On March 30, 2017, it was broadcast on both Fukushima and nationwide NHK channels that Fukushima Prefecture has not reported thyroid cancer diagnosed in a boy who was age 4 at the time of the 2011 Fukushima Daiichi nuclear power plant accident. The case came to light when the 311 Fund for Children with Thyroid Cancer revealed he was one of six applicants that received aid in February 2017. (Video of the statement in Japanese on this website. See the section "Thyroid cancer cases outside Fukushima Prefecture" on this post for more information on the 311 Fund for Children with Thyroid Cancer).
The TUE, commissioned by Fukushima Prefecture to Fukushima Medical University, is conducted through the fund provided by the central government. The primary examination is screening by ultrasound. Those meeting certain criteria go on to the confirmatory examination where the majority end up being placed back on the regular screening schedule every 2-5 years. However, some are shifted to regular medical care covered by the national health insurance, either for follow-up with more frequent ultrasound or for further testing and/or treatments such as cytology and surgery. This shift apparently puts these cases beyond the scope of screening as per Fukushima Medical University, which has consistently refused to provide detailed information on such cases, citing privacy concerns.
The child was diagnosed with thyroid cancer while under follow-up after going through the confirmatory examination during the second round of the Thyroid Ultrasound Examination (TUE) conducted in FY2014-2015. After the fine-needle aspiration cytology in 2015 showed suspected cancer, he underwent thyroidectomy in the first half of 2016. The fact his case—the youngest reported so far at age 4—never appeared in the officially reported results suggests cancer cases diagnosed during follow-up are not reported, which was admitted by Fukushima Medical University. There are over 2500 individuals followed up from the first to third rounds so far (see table in this Japanese article).
Below is an unofficial translation of the NHK nationwide coverage posted here and archived here.
Thyroid Examination After the Nuclear Power Plant Accident: Cancer Diagnosed in a Four-Year-Old Boy Goes Unreported
March 30, 8:24pm
Since the Fukushima Daichi nuclear power plant (FDNPP) accident, Fukushima Prefecture has been conducting the Thyroid Ultrasound Examination in children who were ages 18 or younger at the time of the accident, reporting the results to an expert committee evaluating health effects of the accident, the Oversight Committee for the Fukushima Health Management Survey. However, NHK’s investigation revealed thyroid cancer diagnosed in a child who was 4 years old at the time of the accident time has not been reported to the Committee.
After the FDNPP accident, Fukushima Prefecture commissioned Fukushima Medical University to conduct the Thyroid Ultrasound Examination to detect lumps in the thyroid gland of about 380,000 children who were age 18 or younger at the accident time. This age group is known to be sensitive to the effect of radioactive iodine.
Fukushima Prefecture reports the results to the Oversight Committee evaluating health effects of the accident. By the end of the last year, it was reported that 185 individuals in the age range 5-18 at the time of the accident had been diagnosed with cancer or suspected cancer.
However, NHK’s investigation revealed that Fukushima Medical University was aware of but failed to report to the Oversight Committee about the youngest patient to date—a child aged 4 at the time of the accident—who was diagnosed with thyroid cancer after the Thyroid Ultrasound Examination and had the thyroid gland removed.
The Thyroid Ultrasound Examination consists of two steps: the primary and the confirmatory examinations. Fukushima Prefecture and Fukushima Medical University explain, “We report cases in patients who were diagnosed with cancer or suspected cancer during the confirmatory examination. We do not report thyroid cancer cases diagnosed either in patients assigned to “follow-up” as a result of the confirmatory examination or in patients diagnosed after transferring to other medical facilities, due to difficulties in comprehensive recording of such cases.”
When an Oversight Committee member questioned two years ago about a potential issue in reporting cancer cases diagnosed during follow-up, Fukushima Medical University explained that patients diagnosed with thyroid cancer after the confirmatory examination would be “reported separately.” However, no such reporting has occurred.
An Oversight Committee member and former vice president of Fukushima University, Special Professor Shuji Shimizu points out, “The mission here is to release and analyze accurate information. So that no doubt arises that anything might be hidden, thyroid cancer cases should be disclosed as facts no matter what the circumstances of diagnosis may be.”
What is thyroid cancer?
Thyroid gland is a small, butterfly-shaped organ, located below the Adam’s apple and weighing about 10 to 20 grams. Its function is to secrete hormones involved with growth promotion.
After the FDNPP accident, “thyroid cancer” became a concern as it can be caused by the thyroid gland absorbing “radioactive iodine” which is one of the radioactive materials released due to the accident.
In particular, children in a growth process are considered to be sensitive to the effect of radioactive iodine, because the repair of chromosomal damages cannot keep up with active and repeated cell divisions occurring in the body.
After the Chernobyl nuclear power plant accident in former Soviet Union, residents in surrounding areas took in “radioactive iodine” mostly through consumption of milk and dairy products. The United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) reported that about 6000 residents developed thyroid cancer and 15 died by 2006.
