Abstract 3463: Treatment of young children with localized medulloblastoma by chemotherapy alone: Final results of the prospective multicenter trial HIT 2000 confirming the prognostic impact of histology

Proceedings: AACR 102nd Annual Meeting 2011‐‐ Apr 2‐6, 2011; Orlando, FL Background: This study was designed to confirm the previously observed favorable survival rates and prognostic factors in young children with non-metastatic medulloblastoma (MB) treated by postoperative chemotherapy alone. Methods: Patients diagnosed between January 2001 and December 2005 and younger than 4 years received three cycles of postoperative systemic multiagent chemotherapy and intraventricular methotrexate. In case of complete remission, treatment was terminated after two additional cycles of chemotherapy. Otherwise secondary surgery, radiotherapy and consolidation chemotherapy were recommended. Results: The 5-year event-free survival (EFS) and overall survival (OS) (±SE) rates of 45 patients were 57 ± 8% and 80 ± 6% (median follow-up: 4.5 years, median age: 2.5 years). Nineteen patients with desmoplastic / nodular MB variants had better EFS and OS (5-year rates: 90 ± 7% and 100 ± 0%) compared to 23 patients with classic MB (30 ± 11% and 68 ± 10%; p< 0.001 for EFS, p=0.008 for OS). Five-year EFS and OS rates of 3 children with anaplastic MB were 33 ± 27%. Desmoplastic / nodular histology was an independent prognostic factor for EFS. Twenty-nine of 30 (97%) patients without postoperative residual tumor remained in continuous complete remission. Conclusions: Our results confirm histology of MB variants as a strong prognostic factor in this age-group. Sustained tumor control and favorable survival rates can be achieved by this chemotherapy regimen in young children with desmoplastic / nodular MB variants. For children with non-desmoplastic / non-nodular MB variants, where predominantly local relapses lead to less favorable survival rates, local radiotherapy has been introduced after chemotherapy since 2006. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3463. doi:10.1158/1538-7445.AM2011-3463