GC-14: ENDOCRINOPATHY AFTER INTRACRANIAL GERM CELL TUMOURS (IGCT) IS DISEASE NOT RADIATION- RELATED: TWO DECADES OF SURVEILLANCE IN A LARGE TERTIARY PAEDIATRIC COHORT

BACKGROUND: Childhood ICGT are rare, malignant tumours of the pituitary stalk and pineal region, highly curable (>90%) by multimodal therapies. Neuroendocrine outcomes are thus important. Deficits increase over time but, without longitudinal studies, it remains unclear whether they are primarily disease or treatment-related. OBJECTIVE AND HYPOTHESES: To determine by longitudinal retrospective analysis in survivors, tumour- and treatment-related factors for neuroendocrine morbidity including tumour location and volume. METHOD: We searched in electronic document libraries at our split-site centre (UCLH/GOSH) from 01/1995 until 01/2015 and excluded cases where an IGCT was not confirmed by MRI and/or histopathology reports. Endocrinopathies over time were analysed by Kaplan Meir statistics and correlated with tumour location and 3D volume using novel software- ITK-SNAPv3.2.0 (www.itksnap.org), and treatment type. RESULTS: 30 patients were identified and diagnosed at median age of 9.52 (5.83-14.57) years, pineal tumours presenting with shorter symptom duration (pineal vs pituitary:0.33 vs 0.67 years, p = 0.101). 76.7% had presenting visual disturbance, 57.1% had 2 or more anterior pituitary deficits and 66.7% had central DI. All (100%) pituitary cases eventually developed CDI (vs 0% pineal) and 2 or more anterior pituitary deficits, including 100% GHd (vs 16.7% pineal). All surgical patients developed panhypopituitarism + CDI, but only 50% of irradiated patients, (neuraxial(CSI) or ventricular (VI) + chemotherapy), developed new anterior pituitary deficits. CONCLUSION: Contrary to prevailing dogma, late evolving endocrinopathy is predicted by pituitary disease at diagnosis rather than imposed pituitary radiation and escalated by surgery. Thus substituting CSI with VI + chemo will not avoid this complication and may add peripheral toxicity (ototoxicity, nephrotoxicity, gonadotoxicity).