Thyroid cancer in the population living around Semipalatinsk nuclear testing site, Kazakhstan

INTRODUCTION:  thyroid gland is highly sensitive to the radiation-induced oncogenic effects. 456 nuclear explosions were conducted in the Semipalatinsk Nuclear Test Site, Kazakhstan. Regional Oncology Center centrally registered all cases of thyroid cancers for the last decades. Further analysis of collected data may permit us to find a gap in study of radiation-induced thyroid cancers. The aim was to assess the incidence, mortality and structure of thyroid cancer in population of former Semipalatinsk region, Kazakhstan in 2003–2013.

METHODS:  Information about all cancers of the thyroid gland registered in the Semipalatinsk Regional Cancer Registry during 2003–2013 was analysed.

RESULTS:   Total number of the studied cases was 338 for last decade. The analysis revealed stable rate of the thyroid cancer incidence from 2003 to 2013 (8.0 per 100,000). The same situation was in the mortality rate from all types of thyroid cancer (0.8 per 100,000). In the total histological structure dominated A-cell origin papillary carcinoma – 85.63% and follicular carcinoma – 11.83%, after C-cell origin medullary carcinoma – 1.53% and less than other B-cell origin poorly differentiated carcinoma – 1.01%. It has to be noted that all diagnosis was established and operated in early stages with the exception related only to poorly differentiated carcinoma. 

CONCLUSIONS:   The study observed a stable rate of the incidence and mortality from all types of thyroid cancer in past decade but still one of the highest in Kazakhstan. Diagnostics in early stages became possible with implementation of  screening programs in the areas around the Semipalatinsk Nuclear Test Site.