CASE-CONTROL STUDY OF NEUROBLASTOMA IN WEST-GERMANY AFTER THE CHERNOBYL ACCIDENT

Background To explore possible causes of a 1988 incidence peak of infa nt neuroblastoma in west German regions which were contaminated with m ore than 6000 Bq/m(2) Cs137 from the Chernobyl accident. The primary w orking hypothesis was that parents of the diseased children had been c ontaminated by an excessive intake of locally produced food, especiall y mushrooms or deer. Design Case control study with 1:2 (cases:control s) matching. Data were collected from the children's parents by questi onnaires and telephone interviews. Setting Nation-wide study (former F RG) based on the German Childhood Cancer Registry. Subjects Cases born in 1988 and reported with a neuroblastoma to the registry until March 1992. Population-based healthy controls, matched for age, sex and res idence at time of diagnosis. Results The working hypothesis could not be confirmed by the study, because the parents of cases tended to eat less locally grown food than the parents of controls (RR = 0.63, 95% C I: 0.20-1.97). Possible influence factors which previously have been d escribed to be associated with neuroblastoma incidence could not be co nfirmed by the study. Parental exposure to herbicides and pesticides w as associated with the occurance of neuroblastoma (RR = 4.2. 95% CI: 1 .4-12.9). Neuroblastoma stage distribution in the contaminated regions was shifted towards lower stages as compared to the less contaminated regions and previous age cohorts. Conclusions The study does not show additional evidence that the observed increase in neuroblastoma incid ence might have been caused by exposure to fallout from the Chernobyl accident, The observed shift towards lower clinical stages may rather indicate increased diagnostic awareness. The association between neuro blastoma and parental exposure with herbicides and pesticides resulted from an extensive exploratory data analysis and needs to be confirmed in further studies.