Screening effect of breast cancer incidence among the population of Bryansk and Orel oblasts of the Russian Federation

The study presents the estimations of screening effect for breast cancer among the population exposed as the result Chernobyl accident. The cohort selected for analysis consists of 127104 people from the most contaminated territories of Bryansk and Orel oblasts affected by the Chernobyl accident. Over the follow-up period 1996-2011, a total of 1164 breast cancer cases were identified as the result of annual compulsory health examination in Bryansk and Orel oblasts. The study showed that the spontaneous cancer incidence of breast cancer among the population of Bryansk and Orel oblasts in the period from 1991 to 2011 was statistically lower (by 8%) than the level of incidence in Russia as a whole. Statistically significant screening effect on breast cancer detection was found in the most contaminated territories of Bryansk and Orel oblasts over the period 2006 to 2011. According to the WHO (2013) model of radiation the value of excess absolute risk in the selected cohort, the proportion of radiation-caused-morbidity may reach 1.2%.