Do expression profiles of 151 pediatric low-grade gliomas reveal molecular differences associated with location and histological subtype?
Expression profiling of PLGGs reveals significant differences associated with tumor location, histology, and BRAF genomic status. Supratentorial PAs, in particular, are enriched in inflammatory pathways that appear to be tumor-related.
Excellent locoregional control was obtained in T1-T3 tonsillar fossa and/or SP tumors. The rate at 10 years was 84% (BT group) vs. 78% (surgery group). However, adverse late side effects were not negligible. In addition to modality-specific side effects (ulcer/trismus), both treatment groups were significantly affected by xerostomia. Only 6 recurrences (4%) were observed in the 149 electively treated contralateral necks, and no relapses were seen in the 29 untreated contralateral necks. We, therefore, suggest that it is not necessary to treat the contralateral neck, unless the tumor extends beyond the midline of the soft palate (uvula) or beyond the lateral one-third of the ipsilateral base of the tongue. Moreover, with the currently available CT-based neck level definitions, more conformal contours (i.e., tighter boundaries) around the clinical target volume can be designed. In this way, critical structures such as the temporomandibular joint and part of the pterygoid muscles can be avoided more easily. Also, when using highly conformal treatment techniques (e.g., intensity-modulated RT), one can further reduce the dose to the major salivary glands and oral mucosa. We believe these measures will lead to less trismus and less xerostomia.