Prognostic factors in medulloblastoma, including DNA ploidy.

PURPOSEDNA ploidy status, completeness of surgical resection, use of chemotherapy, adequacy of radiation therapy, metastatic stage, sex, and age at diagnosis were evaluated as predictors of relapse in 58 patients with cerebellar medulloblastoma.METHODSFlow cytometry (FCM) and/or image analysis (IA) were used to characterize tumor DNA ploidy. Twelve tumors (21%) were found to be aneuploid, 11 (19%) tetraploid, and 35 (60%) diploid.RESULTSThe most significant predictors of relapse in univariate analyses were the adequacy of radiation (> or = 50 Gy) (P = .02), metastatic staging (P = .05), completeness of resection (P = .085), and DNA ploidy status (diploid/tetraploid v aneuploid; P = .11). When the 52 patients who received > or = 50 Gy were included in a multivariate Cox model analysis, those with diploid/tetraploid tumors had fewer recurrences than those with aneuploid tumors (relative risk, 0.33; 95% confidence interval, 0.12 to 0.89; P = .03). Patients with complete resections (P = .07), or with stage M0...