Ohtsuru A, et al. - In this cohort study, 324,301 kids and young adults were analyzed to estimate the number of identified thyroid cancers by age group within 5 years of the Fukushima Daiichi nuclear power station accident, and to compare the basic clinical features and demographic patterns in first (fiscal years 2011-2013) and second round (fiscal years 2014-2015) reviews. The distribution pattern of the incidence rate increased by age group at the time of screening in the second round with older age. They observed the following incidence rates: 29 cases per 100,000 person-years for candidates of age 15 to 17 years, 48 cases per 100,000 person-years for those aged 18 to 20 years, and 64 cases per 100,000 person-years for those aged 21 to 22 years.