Fukushima Thyroid Examination September 2016: 135 Thyroid Cancer Cases Confirmed (101 in the First Round and 34 in the Second Round)


135 Thyroid cancer cases confirmed in Fukushima as of June 30, 2016--101 in the first round and 34 in the second round (Total of 174 cases including suspected cancer cases--115 in the first round and 59 in the second round).


The 24th Prefectural Oversight Committee for Fukushima Health Management Survey convened in Fukushima City, Fukushima Prefecture, on Wednesday, September 14, 2016. 

Among other information, the Oversight Committee released the latest results (as of June 30, 2016) of the second round screening, which was conducted over a two-year period from April 2014 to March 2016. The second round screening is still ongoing in terms of the confirmatory examination, so the results are not complete.

An official English translation of the results is available here. The narrative below contains some information gathered from the live webcast of the Oversight Committee meeting and the subsequent press conference. 

Overview

As of June 30, 2016, there are 2 more cases with malignancy or suspicion of malignancy from the second round, for a total of 174 (175 including the single case of post-surgically confirmed benign nodule). The number of surgically confirmed cancer cases, excluding the aforementioned case of benign nodule, now totals 135 (101 from the first round and 34 from the second round), and the remaining 39 (14 from the first round and 25 from the second round) await surgical confirmation. 

Although the final results of the second round screening were widely anticipated at this Oversight Committee meeting, it turned out only two-thirds of those who were eligible for the confirmatory examination actually participated as of June 30, 2016. (Many of them might have undergone the confirmatory examination during the summer break, typically from late July through August).

Since the last results were released, only 4 additional cases from the second round have been operated on. Post-surgical pathological examination of the resected thyroid gland tissue confirmed 3 as papillary thyroid cancer and 1 as "other thyroid cancer" according to the classification in the seventh revision of Japan's unique thyroid cancer diagnostic guidelines released in November 2015.


Full-Scale Screening
To be conducted every 2 years until age 20 and every 5 years after age 20, the Full-Scale screening began with the second round screening in April 2014, including those who were born in the first year after the accident. There are 381,281 eligible individuals born between April 2, 1992 and April 1, 2012. As of June 30, 2016, 270,378 actually participated in the primary examination at the participation rate of 70.9% (lower than 81.7% at the first round screening). 270,327 have received confirmed results of the primary examination, and 2,217 (increased by 156 since the last Oversight Committee meeting) turned out to be eligible for the confirmatory examination. 

The confirmatory examination is still only about two-thirds complete. Of 1,476 who actually underwent the confirmatory examination, 1,379 received confirmed results including 176 that underwent fine-needle aspiration cytology (FNAC). FNAC revealed 59 cases suspicious for cancer. Confirmation of thyroid cancer requires pathological examination of the resected thyroid tissue obtained during surgery. As of June 30, 2016, 34 underwent surgery and 33 were confirmed to have papillary thyroid cancer. One remaining case was confirmed to have "other thyroid cancer" according to the classification in the seventh revision of Japan's unique thyroid cancer diagnostic guidelines. A specific diagnosis was not revealed, but Akira Ohtsuru, in charge of the thyroid screening, confirmed that it was a differentiated thyroid cancer that is not known to be related to radiation exposure.

Newly diagnosed cases in the second round
In the second round, 2 cases were newly diagnosed by FNAC to be malignant or suspicious of malignancy. They were 2 females (age at exposure: 12 and 14). Their places of residence at exposure were Iwaki City and Tadami Town, both of which are FY 2015 target municipalities.

In relation to the still ongoing confirmatory examination, special attention should be paid to the participation rate in Iwaki City. Of 45,228 Iwaki City residents who participated in the second round screening, 376 were eligible for the confirmatory examination. Only 172 have actually participated in the confirmatory examination as of June 30, 2016, and 134 of them have confirmed results. Thus, more confirmatory examination results are expected from Iwaki City, the largest of the FY2015 target municipalities. 

Prior diagnostic status of the cases newly diagnosed in the second round
Of 59 total cases with malignancy or suspicion of malignancy in the second round, 28 were A1, 26 were A2, and 5 were B in the first round.  

28 cases that were A1 in the first round screened suspicious for malignancy in the second round. This would appear to be a new onset after the first round since A1 cases by definition have no ultrasound findings of cysts or nodules.

In 26 cases that were A2 in the first round, 7 were nodules and 19 were cysts. (Two cases with malignancy or suspicion of malignancy reported this time are deduced to be A2 cysts in the first round). Thus the majority of the second round cases appeared to have developed thyroid cancer in 2 to 3 years since the first round. However, Ohtsuru explained this time that at certain ages in children, existing ultrasound lesions may not be visible until a few years later, suggesting there might have been invisible lesions in the first round which only became visible as the child aged.


