DID CHERNOBYL ACCIDENT CONTRIBUTE TO THE RISE OF THYROID CANCER IN TURKEY?

Context. Radioactivity has been known to be a causative factor for thyroid cancer. Objective. To answer whether the Chernobyl nuclear accident had any harmful effect on the rate of thyroid cancers after a wait-and-see period. Background. The Chernobyl accident in 1986 was chosen as a milestone because of its close proximity to the geographical area studied. Design. The time periods chosen were: I. 1990-1996 (latent period), II. 1997-2003 (sensitive period), III. 2004-2015 (control period). Subject and Methods. A retrospective study was conducted in a teaching and reference state hospital. The statistical analysis of the data of 4251 patients was made by chi-square and Fisher exact tests. Results. A total of 4251 patients were operated on because of thyroid diseases between 1990-2015. The number of patients in regard to the three time periods were 817, 1141 and 2293, respectively. Statistically significant rise of thyroid cancer and significant geographic vulnerability among different parts of the country were detected between the first two periods, but not between the second and third. The rising rates of malignancy were 1.71% (14/817), 6.83% (78/1141) and 8.59%(197/2293). The mean ages of malignant cases were 51.07 years, 46.2 years and 41.8 years although the mean ages of benign cases were 47.91,60.2, and 61.3 years according to groups, respectively. Conclusion. The Chernobyl nuclear accident seemed to have harmful effect on the rate of thyroid cancer or at least contributed to its increase.