AGE-RELATED-CHANGES IN DIAGNOSES, HISTOLOGICAL FEATURES, AND SURVIVALIN CHILDREN WITH BRAIN-TUMORS - 1930-1979

IN THE CHILDHOOD Brain Tumor Consortium database, the proportions of o lder children (greater than or equal to 11 yr) with pilocytic astrocyt omas, fibrillary astrocytomas, and ependymomas significantly increased (P < 0.05) over the 50 years (1930-1979) of the study. The increased proportions of pilocytic astrocytomas occurred whether the tumors were located in the supratentorial or infratentorial compartments. The inc reases in fibrillary astrocytomas and ependymomas were found only with in the supratentorial tumor location. Some histological features found in pilocytic astrocytomas (e.g., Rosenthal fibers, granular bodies, a nd very low cell density) were more likely to be found in older childr en. Other histological features were also more likely to be found in o lder children (e.g., parenchymal calcification, intertwined fascicles, intermediate and large-size nuclei, pleomorphic, elongated, or irregu lar nuclei, prominent nucleoli, multinucleated cells, thick hyaline bl ood vessels, hemosiderin, and parenchymal and perivascular lymphocytes ). The probability of 5-year survival for young children with supraten torial ependymomas remained at similar to 0.4 in contrast to that for young children with infratentorial ependymomas, for whom it improved, but without significant linear trend. The probability of 5-year surviv al for both younger and older children with primitive neuroectodermal tumors (medulloblastomas) improved, but without significant linear tre nd. The changes in the proportions of childhood brain tumors and histo logical features occurred without similar changes in the proportions o f older and younger children in the cities involved between 1930 and 1 979. These changes were so distinctive as to raise the possibility of significant shifts in environmental exposures in younger and older chi ldren over the 50 years of this study.