Research on the relationship between iodine exposure and thyroid cancer risk is limited and the findings are inconclusive.
Objectives: Given this molecular data on iodine we decided to evaluate the changes of incidence and histology of thyroid cancer in the North-Eastern region of Romania (Moldavia) after the government decision from 2004 that introduced the universal iodination of alimentary salt. After this decision values of urinary iodine increased from 50 microg/L (2001-2002) to 117 microg/L (2006 -2008).
Material and methods: We compared the incidence and the histology of thyroid cancer in residents living in an area known as a mild endemic goiter region (Moldavia-Romania) between 2001-2004 with the incidence and the histology of thyroid cancer between 2005-2008 in the same region after the introduction of universal iodization of alimentary salt.
Results: The number of papillary cancers increased from 125 cases (2001-2004) to 276 cases (2005-2008). The number of follicular cancer decreased from 52 cases (2001-2004) to 27 cases (2005-2008). The ratio between papillary and follicular cancers increased from 4.80 / 1 (2001-2004) at 10.61 / 1 (2005-2008). The number of medullar thyroid carcinoma increased from six cases (2001-2004) to 24 cases (2005-2008). Thyroid anaplastic carcinomas number increased from 7 cases (2001-2004) to 12 cases (2005-2008). The total number of thyroid cancer has increased dramatically after the introduction of universal iodination of alimentary salt with 178% compared to 2001-2004 (from 190 cases in 2001-2004 to 339 cases in 2005-2008), despite the fact that the number thyroidectomies decreased from 1734 (2001-2004) to 1449 (2005-2008).
Conclusion: After the introduction the universal iodination of alimentary salt starting from 2004 the total number of thyroid cancers increased comparative with the period before universal iodination of alimentary salt.