Thyroid cancer has increased 12-fold in women since Chernobyl

By Roger Dobson, BMJ.com, 12 June 2004

Rates of thyroid cancer among women in Belarus have increased up to 12-fold since the explosion at the Chernobyl nuclear power plant, near Kiev, Ukraine, in April 1986.

Among young women aged under 14 in higher risk areas of the republic the rates have increased almost 30-fold since the disaster, new research has shown.

“This study documents dramatic increases in the incidence of thyroid cancer among both higher exposure and lower exposure areas within the republic of Belarus and among all age groups studied,” says an “advance access” report of the study published online on 27 May in the International Journal of Epidemiology

It adds: “The magnitude of increases observed is remarkable given the relatively limited time interval since Chernobyl and argues for continued surveillance in Belarus as well as other affected areas.”

The explosion at Chernobyl resulted in the release of substantial amounts of radioactive materials over western regions of what was then the Soviet Union, including radioisotopes of iodine, caesium, strontium, and plutonium.

The most significant contamination was in Belarus and Ukraine, as well as the western region of the Russian Federation.

The report says that although previous studies of the incidence of thyroid cancer in Belarus have shown an increase since the Chernobyl explosion, the size of the increase is not well quantified.

The authors, from the Roswell Park Cancer Institute, New York, and the Institute of Oncology, Minsk, used data from the Belarus national cancer registry and trends in average annual incidence of thyroid cancer.

The data show big increases since 1986. Between 1980 and 1986, for example, there were 0.15 cases per 100 000 diagnosed in girls aged under 14 in high risk areas. By the period 1997-2001, the rate had gone up to 43.84. Among males of the same age, the rate went up from 0.08 to 18.81.