Fukushima Thyroid Examination October 2021: 221 Surgically Confirmed as Thyroid Cancer Among 266 Cytology Suspected Cases


Overview

    On October 15, 2021, the 43rd session of the Oversight Committee for the Fukushima Health Management Survey (FHMS) convened online and in Fukushima City, releasing a new set of results (data up to June 30, 2021) from the fourth and fifth rounds of the Thyroid Ultrasound Examination (TUE).  The fifth-round data reported this time includes the confirmatory examination results. In addition, a corrected version of the results was released for the Age 25 Milestone Screening originally reported in July 2021. 

    The 43rd session was the first session of a new two-year term (August 2021-July 2023) for 18 committee members, including 6 new members. (Regrettably, a long-time committee member Fumiko Kasuga, who steadfastly advocated for release of more clinical information as well as inclusion of feedbacks from participants and their families, is no longer included.)  A roster for the Thyroid Examination Evaluation Subcommittee was also released, but there was no change. It was revealed that there was no target date for the release of an interim summary for the third round.

   At this time, an official English translation is available up to the 40th session of the Oversight Committee on the website for the Radiation Medical Science Center of the Fukushima Health Management Survey (RMSC/FHMS). The final results of the third round, released at the 39th session in August 2020, is finally available in English on pages 2-20 of this report.

   
Highlights
  • The fourth round: 3 new cases diagnosed as suspicious or malignant, and 2 new surgical cases. 
  • The fifth round: 3 new cases diagnosed as suspicious or malignant, and 1 new surgical case
  • Total number of suspected/confirmed thyroid cancer has increased by 6 to 266116 in the first round (including a single case of benign tumor), 71 in the second round, 31 in the third round, 36 in the fourth round, 3 in the fifth round, and 9 in Age 25 Milestone Screening.
  • Total number of surgically confirmed thyroid cancer cases has increased by 3 to 221 (101 in the first round, 55 in the second round, 29 in the third round, 29 in the fourth round, 1 in the fifth round, and 6 in Age 25 Milestone Screening,

The latest overall results including the "unreported" and cancer registry cases
    Please refer to the previous post regarding details of "unreported" cases and cancer registry data.

    Official count, as reported in the summary document shown in the next section, is 266 suspected/confirmed and 221 surgically confirmed thyroid cancer cases. An addition of more recent "unreported" cases as well as "outside" cases discovered in cancer registry makes the count a little more complete with 325 cytologically suspected/confirmed and 264 surgically confirmed cancer cases. It should be noted that the actual number of cases is likely more than these as no exhaustive investigation has been and will be conducted by FMU to fully report all the cancer cases discovered outside the framework of the FHMS-TUE.


Summary on the current status of the TUE
    A six-page summary of the first through fifth rounds as well as the Age 25 Milestone Screening, "The Status of the Thyroid Ultrasound Examination Results," lists key findings from the primary and confirmatory examinations as well as the surgical information. 
    Below is an unofficial translation of this summary which is not officially translated.


The fourth round
    For the still ongoing fourth round, originally scheduled from April 1, 2018 through March 31, 2020, only 54 participated in the primary examination between April 2, 2021 and June 30, 2021, with an unchanged participation rate of 
62.3%. (Note: This is still below what the prior rounds registered (81.7% for the first round, 71.0% for the second round, and 64.7% for the third round), although it is slowly approaching the third round.)

    Having received the "B" assessment in the primary examination, 8 newly became eligible for the confirmatory examination. With mere 7 participants newly participating, the confirmatory examination increased its participation rate 0.1% to 73.4%. Out of 5 participants newly undergoing FNAC, 3 individuals (2 males and 1 female) were diagnosed with suspected thyroid cancer. Their third-round results were 1 with A2 cyst and 2 with B. Two males were ages 8 and 14 and the female was age 9 at the time of the 2011 nuclear accident. Both males are from the FY 2018 municipalities, and the single female is from the FY 2019 municipalities. Two are from Nakadori and one is from Hamadori. 

