CHILDHOOD BRAIN-TUMORS AND EXPOSURE TO TOBACCO-SMOKE

Brain tumors are the second most common cancer in children after leuke mia, yet the etiology of childhood brain tumors remains unknown. Tobac co smoke contains several dozen compounds that are known to be carcino gens. Among these are N-nitroso compound precursors, principally tobac co-specific nitrosamines. Although smoking has not been identified as a significant risk factor for the development of brain tumors in adult s, fetuses and infants have incompletely formed blood-brain barriers t hat may allow the passage of carcinogenic tobacco metabolites into the central nervous system and initiate the formation of neural tumors. I n this review, we present data from case-control and cohort studies pu blished between 1971 and 1995 that examined the relationship between p arental smoking during pregnancy and childhood brain tumors (CBTs), Th e majority of these studies found little association between CBTs and maternal smoking before or during pregnancy or between CBTs and matern al exposure to passive smoke during pregnancy.