PAEDIATRIC-11 EPIDEMIOLOGY OF PINEALOBLASTOMA IN CAPE TOWN, SOUTH AFRICA

OBJECTIVE To compare the experience with pinealoblastoma (PB) of the neuro-oncology services of the University of Cape Town to the WHO 2021 classification. METHODS A retrospective analysis was performed on folders of patients diagnosed at Red Cross War Memorial Children’s Hospital and Groote Schuur Hospital from 2000-2022. Routine molecular testing is not available nor is testing for DICER mutations. Patients with PB associated with retinoblastoma (RB) were assumed to be Rb1-altered and were treated with ophthalmic local control and chemotherapy, and those without associated RB (assumed to be non-Rb1-altered) were mostly treated with surgery, chemotherapy and craniospinal radiotherapy. Convenience sampling was performed by age with respect to disease characteristics and outcome to try and disaggregate miRNA-processing-altered-1 and -2 from MYC/FOXR2-altered PB. RESULTS Twenty-five patients were identified, 6 with Rb1-altered PB, aged 0.33-1.88 years (median 0.79) and 19 with non-Rb1-altered PB, aged 0.17-12.99 years (median 6.23). The whole cohort was balanced in terms of gender but there were slightly more girls (11) than boys (8) among the non-Rb1-altered PBs. One of these children was a 5-year-old boy with DICER syndrome who was identified through family screening. One Rb1-altered PB had metastatic disease outside the pineal gland. Among the non-Rb1-altered PBs 47% had metastases, 0% of those under 3 years, 40% of those aged 3-9 years and 80% of those older than 9 years. Estimated 5-year OS for the whole group was 49%, 50% for Rb1-altered PB and 49% for non-Rb1-altered PBs. OS by age among non-Rb1-altered PBs was 0% for 0-3 years, 90% for 3-9 years and 20% for those older than 9 years. CONCLUSION DICER testing and molecular typing would be very useful in helping to stratify our non-Rb1-altered PBs, both for prognostication and to allow consideration of high-risk strategies. Multi-disciplinary treatment of PB in LMIC is essential.