In Fukushima Prefecture, the prefectural government has been following up the children under 19 years at the time of nuclear power plant accidentfor the possibility of thyroid cancer. That is, the researchers at Fukushima Med University have done ultrasonogram for thyroid gland for them. They have examined 290000 out of 360000 children satisfying the requirements for the past 3 years. Among those undergone aspiration biopsy as the suspicious cases, 90 children were diagnosed as thyroid cancer or its suspect. Fifty one have undergone resection of the tumor and 50 of them were given definite diagnosis of thyroid cancer. The researcher told some of them had had some symptoms of remote metastasis or local invsion of the tumor.
This is what a recent news has reported to us. I don't know how to evaluate this large scale study and its result. Since most of the thyroid cancer have been told to be "occult", it was shocking to me certain percentage of the children with thyroid tumor had already got some symptoms. it won't be occult any longer. In the prefectural committee, there still seemed to be a discussion about comparing those with normal age matched control in different areas. Epidemiological data regarding childhood thyroid cancer is very few espcecially from such thorough check up among the population in certain area. Without such normal control, this result won't be exactly appreciated at all. I thought they had already taken such normal control data in two different areas. What did they do with that data? Is there anything wrong in publishing the comparison? The raw data regarding those thyroid cancer proven cases should be published. I am afraid they would keep the data unpublished. It would cause unnecessary suspicion regarding this study.
In Chernobyl, thyroid cancer has occured among many children in 4 or 5 years after the accident. The newer and more sensitive device of ultrasonogram might have detected them earlier in Fukushima. We should keep our eyes on what goes on there.