An Ethical Issue After the Nuclear Accident in Fukushima: Young People’S Perspectives of Thyroid Cancer Screening and its Harms

Abstract

Background Overdiagnosis of thyroid cancer has become a major global medical issue. Ultrasound-based thyroid cancer screening has promoted overdiagnosis, and recently international recommendations indicate that such screening should not be conducted, even after a nuclear accident. The Fukushima thyroid cancer screening program was initiated in 2011 as a health policy after the nuclear accident, although the risk for radiation-induced thyroid cancer was unlikely given the low radiation levels. However, the thyroid cancer screening program has continued at 2-year intervals with a relatively high participation rate and is now in its fifth round. Therefore, it is crucial to clarify whether those targeted for screening understand the disadvantages of screening and identify factors that influenced their decision to participate. Methods We conducted an anonymous mail-based questionnaire that included young people from Fukushima (subjects) and a neighboring prefecture that was not targeted for screening (non-subjects). We asked them about the significance of the thyroid cancer screening in Fukushima, the reasons for taking or not taking a screening, their perception of the harms of screening, and their opinions on thyroid examination at school. Then we compared the results of the questionnaire between subjects and non-subjects and examinees (who accepted screening) and non-examinees (who declined screening). Results Only 16.5% of respondents were aware of the harms associated with thyroid cancer screening, with most perceiving that the benefits outweighed the harms. Comparison of subjects’ and non-subjects’ responses showed there were no significant differences between subjects and non-subjects. In addition, among subjects, there were no differences of responses between examinees and non-examinees. The most common reason for participation in screening was that the screening was conducted in schools and perceived as obligatory. Conclusions These results highlighted a serious ethical issue in that school-based screening leads to making young people think that it is mandatory screening in an opt-out and default setting manner, with a lack of knowledge about the disadvantages of screening. Based on the autonomy of the subjects and the ethical principle of the post-disaster, surveys after a nuclear disaster should be conducted in an opt-in style without an opt-out style such as school-based screening.