26 Thyroid Cancer Cases Confirmed in Fukushima Children: Preliminary Results of FY2011-2013 Thyroid Ultrasound Examination
Thirteenth Prefectural Oversight Committee convened on November 12, 2013, releasing the results of the latest thyroid examination as part of the prefectural health management survey.
Total number of children examined as of September 30, 2013: 289,960
Total number of children whose initial examination results are confirmed: 225,537
(up to the August 23rd, 2013 examination)
Assessment A1 121,525 (no nodules or cysts found)
Assessment A2 102,453 (nodules 5.0 mm or smaller or cysts 20.0 mm or smaller)
Assessment B 1,558 (nodules 5.1 mm or larger or cysts 20.1 mm or larger)
Assessment C 1 (requiring immediate secondary examination)
Secondary examination includes more detailed thyroid ultrasound, blood and urine tests, and fine-needle aspiration biopsy if warranted.
1,559 are eligible for secondary examination
1,148 have actually undergone secondary examination
897 finished the secondary examination
During the press conference following the committee meeting, no information was given, as to the details of individual cancer cases, such as the presence of lymph node metastasis or the type of surgery done.
Shinichi Suzuki maintains that this thyroid examination was originally initiated to assess the baseline thyroid condition of Fukushima children, as there is no such epidemiological data available in Japan, with an understanding that it was not possible to obtain pre-exposure data. It is being conducted on an assumption that the effect of radiation exposure would not be obvious for at least four years after exposure, as was seen after the Chernobyl accident.
If these cancer cases were indeed screening effects, similar malignancy would have to be expected in other parts of Japan. As for the thyroid survey conducted by the Ministry of Environment in Aomori, Yamanashi and Nagasaki Prefectures, widely recognized as a comparison study, no cancer data is available from the cases of thyroid ultrasound abnormalities detected. Also it is not age- and gender-matched, and there is a question about the possibly uneven quality of ultrasound examination itself between the two studies. The MOE spokesperson indicated that abnormal cases are undergoing further examination, and more data might become available for comparison.