Abstract
To investigate the prognoses associated with different locations of medulloblastoma (MB) in terms of survival through a case-control study and evaluate the prognostic factors for MB.The Surveillance, Epidemiology, and End Results database was used to identify MB patients diagnosed from 1975 to 2016. Each brainstem MB (bMB) patient was matched to a cerebellum MB (cMB) patient by propensity score matching based on age, sex, tumor size, extent of metastasis, extent of surgical resection, radiotherapy status and chemotherapy status. Univariate and multivariate analyses were performed to assess the effect of prognostic factors on overall survival. Ethical approval was not necessary as this study is based on a public database.A total of 172 bMB patients and 1417 cMB patients were included in the study. A total of 144 pairs of patients were matched to constitute the matched cohort. Within the matched cohort, the median survival times were 213 months and 96 months for cMB and bMB, respectively. Within the unmatched cohort, the median survival times were 111 months and 97 months for cMB and bMB, respectively. Brainstem location detrimentally affected the survival time of MB patients in both the matched cohort (hazard ratios =8.14, 95% confidence interval =5.98-11.08) and the unmatched cohort (hazard ratios =1.44, 95% confidence interval =1.20-1.74). Age <5 years and receipt of radiotherapy were favorable prognostic factors, whereas gross total resection, brainstem location and receipt of chemotherapy were unfavorable prognostic factors. Radiotherapy alone was associated with superior outcomes concerning adjuvant chemotherapy or radiotherapy.This study uncovers a survival advantage for cMB patients versus bMB patients. Additionally, prognostic factors include age, extent of surgical resection, and receipt of radiotherapy or chemotherapy. Radiotherapy after surgery and rational use of chemotherapy drugs are crucial for treatment of MB patients. Further studies of these prognostic factors are required to improve the survival time.