M1 medulloblastoma should be considered high risk at any age

Abstract

2016 Background: Metastatic (M) stage is an important prognostic marker in medulloblastoma. With current therapy including higher-dose craniospinal irradiation and dose intensive chemotherapy, older children with metastatic medulloblastoma have had improved survival. Some investigators have suggested that older children with M1 medulloblastoma be treated as average-risk patients. Additionally, the prognostic value of M1 disease in very young children has not been documented. Methods: We retrospectively reviewed the records of all newly diagnosed medulloblastoma patients treated at St. Jude Children’s Research Hospital from 1984 to 2006. Treatment generally included resection and chemotherapy. Older children received post-operative craniospinal and tumor bed irradiation; radiotherapy for younger children depended on treatment era and physician/family preference. We compared event-free and overall survival for patients with M1 disease to that of patients with M0 and M2/M3 disease for both age groups using the Kaplan-Meier method. Results: 286 patients were included. 56 were <3 years old at diagnosis and 230 were =3 years old. Event-free (EFS) and overall survival (OS) by age and M-stage are reported below. Within the younger group, a significant difference in 5-year EFS was detected among M-stage groups (p<0.002 by Mantel-Haenszel test); 5-year EFS for M0 (n=33), M1 (n=5), and M2/M3 (n=18) patients was 67%, 20%, and 22%, respectively. The difference in 5-year EFS by M-stage was also significant for older patients (p<0.0001); 5-year EFS for 154 M0, 13 M1, and 63 M2/M3 patients was 82%, 59%, and 42%, respectively. Results were similar for OS; differences in OS were significant for older (p<0.0001), but not younger (p=0.21) children. Conclusions: Children <3 years old with M1 medulloblastoma fared poorly in our small series. Survival for older children with M1 disease treated with higher-dose CSI was better than that of M2/M3 patients, but still less than optimal; our findings do not support reduction in therapy for either cohort. [Table: see text] No significant financial relationships to disclose.