A retrospective analysis of the demographic and clinical features, treatment regimens and survival of medulloblastoma patients

Central nervous system tumors are the second most common childhood cancer in developed countries and the third most common cancer in our country, after leukemia and lymphoma. Medulloblastoma comprises 20% of CNS tumors between 0-14 years and 6% of CNS tumors between 15-19 years. In this retrospective study, we aimed to evaluate the clinical characteristics and survival rates of 44 medulloblastoma patients, who were treated at Akdeniz University Medical Faculty Pediatric Hematology-Oncology Department between January 1999 and December 2016. Mean age of patients at diagnosis was 8.04 years and the male/female ratio was 1,09. Four patients (9,09%) were younger than 3 years at diagnosis. 14 patients (%31,8) had seeding metastasis. Total resection (n=34), subtotal resection (N=9) and biopsy (n=1) were performed in these patients. Patients who were older than 3 years at diagnosis received craniospinal radiotherapy. All patients received chemotherapy and the most common chemotherapy regimen was a combination of CCNU, CDDP and VCR. Mean follow-up duration was 66.05 ± 64,39 months and median follow-up duration was 44.0 months (5- 273). Five year overall survival rate was 67,3% ± 8.1 and 5-year event free survival rate was 58,8% ± 8,2. Ten patients (22,7%) had a recurrence of the disease and mean time to relapse was 23,20 months. Two year overall and event-free survival rates for patients younger than 3 years old at diagnosis were significantly lower than those who were older (50,0% ± 25.0 vs. 87,0% ± 5.4 (log rank= 0,001) and 25,0% ± 21,2 vs. 69,2% ± 9.3 (log rank= 0,014), respectively). Patients who didn't have spinal seeding metastasis at diagnosis had a significantly higher 5-year overall survival rate compared to those who did (75,5% ± 9.0 vs. 50,3% ± 15.5 (log rank= 0,048)). Patients who were in the standard risk group had a significantly higher 5-year overall survival rate than those in the high-risk group (87,2% ± 8,6 vs. 54,9% ± 11,1 (log rank= 0,047)). There have been significant changes in medulloblastoma's molecular and histopathological classification. The therapeutic approaches are expected to change in light of these classifications. Treatment of high-risk patients is still a difficult issue. Analysis of our patient data will be guiding us in our future patient follow-ups.