LGG-50. PROFILE OF LOW GRADE GLIOMAS (LGGs) IN GREEK PATIENTS

Abstract

BACKGROUND/OBJECTIVES: Low-grade-gliomas(LGGs) encompass a heterogeneous set of tumors of different histologies. They are the most common type of pediatric brain tumors accounting almost 30-50% of them. This is the first attempt to describe characteristics of Greek-LGG-patients diagnosed in the largest Pediatric Brain Tumors National Center. DESIGN-METHODS: We performed a retrospective review of newly-diagnosed LGG-patients during 2015-2017. Gender, age, symptoms, location, leptomeningeal infiltration, histological type, BRAF-status, NF-status, management and outcome were analysed. RESULT(S): During the study period, 42 LGG-patients(22males) were diagnosed. Median age was 6.3years(range:40days-15.8years). Nearly 80% of the patients had symptoms of raised intracranial-pressure (headache/vomiting). The most common locations were: posterior-fossa(38.0%) followed by optic-pathway( 26.2%). Surgical intervention was possible in 30 patients(26 subtotal/total excision, 2 partial excision, 2 biopsy). Leptomeningeal infiltration at diagnosis was detected in 2 patients. Histological type was mostly astrocytoma (23pts, 54.8%), especially pilocytic type (69.5% of astrocytomas). NF1 was diagnosed in 23.8% of the patients. In 16non-NF1 patients RTPCR was performed for KIAA1549/BRAF-fusion and was positive in 5 patients and BRAFV600Emutation was detected in 3 patients. Treatment according to LGG2004-protocol was administered in 13 patients, of which 5 needed treatment-modification (3 due to carboplatin allergic reaction and 2 due to progressive disease) Radiotherapy was administered in 2 patients. One patient had a malignant transformation to glioblastoma multiforme, 16 months after initial diagnosis and died. At the end of treatment, visual and mobility problems were noted in two and one patients respectively. CONCLUSION(S): The most common histologic type was pilocytic astrocytoma. Overall survival was 97,6%. Our findings agree with those of internationally published studies.