MEDB-20. The outcome of medulloblastoma patients in the 2010-2018 period in Children’s Hospital Zagreb

Abstract

This study aims to present the key characteristics of the medulloblastoma patients treated in Children’s Hospital Zagreb and the University Hospital Center Zagreb in Croatia between 2010-2018 period. Croatia has around 145 newly diagnosed pediatric oncology patients annually, including approximately 30 neurooncology patients. We have conducted the retrospective analysis of the hospital records and have collected data on 32 medulloblastoma patients (9 females, 23 males). At the time of diagnosis, the median age was 5,62 (range 0.85-15.86). Before the treatment commencement, we determined conventional risk factors and stratified our patients into standard and high-risk groups (17 standard risk patients, 15 high risk). Qualification for high-risk included metastatic disease, postoperative local residual disease greater than 1.5 cm2, confirmed myc/nmyc amplification in the tumor tissue, and the large cell/anaplastic tumor subtype (p53 positive). The methods of molecular diagnostics were not available at the time. The patients that received solely postoperative chemotherapy were younger than three years. Children younger than five suffering from desmoplastic tumor subtype also received intraventricular methotrexate (Ommaya). High-dosage chemotherapy with autologous stem cell transplantation failed to treat metastatic infant medulloblastoma (2 patients with a lethal outcome). The rest of the patients received craniospinal irradiation, followed by adjuvant chemotherapy. According to the Kaplan-Meier survival analysis, the 5-year overall survival is 65,6 % (40% in the high-risk group and 88% in the standard-risk group). In addition, 5-year event-free survival is 59,4 % (33% in the high-risk group and 82,4% in the standard-risk group). None of the patients developed a secondary malignant disease during the follow-up. Conventional characteristics that determine standard-risk group affiliation are reliable, leading to a satisfactory treatment outcome. The results of the high-risk group treatment are poor necessitating modification treatment approach within clinical trials.