First Round Screening (October 2011 - April 2015)
(This is the final results as of March 31, 2016. It is unchanged from the previous report).

Total number targeted: 367,672
Number of participants in primary examination: 300,476
Number with confirmed results: 300,476
  • A1   154,607 (51.5%) (no nodules or cysts found)
  • A2   143,575 (47.8%) (nodules ≦ 5.0 mm or cysts ≦ 20.0 mm)
  • B        2,293   (0.8%) (nodules ≧ 5.1 mm or cysts ≧ 20.1 mm)
  • C               1   (0.0%) (requiring immediate secondary examination)
(Note: Cysts with solid components are treated as nodules).

Number eligible for confirmatory (secondary) examination: 2,294
Number of participants in confirmatory (secondary) examination: 2,128
Number with confirmed results : 2,086
Number of fine-needle aspiration cytology (FNAC): 545
Number suspicious or confirmed of malignancy: 116 (including one case of benign nodules)

Number with confirmed tissue diagnosis after surgery: 102
  • 1 benign nodule
  • 100 papillary thyroid cancer
  • 1 poorly differentiated cancer


Second Round Screening (April 2014 - March 2016) (see report here)

Total number targeted: 381,281
Number of participants in primary examination: 270,378
Number with confirmed results: 270,327
  • A1   108,619 (40.2%) (no nodules or cysts found)
  • A2   159,491 (59.0%) (nodules ≦ 5.0 mm or cysts ≦ 20.0 mm)
  • B        2,217   (0.8%) (nodules ≧ 5.1 mm or cysts ≧ 20.1 mm)
  • C              0   (0.0%) (requiring immediate secondary examination)
(Note: Cysts with solid components are treated as nodules).

Number eligible for confirmatory (secondary) examination: 2,217
Number of participants in confirmatory examination: 1,476
Number with confirmed results: 1,379
Number of FNAB: 176
Number of cases with malignancy or suspicion of malignancy: 59
Number with confirmed tissue diagnosis after surgery: 34

  • 33 papillary thyroid cancer
  • 1 "other thyroid cancer"

Third Round Screening (May 2016 - March 2018) (see report here)

Total number targeted: 381,172
Number of participants in primary examination: 17,481
Number with confirmed results: 0




Unofficial translation of selected tables

Second Round Screening


Table 1. Primary examination coverage as of June 30, 2016

Table 2. Number and proportion of children with nodules/cysts as of June 30, 2016

Table 3. Participation rates by age group as of June 30, 2016

Table 4. Comparison with the Initial (Preliminary Baseline) Screening as of June 30, 2016

Note 1: Top line refers to the results of the Preliminary Baseline Screening for confirmed results of the Full-Scale Screening.

            It is not the breakdown of the total Preliminary Baseline Screening results, 300,476.

Note 2: Top line refers to the breakdown of the Full-Scale Screening results in a given category of the Preliminary Baseline Screening results. 

            Bottom line shows the proportion in %.

Table 5. Confirmatory testing coverage and results as of June 30, 2016

Table 6. Cytology results (including information from Appendix 6: Number of surgeries among cases with malignancy or suspicion of malignancy) as of June 30, 2016

Figure 3. Distribution of cases with malignancy or suspicion of malignancy by age (as of March 11, 2011) and sex (females in white and males in gray)


Figure 5.  Estimated external effective doses of those who submitted basic survey questionnaire as of June 30, 2016 (females in white and males in blue) 


Third Round Screening

Table 1. Primary examination coverage as of June 30, 2016


【Thyroid Cancer in Fukushima】Fukushima Thyroid Examination Under Dual Review


Below is unofficial translation of two Fukushima Minyu articles regarding the review of the thyroid examination, published on August 8, 2016 (archived here) and July 4, 2016 (archived here). The August article is based on an interview of Hokuto Hoshi, Chair of Oversight Committee for the Fukushima Health Management Survey. It might be tied to this postThe July article covers the launch of an independent exploratory committee by Fukushima Pediatric Association. 

Interestingly, a telephone inquiry by a concerned citizen revealed the Division of the Fukushima Health Management Survey at the Fukushima Prefectural Office was unaware of the content of the August article before its publication in newspaper. They declined to comment on the issue for the time being while contacting Oversight Committee Chair Hoshi to confirm facts and discuss the issue internally.

