Prognostic importance of DNA ploidy in medulloblastoma of childhood.

The deoxyribonucleic acid (DNA) content of 53 medulloblastomas was analyzed by means of flow cytometry and compared with the clinical and histological findings in the host patients. Analysis of DNA showed that about half of the tumors were diploid and the other half were aneuploid. More diploid tumors were found among patients of a young age, but the difference was without statistical significance. Cellular differentiation of the tumor did not correlate with DNA ploidy. No correlation was found between Chang's T staging system and the DNA ploidy, whereas the M staging correlated with the ploidy; diploid medulloblastomas had a greater tendency to metastasize than aneuploid medulloblastomas (p = 0.0003). Four-year survival was compared with the extent of resection and DNA ploidy. The patients with total resection and aneuploid medulloblastoma had a better prognosis than those with subtotal resection and diploid tumor (p = 0.001). There was only one survivor among eight patients with subtotally resected diploid medulloblastomas, while all of the seven patients with totally resected aneuploid medulloblastomas survived. Comparison of the G0/G1 phase fraction and S phase fraction in the surviving group and the deceased group offered no significant information.