Fluoride Exposure in Drinking Water and Childhood and Adolescent Osteosarcoma in Texas *

BACKGROUND:  The incidence of osteosarcoma, a rare malignant bone tumor primarily affecting the long bones, peaks around puberty.  To date previous studies examining the relationship between fluoridated drinking water and osteosarcoma in children have been equivocal.  The purpose of this study was to examine the association between fluoride levels in drinking water and osteosarcoma among children and adolescents in Texas.  Using areas in Texas with high and low naturally-occurring fluoride, as well as areas with optimal fluoridation, we were able to examine a wide range of fluoride levels in drinking water.

METHODS:  This was a population-based case-control study, with both cases and controls obtained from the Texas Cancer Registry.  Eligible cases were Texas children and adolescents <20 years old diagnosed with osteosarcoma from 1996-2006. Controls were sampled from children and adolescents diagnosed with either brain cancer or leukemia during the same time frame, at a 4:1 control/case ratio.  Using geocoded patient addresses at time of diagnosis, we estimated each patient’s fluoride exposure level based on the fluoride level of their residence’s public water supply.  Unconditional logistic regression models were used to assess the association between osteosarcoma and fluoride level in drinking water, adjusting for several demographic risk factors.

RESULTS:  A total of 308 osteosarcoma cases, 598 leukemia controls, and 604 brain cancer controls met selection criteria and were able to be assigned a corresponding public water supply fluoride level. Fluoride level was not associated with osteosarcoma, either when analyzed in a univariable analysis or when adjusting for age, sex, race, and poverty index.  We also conducted stratified analyses by sex, and no association between public water supply fluoride level and osteosarcoma was observed either among males or females. 

CONCLUSIONS:  Our study did not find a relationship between the fluoride level in drinking water and childhood/adolescent osteosarcoma in Texas.