Fukushima Thyroid Examination April 2019: 168 Surgically Confirmed as Thyroid Cancer Among 212 Cytology Suspected Cases

*Table for The latest overall results including "unreported" cases was replaced with a corrected version showing that Age 25 Milestone Examination was conducted in FY2017, not FY2016 as stated in the original version.

  • The third round: 3 cases newly diagnosed as suspicious or malignant, and 2 new cases surgically confirmed.
  • The fourth round: 2 cases diagnosed as suspicious or malignant
  • Total number of suspected/confirmed thyroid cancer is now 211 excluding a single case of benign tumor: 115 in the first round, 71 in the second round, 21 in the third round, 2 in the fourth round, and 2 in Age 25 Milestone Screening.
  • Total number of surgically confirmed thyroid cancer cases has increased by 2 to 168 (101 in the first round, 52 in the second round, and 15 in the third round).
  • Report of the 12th Thyroid Examination Assessment Subcommittee held on February 22, 2019 shows a "new" regional (dose-response) analysis and a disagreement on incorporation of TM-NUC recommendations into a new informed consent form. 
The latest overall results including "unreported" cases
(See this post for the details of the "unreported" cases.)

Delayed timing
     On April 8, 2019, the 34th Oversight Committee for Fukushima Health Management Survey (FHMS) convened in Fukushima City, Fukushima Prefecture. This was the "later-than-usual" first meeting of the quarterly Oversight Committee meetings to be held in 2019: first meetings of each calendar year which correspond to last meetings of each fiscal year ending March 31 have mostly been held in February (one in early March) reporting results as of December 31 of the previous year. Fiscal reports as of March 31 are usually released at the second meeting of each calendar year corresponding to the first meeting of each fiscal year usually held in mid-May to mid-June. There is a concern that delayed timing of the 34th Oversight Committee meeting could interfere with "timely" reporting of the final results of the 3rd round.
     Among other information, the Oversight Committee released the latest results (as of December 31, 2018) of the third and fourth rounds of the Thyroid Ultrasound Examination (TUE). Official English translation will be available here in the hopefully "near" future. (Note: English translation for the December 27, 2018 meeting was posted online on April 5, 2019.)

Summary on the current status of the TUE
     A five-page summary of the first through fourth rounds as well as the Age 25 Milestone Screening, "The Status of the Thyroid Ultrasound Examination," was also released, listing key findings from the primary and confirmatory examinations as well as the surgical information. This summary is not translated into English officially, but here's an unofficial translation. 

Report from the 12th Thyroid Examination Assessment Subcommittee
     Chair of the Thyroid Examination Assessment Subcommittee (herein, subcommittee), Gen Suzuki, reported the content of the 12th subcommittee held on February 22, 2019. Suzuki's report is summarized here.
     Notably, Fukushima Medical University (FMU) reported a new analysis on associations between thyroid cancer occurrence in 2 age groups (6-14, ≥15) and minimum and maximum values of estimated thyroid absorption doses by UNSCEAR, concluding no observation of dose response. (However, an astrophysicist Junichiro Makino has questioned scientific validity of the analysis itself in April-June 2019 issues of Kagakupointing out inconsistencies between the original data and the 95% CI shown in graphs and between the results of this analysis and a previously published paper.)
     Discussions regarding risks and benefits of the TUE have long been incongruous. On September 28, an IARC expert group, Thyroid Monitoring after Nuclear Accidents (TM-NUC) released the first report as an IARC publication, followed by an article in the October 1, 2018 issue of the Lancet Oncology and the second report in March. (See this post on the "birth" of TM-NUC.) 
    The TUE informed consent form is currently undergoing revision to better inform participants of the risks and benefits. During the 12th subcommittee meeting, the discussion reached a new level of dichotomy between pubic health specialists wanting to use as the TM-NUC recommendations (summarized here) as evidence for overdiagnosis risks and clinicians doubting the evidence level of the TM-NUC report which is built on known-to-be-scarce evidence of pediatric thyroid cancer.
     As a matter of fact, TM-NUC's first report is not intended to guide how Fukushima's TUE should be implemented as described by TM-NUC chair Joachim Schüz during the press conference after the March 7, 2019 symposium in Tokyo sponsored by Ministry of the Environment and moderated by none other than Shunichi Yamashita to introduce the report. 
    The first report does incorporate findings from Fukushima's TUE by necessity, as data from one of the three nuclear accidents. Its section on "Overdiagnosis in Pediatric Thyroid Cancer" relies heavily on published papers on Fukushima's TUE, yet most of the published papers on the TUE are inherently biased. This is partly because the publicized data itself is incomplete and lacks transparency and partly due to the premature and scientifically unfounded premise by FMU to dismiss effects of radiation exposure before conducting a proper analysis on data beyond the first round. This topic is to be covered in a separate post, time permitted.

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