On September 26-27, 2016, the 5th International Expert Symposium “Chernobyl+30, Fukushima+5: Lessons and Solutions for Fukushima’s Thyroid Question” will be held in Fukushima, organized by Nippon Foundation and co-organized by Fukushima Medical University, Nagasaki University and Sasakawa Memorial Health Foundation. Judging from the symposium theme, there seems to be a rush to bring closure to the thyroid cancer issue even before the final results of the second round screening are released. A glance at the program is quite revealing.

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Oversight Committee for the Fukushima Health Management Survey Plan to Review the Thyroid Examination: Reduction in Target Population Considered

August 8, 2016 

Oversight Committee for the Fukushima Health Management Survey, engaged in discussion on the status of the survey to examine the health effects due to the nuclear accident, will begin discussions as early as September to consider reduction in target population as well as review of the screening procedure.

The thyroid examination that targets all residents who were age 18 or younger at the time of the accident will face a big turning point, as revealed by the Oversight Committee Chair Hokuto Hoshi in the interview with Fukushima Minyu as of August 7th.

The thyroid examination targets about 380,000 residents. Thyroid cancer cases detected by the examination are considered “unlikely to be the effect of radiation exposure at this time” by the Oversight Committee.

What lies behind starting the discussion to consider review of the examination is the concern about detection of “latent cancer” cases, which exist at a constant rate regardless of radiation exposure, by screening with high sensitivity. 

Thyroid cancer is curable in many cases, and the across-the-board cancer screening is unlikely to give rise to the merit of “reduced mortality.” Thus thyroid cancer screening is not globally recommended. This has led medical providers to voice concerns that “participation in the examination alone can be detrimental to the participants.”

Under the circumstance, the Oversight Committee is expected to begin discussions on issues such as: 1) Whether residents older than age 18 should be included in the target population in the future; and 2) Whether to change the method of mass screening currently conducted in school settings which has been pointed out to interfere with the participant’s wish not to participate.

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“Thyroid Examination” Should Be Reviewed: Fukushima Pediatric Association to Establish an Independent Committee

July 4, 2016

Fukushima Pediatric Association (president: Kazuhiro Ohga) adopted a general assembly statement incorporating the establishment of its own exploratory committee to consider the status of the thyroid examination on July 3, 2016 at the general meeting held in Kooriyama City. The thyroid examination, part of the Fukushima Health Management Survey that investigates health effects of the Tokyo Electric Fukushima Daiichi nuclear power plant accident, is conducted by the prefecture targeting residents who were age 18 or younger at the time of the accident. The association deems necessary to review the thyroid examination, taking a fresh look at part of it. This is the first time the association expresses the need to review the examination.

Five years have passed since the nuclear accident, a question was raised about the status of the thyroid examination mainly by pediatricians performing medical examinations on residents who are targeted for the thyroid examination.

According to the Fukushima Pediatric Association, there are 172 individuals (as of the end of March 2016) who have been diagnosed with thyroid cancer or “suspicion of cancer.” Thyroid cancer is curable in many cases, and the screening is unlikely to give rise to the merit of “reduced mortality,” while there is a mental detriment when diagnosed with cancer. Thus thyroid cancer screening is not globally recommended.

The general assembly statement referred to health worries experienced by children participating in the thyroid examination and their guardians as well as residents, stating “It is necessary to explain (the results) to the participants with care and compassion and offer an easily comprehensible explanation to residents.”

President Ohga stated, “The thyroid examination was started in order to alleviate anxiety of residents, but it is possible the examination created (new) anxieties. It is necessary to review the examination from the standpoint of the participants.”

The Exploratory Committee, comprising the association members, is scheduled to begin discussions this fall. It will take up opinions of those diagnosed with thyroid cancer and intend to set directions before next year’s general assembly. In addition, the content of the general assembly statement will be sent to the prefectural government as a request in the future.


The statement also incorporates items regarding the response to health effects on children, long-term health management, and continuing support for children and their families who are evacuated or returning.

【Thyroid Cancer in Fukushima】How the Thyroid Examination Should Be: “Respecting a Wish Not to Participate in the Examination”

On June 15, 2016, Fukushima Minyu, one of the major regional newspapers in Fukushima Prefecture, published an article featuring Sanae Midorikawa, M.D., Ph.D., an endocrinologist who has been making school visits in Fukushima Prefecture to educate children regarding the thyroid examination they participate in. Midorikawa is also an associate professor in the Radiation Health Management at Fukushima Medical University and tasked with communication with residents. (Note: the article has been deleted from the Fukushima Minyu website. See the archived version).

