Occupational and residential exposure to pesticides and the risk of neuroblastom

Neuroblastoma is a childhood neoplasm derived from poorly differentiated neural crest cells. It is the most common tumor in children under one year of age and the fourth most common neoplasm during childhood. This study examined the relationship between parental occupational and residential exposure to pesticides and the risk of neuroblastoma in off-spring using data from a case-control study of risk factors for neuroblastoma. Five hundred and thirty-eight incident cases of neuroblastoma were identified through the Pediatric Oncology Group (POG) and the Children's Cancer Group (CCG). One age-matched control was identified for each case by random digit dialing. Telephone interviews with each parent collected information on residential exposures to pesticides and a general occupational exposure history. Different exposure assessment methods were compared for classification of occupational pesticide exposure.;Pesticide use in both the home and garden were associated with a modestly increased risk of neuroblastoma [OR 1.6 (1.0--2.3) and OR 1.7 (0.9--2.1), respectively]. Stronger associations were found for garden pesticides in children diagnosed after one year of age [OR 2.2 (1.3--3.6)], suggesting that pesticides may act through a mechanism common to neuroblastoma in older children. There was no evidence for differential pesticide effects in subgroups of neuroblastoma defined by MYCN oncogene amplification or low versus advanced tumor stage.;Classification of occupational pesticides exposure varied by the method of exposure assessment used. Self-report of pesticide exposure was the most inclusive exposure group; but neither maternal nor paternal occupational exposure was associated with an increased risk of neuroblastoma in the child based on this method. Industrial hygiene review of all available occupational and exposure information was the most comprehensive method used in this study. Maternal occupational exposure by this method was not associated with an increased risk of neuroblastoma. Paternal exposure was associated with a modestly, but imprecisely, elevated risk [OR 1.5 (0.7--3.4)].;This study described how different methods of occupational exposure assessment result in different exposure classifications for individuals in population-based studies. These differences may be responsible for the inconsistent results and conclusions in studies of occupational exposures and childhood disease. A relationship between residential pesticides and the increased risk of neuroblastoma, is suggested. However, the relationship between occupational pesticides and neuroblastoma is more tenuous. Although this study critically assessed pesticide exposure from available interview data; the validity of exposure information collected through interviews must be further assessed and improved before investigations evaluating the relationship between residential and occupational pesticides and the risk of neuroblastoma, will be conclusive.