   Two more cases from the FY 2019 municipalities were newly confirmed with papillary thyroid cancer after undergoing surgery.  

    In summary, as of June 30, 2021, the number of suspected or confirmed thyroid cancer cases for the fourth round is 36, of which 29 have been surgically confirmed as papillary thyroid cancer. 

    The previous results from the third round are as follows: 25 with "A" (6 with A1, 13 with A2 cysts, 5 with A2 nodules, and 1 with A2 cysts and nodules), 8 with "B," and 3 with no prior result. 


The fifth round
    The fifth round targets 252,842 individuals, excluding about 21,000 born in FY 1996 (April 2, 1996 to April 1, 1997) and about 20,000 born in FY 1997 (April 2, 1997 to April 1, 1998) who are earmarked for the Age 25 Milestone Examination in FY 2021-2022. (The previous post discussed how this exclusion skews age distribution graphs to the left.)

    The COVID-19 restrictions have had a significant impact on the progress of the fifth round which began in April 2020: school closures initially halted the school-based screening, and a burden on medical facilities reduced participation in the confirmatory examination. [Note: The fifth round was originally earmarked for FY 2020-2021 (April 2, 2020 to March 31, 2022), but the pandemic impact has forced an extension of the screening period by one year as described in this proposal: Elementary and middle school students from FY 2020 municipalities will undergo the TUE in FY 2020-2021, while FY 2021 municipalities will be pushed to FY 2022. For high school students, the TUE will be conducted in FY 2021-2022 with the exception of those who were already examined in FY 2020.]

     As of June 30, 2021, 32,404 participated in the primary examination, including 8,992 new participants, and its participation rate increased from 9.3% to 12.8%, still quite low. Participation rates by age group are 24.2% in ages 8-11, 13.1% in ages 12-17, and 5.2% in ages over 18, showing a slow but steady progress of school-bases examination. The primary examination results are available for 24,882 (76.8%), and 291 (68 more) were assessed as "B" qualifying for the confirmatory examination. 

   One hundred seventy-five out of 291 have participated in the confirmatory examination, and 7 underwent FNAC which diagnosed 3 females with suspected thyroid cancer. Ages and average tumor diameter weren't available for these three, due to a small number of cases. Likely for the same reason, their prior screening results were also not released. Two are from the FY 2020 municipalities and one is from the FY 2021 municipalities. 

   The single case from the FY 2021 municipalities has been confirmed with papillary thyroid cancer after undergoing surgery.


Age 25 Milestone Screening results corrected
    
    No new results were released for the Age 25 Milestone Screening, but the confusion on the prior screening result of the single new case reported last time was clarified. She tested as "B" in the prior screening as reported verbally, and a corrected version of the results was released. Also, the single A2 case was confirmed to be nodule. 

   The results from the prior screening for 9 suspected or confirmed cases are: 1 with A2 nodule, 2 with "B," and 6 with no prior screening.

    
Summary of the results from the previous screening 
    Below is the summary of the previous screening results for the suspected/confirmed thyroid cancer cases. This information, already mentioned above except for the second round, can be difficult to locate in print. In particular, a breakdown of the "A2" assessment is only verbally reported during the Oversight Committee sessions. 

Definition
"A1": no ultrasound findings. 
"A2": ultrasound findings of nodules ≤ 5.0 mm and/or cysts ≤ 20.0 mm. 
"B": ultrasound findings of nodules  5.1 mm and/or cysts  20.1 mm.

