requires more careful management. Further study will be needed to develop specific management plans for NF-MPNST.

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Atypical teratoid/rhabdoid tumor (ATRT) is a highly aggressive malignancy with peak incidence in children aged less than 3 years. Standard treatment for CNS ATRT in children under the age of 3 years have not been established yet. The objective of this study was to analyze characteristics and clinical outcomes of ATRT in children aged less than 3 years. Materials and Methods A search of medical records from 7 centers was performed between January 2005 and December 2016. Results Forty-three patients were enrolled. With a median follow-up of 90 months, 27 (64.3%) patients showed at least one episode of disease progression (PD). The first date of PD was at 160 days after diagnosis. The 1-and 3-year progression free survivals (PFS) were 51.2% and 28.5%, respectively. The 1-and 3-year overall survivals were 61.9% and 38.1%, respectively. The 3year PFS was improved from 0% in pre-2011 to 47.4% in post-2011. Excluding one patient who did not receive any further therapy after surgery, 27 patients died due to PD (n = 21), treatment-related toxicity (n = 5), or unknown cause (n = 1). In univariate analysis, factors associated with higher 3-year PFS were no metastases, diagnosis after 2011, early adjuvant radiotherapy, and high dose chemotherapy (HDCT). In multivariate analysis, the use of HDCT and adjuvant radiotherapy remained significant prognostic factors for PFS (both p<0.01). Conclusion Aggressive therapy including early adjuvant radiotherapy and HDCT could be considered to improve outcomes of ATRT in children under the age of 3 years.