All children who were 18 or younger targeted by the Thyroid Ultrasound Examination
After the FDNPP accident, Fukushima Prefecture commissioned Fukushima Medical University to conduct the Thyroid Ultrasound Examination in all 380,000 children who were age 18 or younger and lived in the prefecture at the time of the accident.
Using the 78 billion yen ($700 million) fund contributed by the central government, the Thyroid Ultrasound Examination is conducted once every two years up to age 20 and every five years after age 20.
The Thyroid Ultrasound Examination consists of two steps. The primary examination, often conducted in school settings, involves placing the ultrasound probe on the neck to detect any lumps in the thyroid gland. The results are given as four-level assessments.
Those who are assessed to have lumps above a certain size undergo the confirmatory examination for more detailed testing.
The confirmatory examination consists of more detailed ultrasound examination, blood tests, and fine-needle aspiration cytology (FNAC) as needed. In FNAC, a needle is inserted into the lump in order to distinguish between benign and malignant tumors.
The first round of the examination commenced in October 2011, and the second round in 2014. Currently the third round is underway.
The latest data reported last month shows a total of 185 individuals—116 in the first round and 69 in the second round—were diagnosed with “cancer” or “suspected cancer” as of December 31, 2016.
Age at accident ranges from 5 to 18, with the youngest being a 5-year-old boy reported in June 2016.
An Oversight Committee member says “The level of confidence for the Thyroid Ultrasound Examination might fall”
Regarding the revelation of thyroid cancer patients not reported to the Oversight Committee, an expert points out that the level of confidence for the Thyroid Ultrasound Examination might suffer.
The Thyroid Ultrasound Examination results are regularly reported to the Oversight Committee consisting of 15 experts including cancer specialists and university professors. The Committee conducts scientific evaluation regarding the relationship between thyroid cancer and the nuclear accident.
In 2015 and 2016, the Oversight Committee released mid-term reports on thyroid cancer diagnosed in Fukushima Prefecture after the FDNPP accident, stating, “Overall, they are unlikely to be due to the effects of radiation.”
Reasons mentioned in the report include the following: radiation doses were much lower compared to those after the Chernobyl accident; thyroid cancer cases were not seen in ages 5 or younger as commonly seen in Chernobyl; and Fukushima cases were detected in a short time span of 1-4 years after the Fukushima accident, while the Chernobyl cases were discovered beginning 5 years after the Chernobyl accident.
Later, it was reported to the Oversight Committee meeting in June 2016 that thyroid cancer had been diagnosed in a 5-year-old boy for the first time. Nevertheless, the Committee’s stance, “unlikely due to the effect of radiation,” has not changed.
An Oversight Committee member and former vice president of Fukushima University, Special Professor Shuji Shimizu emphasized that the news of thyroid cancer in the youngest patient to date—a child who was four at the time of the accident—should be calmly received. He stated, “This case is neither surprising nor strange because the risk for cancer increases with age.” He further commented about the unreported cancer cases, “The mission here is to release and analyze accurate information. Any thyroid cancer cases should be disclosed as facts no matter what the circumstances of diagnosis may be, with special precaution to ensure protection of personal information. Otherwise doubts will arise that something might be hidden, reducing the level of confidence for the Thyroid Ultrasound Examination as a whole.”
Fukushima Prefecture “will consider the release of information based on discussion at the Oversight Committee”
Regarding unpublicized thyroid cancer patients, Fukushima Medical University states the department in charge of the Thyroid Ultrasound Examination does not have information on thyroid cancer cases diagnosed during follow-up or as a result of medical care and testing at other medical facilities unrelated to Fukushima’s Thyroid Ultrasound Examination.
Fukushima Medical University further explains that the “regional cancer registry” system mandating submission of cancer patient data by medical facilities is collecting and releasing more precise information.
A physician who was in charge of the Thyroid Ultrasound Examination at Fukushima Medical University stated during NHK’s interview that “Most of the patients diagnosed with thyroid cancer during follow-up after the confirmatory examination are receiving medical treatments at Fukushima Medical University, but we do not have exhaustive information covering all cases. Release of such information should be conducted carefully in order to avoid arbitrariness. We are doing the best for the sake of the patients without a doubt.” Regarding the reporting system that excludes patients diagnosed with cancer during follow-up after the Thyroid Ultrasound Examination, he further stated, “How to deal with that is a real problem which has remained an issue since I was in charge of the Thyroid Ultrasound Examination.”
Fukushima prefectural government's Division of the Fukushima Health Management Survey that commissions the Thyroid Ultrasound Examination to Fukushima Medical University states, “We are aware that thyroid cancer cases diagnosed during follow-up after the Thyroid Ultrasound Examination are not included in the reported results. We understand such cases potentially exist, but we are unaware of individual cases. We will consider releasing such information in the future based on discussion at the Oversight Committee.”