The article (archived here) describes how Midorikawa is "accommodating" wishes of those children who do not want to participate in the thyroid examination that might lead to "unreasonable diagnosis of thyroid cancer." The "unreasonableness" is apparently based on the opinion of Fukushima Medical University that the thyroid cancer cases found during the first 4 years after the Fukushima Daiichi nuclear power plant accident are not due to radiation effects but simply a result of mass screening. In other words, these diagnoses are considered "unreasonable" because these cancers might never have been found until later in life without the mass screening.

It is true that cancer diagnosis can cause mental anguish and stress. When it happens to children, it is even worse since children usually do not get cancer. However, it also seems unreasonable that Fukushima Medical University is prematurely declaring "no radiation effects" for thyroid cancer cases in Fukushima children only based on the results of the first round screening. In fact, the second round screening—just completed but some results still pending—is showing more cases of thyroid cancer than explainable by "screening effect" which should not even be an issue during the second round. (See this post for the latest results.)

Although it is important to address the anxiety and fear felt by children (and their loved ones) who participate in the examination, they and their families also deserve to receive unbiased, realistic information regarding radiation risks. Yes, their exposure doses might not be as high as the Chernobyl population, but there are many uncertainties about the actual exposure doses in Fukushima. It is inferred in the recent paper by Fukushima Medical University published in Thyroid that radiation-induced thyroid cancer is not likely to appear in Fukushima because the exposure doses do not exceed 100 mSv, but this so-called 100 mSv threshold discourse has been scientifically disproven by recent studies such as the Australian CT study and the Swiss background radiation study.

The unofficial English translation of the Fukushima Minyu article  (archived here) is presented below in an attempt to share with the international community the view of a Fukushima Medical University researcher. (Addendum: FMU released an official English translation here.)

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Milepost Towards Reconstruction: Five Years of History
How the Thyroid Examination Should Be: “Respecting a Wish Not to Participate in the Examination”

“Should we leave alone the unreasonableness of being diagnosed with cancer in rare occasions after participating in an examination with unclear purposes?” 

   Beginning the last fiscal year, Sanae Midorikawa (age 48), an associate professor in the Department of Radiation Health Management at Fukushima Medical University who is in charge of communication regarding the thyroid examination, started the “demae jugyou” (translated to “delivered class” in English) geared towards children. It is because she felt it was unreasonable for many children to participate in the examination without knowing the purpose of the examination: watching over health.

   The thyroid examination targets Fukushima residents who were 18 or younger at the time of the nuclear accident. Cases of thyroid cancer have been detected among the participants, but the Fukushima Health Management Survey Oversight Committee, comprising physicians and experts, has consistently expressed an opinion that, “At the present time, they are unlikely to be due to the effect of radiation.” A possibility has been pointed out that a sensitive mass screening has detected many cases of cancer which were not previously found.

   Against the backdrop of parental concern, most children in Fukushima underwent the examination. However, Midorikawa thinks, “It is important to offer options to participate or not participate in the examination, after parents and children reach the understanding about the meaning and limitations of the examination.”

   In general, most cases of thyroid cancer are curable, and it is unlikely that thyroid  screening will lead to the merit of “reduced mortality. On the other hand, thyroid screening is not globally recommended due to the demerit of mental effects of being diagnosed with cancer. “Considering these merits and demerits, we have reached a point in time, now that five years have passed, when we need to consider how the thyroid examination should be.”

   At the delivered classes, Midorikawa explains to children about the possibility of the examination detecting cancer and tells them, “For those of you who ‘don’t want cancer diagnosis,’ your wish not to participate in the examination will be respected.” 

   In the past five years, anxiety about radiation amongst Fukushima residents took precedence over addressing the need by children to agree to participate in the examination or securing sufficient understanding of the demerits of the examination. Midorikawa reflects back, “It is not surprising that residents thought, ‘Our children should participate in the examination” after the nuclear accident. It also makes sense they connected the results with radiation and felt anxious. However, looking back, all of that was an irrational experience.”

   Unreasonableness experienced by parents and children in Fukushima Prefecture is not limited to the thyroid examination. Immediately after the accident, Chiharu Itoh (age 44), the vice principal of Fukushima Mebae Kindergarten (Fukushima City), established a one-on-one counseling room to address concerns of the mothers, dealing with various worries such as, “Should we evacuate outside Fukushima?” and “Should we avoid Fukushima products?”

   Now that five years have passed, some are beginning to voice positive opinions about the experience. “Mothers are interested in applying their experiences in adverse circumstances to the rest of their lives.” 

   Coming in contact with children during the delivered classes, Midorikawa hopes, “In the future, they will have to make important decisions regarding health risks other than radiation. It is my hope that, at such times, they will take their experiences in the past 5 years as helpful information in making a decision.

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