Photobiomodulation with a combination of two wavelengths in the treatment of oral mucositis in children: The PEDIALASE feasibility study.

Photobiomodulation is recommended in adults for the prevention of mucositis induced by cervicofacial irradiation or pre-transplant chemotherapy. The results of pediatric studies are promising but this support treatment is still underused. The objective was to conduct a feasibility study in the pediatric hematology-oncology unit at X Children's Hospital. Extra- and intraoral scans were performed a minimum of three times every 2 days for grade 2 or higher mucositis in children (median age, 8.6 years) using the Oncolase laser (Biophoton, Saint Alban, France), with a combination of two wavelengths (635 and 815nm). The effect of the laser on mucositis grade, pain, the child's tolerance, and the time dedicated to this care were also evaluated. The success of the procedure was 77% in 1 year, with the inclusion of 84% of the patients (n=22) and 146 laser treatment sessions (median of four per episode of mucositis). We observed excellent tolerance and pain relief with a gain of two points on the VAS and the HEDEN mucositis scale. This study shows that photobiomodulation that incorporates two application modes (intra- and extraoral) through the combination of two wavelengths is feasible when integrated into the care of a pediatric hematology-oncology department and is perfectly tolerated, even by young children. Along with oral hygiene and analgesic management, it alleviates pain associated with oral mucositis.

NUP98 is rearranged in 3.8% of pediatric AML forming a clinical and molecular homogenous group with a poor prognosis.

Pediatric acute myeloid leukemia (AML) is a rare disease whose prognosis is highly variable according to factors such as chromosomal abnormalities. Recurrent genomic rearrangements are detected in half of pediatric AML by karyotype. NUcleoPorin 98 (NUP98) gene is rearranged with 31 different fusion partner genes. These rearrangements are frequently undetected by conventional cytogenetics, as the NUP98 gene is located at the end of the chromosome 11 short arm (11p15). By screening a series of 574 pediatric AML, we detected a NUP98 rearrangement in 22 cases (3.8%), a frequency similar to CBFB-MYH11 fusion gene (4.0%). The most frequent NUP98 fusion gene partner is NSD1. These cases are homogeneous regarding their biological and clinical characteristics, and associated with bad prognosis only improved by bone marrow transplantation. We detailed the biological characteristics of these AML by exome sequencing which demonstrated few recurrent mutations (FLT3 ITD, WT1, CEBPA, NBPF14, BCR and ODF1). The analysis of the clonal structure in these cases suggests that the mutation order in the NUP98-rearranged pediatric AML begins with the NUP98 rearrangement leading to epigenetic dysregulations then followed by mutations of critical hematopoietic transcription factors and finally, activation of the FLT3 signaling pathway.