For a study, it was determined that although pilocytic astrocytomas (PAs) had a generally good prognosis, they developed or recur following eThe usefulness of histological criteria (described below) or BRAF abnormalities in terms of prognosis is unknown. The researchers determined whether pediatric PAs’ genetic and histological characteristics had any predictive value. The histological and genetic aspects and the outcomes of patients treated with a WHO grade I PA at a single hospital were studied. “WHO grade I PA with elevated proliferative index” was an example of a “histopathological qualification.” Gene fusions and point mutations were examples of BRAF mutations. Neurofibromatosis type 1 patients were omitted from the study.

About 222 patients were studied (51% female, mean age 9.6 years). The cerebellum/fourth ventricle (51%) was the most common site for tumors, followed by the optic pathway/hypothalamus (15%), brainstem (12%), and cerebral cortex (11%). BRAF mutations were found in 56 of the 77 patients who were examined (73%). In 27 patients, histopathological qualifiers were found (14%). Resection was performed on 197 patients (89%), of whom 41 (21%) had tumor progression or recurrence following resection. Histopathologic characteristics (P=0.36) or BRAF changes (P=0.77) were not linked to tumor progression or recurrence. Progression or recurrence was not predicted by Ki-67 proliferative indices (P=0.94). BRAF mutations, notably KIAA1549 fusions, were linked to the tumor site in the cerebellum/fourth ventricle (P<0.0001) and younger patient age (P=0.03). Researchers reduced the risk of progression and recurrence in patients who received a gross-total resection (P<0.0001). In pediatric PAs, histopathological features/qualifiers and BRAF mutations were not linked to tumor recurrence/progression. The only factor studied that predicted prognosis was the degree of resection.