Osteosarcoma in Republic of Ireland 
and Northern Ireland

Dr M Owens1, Dr B O’Herlihy1
Department of Public Health, HSE East, Dr Steevens’ Hospital, Dublin 8
June 29 2009

Introduction

Osteosarcoma is a rare bone cancer. Worldwide the approximate annual incidence of osteosarcoma is 2-3 per million in the general population. (1) 

A paper by Bassin et al has sparked some new debate regarding their observed association between exposure to fluoride in drinking water and the incidence (new cases) of osteosarcoma in young males.(2) No apparent association was observed in females. This exploratory analysis had limitations and the findings were not replicated in preliminary analysis of a second set of cases. 

The National Research Council Committee on Fluoride in Drinking Water has considered all available evidence on fluoride and osteosarcoma, including prepublication data from the analysis by Bassin above and has concluded that that the overall evidence on osteosarcoma to be tentative and mixed, and no recommendations were made related to this health concern for revising current allowable fluoride levels in drinking water. (3)

The Centre for Disease Control (CDC) has issued a statement on water fluoridation and osteosarcoma which sets out the current scientific evidence and its continued support for community water fluoridation as a safe and effective public health measure to prevent and control tooth decay and to improve overall health. (4)

Cancer Registry Data

In 2006 a report on cancer registry data was prepared for the Irish Expert Body on Fluorides and Health.(5) This evaluated the cancer data for the period 1994 to 2000 and concluded that there was no indication of an increased risk of osteosarcoma associated with fluoridated drinking water.

Cancer registry data from the National Cancer Registry in Ireland (NCRI) and the Northern Ireland Cancer Registry (NICR) have been compared and presented below and demonstrate that there is no evidence that between water fluoridation is associated with development of  osteosarcoma in Ireland where drinking water is fluoridated.

Results
Analysis has been undertaken to provide comment on the cancer data for the years 2001 to 2006. 

This analysis shows a rate of osteosarcoma in the ROI of 0.25 /100,000 for the period 1994 to 2007. Data for Northern Ireland covered the years 1994 to 2006 and showed an overall rate of 0.21 /100,000.

Figure 1 below shows the number of cases in each jurisdiction. As the population in the ROI is higher than that in Northern Ireland the number of cases of osteosarcoma in ROI are obviously higher as can be seen in Figure 1 below. 
The incidence rates, age standardised to the European population, for both jurisdictions are shown in Figure 2. This is a more meaningful and accurate method of presenting data on any disease and particularly in the case of a rare cancer where the number of cases is relatively small.  

Figure 1 Cases of osteosarcoma

Figure 2 Age standardised incidence rates of osteosarcoma

In summary, it can be seen from the above figures that the incidence of osteosarcoma is comparable in both  jurisdictions and in fact in some years the rate in Northern Ireland was higher that in the ROI.

Acknowledgements
National   Cancer Registry Ireland,   
Northern Ireland Cancer Registry  

References 

1.	Bielack SS, Bernstein ML. Cancer in children: clinical management    5th edition, ed.: Oxford University Press; 2005.
2.	Bassin EB, Wypij D, Davis RB, Mittleman MA. Age-specific fluoride exposure in drinking water and osteosarcoma (United States). . Cancer Causes and Control. 2006;17:421-8.
3.	Water. NRCCoFiD. Fluoride in drinking water: A scientific review of EPA’s standards
Washington, D.C:; 2006 Contract No.: Document Number|.
4.	CDC. CDC Statement on Water Fluoridation and Osteosarcoma. Journal [serial on the Internet]. 2009 
5.	McCarthy D, O'Herlihy B, Staines A. Water Fluoridation and Osteosarcoma. 2006.