    Having previous assessments of "A1" or "A2 cysts" means there were no precancerous lesions during the previous screening, i.e., cancer supposedly appeared since the previous screening. (Note: FMU claims that the cancerous lesions did not newly appear but already existed yet "invisible" during the previous screening.)
  • Second round (71 cases): 33 cases with A1, 32 cases with A2 (7 nodules and 25 cysts), 5 cases with B, 1 case previously unexamined
  • Third round (31 cases):  7 cases with A1, 14 cases with A2 (4 nodules and 10 cysts), 7 cases with B, 3 cases previously unexamined
  • Fourth round (36 cases): 6 cases with A1, 19 cases with A2 (5 nodules, 13 cysts, and 1 nodule & cyst), 8 cases with B, 3 cases previously unexamined
  • Age 25 Milestone Screening (9 cases): 1 case with A2 (nodule), 2 cases with B, 6 cases previously unexamined
      
  

Fukushima Thyroid Examination July 2021: 218 Surgically Confirmed as Thyroid Cancer Among 260 Cytology Suspected Cases


Overview

    On July 27, 2021, the 42nd session of the Oversight Committee for the Fukushima Health Management Survey (FHMS) convened online and in Fukushima City, releasing a new set of results (data up to March 31, 2021) from the Thyroid Ultrasound Examination (TUE). The main results reported this time are for the fourth and fifth rounds as well as the Age 25 Milestone Screening. In addition, March 31st marks the end of fiscal year in Japan prompting a release of fiscal year-end reports, which included an updated version of the second-round results and a FY 2020 supplementary version for the third round.

    The 42nd session, held only two months after the last session, was the final session for this group of committee members whose two-year term concluded on July 31, 2021. It was also held a month after the 17th session of the Thyroid Examination Evaluation Subcommittee (herein the TUE Subcommittee), which was also the final session of the two-year term for the subcommittee members. Although the TUE Subcommittee was discussing analytical results of the third-round data, no "interim summary" has been drawn up.

     The Oversight Committee sessions were only held three times during FY 2018 and 2020, rather than quarterly as specified in the implementation guidelines. The data gap created during FY 2020 with 3-month worth of data reported every 4 months was "closed" this time with a report of 6-month worth of data. With the 43rd session scheduled to be held on October 15, 2021, the Oversight Committee appears to be back on regular schedule at least for the current fiscal year 2021.

    The pandemic restrictions are still hampering the progress of the fifth round: Once again, the confirmatory examination results were not reported.

   At this time, an official English translation is available up to the 40th session of the Oversight Committee on the website for the Radiation Medical Science Center of the Fukushima Health Management Survey (RMSC/FHMS). This means that the final results of the third round, released at the 39th session in August 2020, is finally available in English on pages 2-20 of this report.

   
Highlights
  • The second round: 1 new surgical case.
  • The third round: 2 new surgical cases.
  • The fourth round: 3 new cases diagnosed as suspicious or malignant, and 2 new surgical cases. 
  • The fifth round: no report on the confirmatory examination.
  • The Age 25 Milestone Screening: 1 new case diagnosed as suspicious or malignant, and no new surgical cases.
  • Total number of suspected/confirmed thyroid cancer has increased by 4 to 260116 in the first round (including a single case of benign tumor), 71 in the second round, 31 in the third round, 33 in the fourth round, and 9 in Age 25 Milestone Screening.
  • Total number of surgically confirmed thyroid cancer cases has increased by 5 to 218 (101 in the first round, 55 in the second round, 29 in the third round, 27 in the fourth round, and 6 in Age 25 Milestone Screening,

The latest overall results including the "unreported" and cancer registry cases
    Please refer to the previous post regarding details of "unreported" cases and cancer registry data.

    Official count, as reported in the summary document shown in the next section, is 260 suspected/confirmed and 218 surgically confirmed thyroid cancer cases. An addition of more recent "unreported" cases as well as "outside" cases discovered in cancer registry makes the count a little more complete with 319 cytologically suspected/confirmed and 261 surgically confirmed cancer cases. It should be noted that the actual number of cases is likely more than these as no exhaustive investigation has been and will be conducted by FMU to fully report all the cancer cases discovered outside the framework of the FHMS-TUE.



Summary on the current status of the TUE
    A six-page summary of the first through fifth rounds as well as the Age 25 Milestone Screening, "The Status of the Thyroid Ultrasound Examination Results," lists key findings from the primary and confirmatory examinations as well as the surgical information. 
    Below is an unofficial translation of this summary which is not officially translated.


The second round  

   An updated version of the second-round results was released at the end of FY 2020 reflecting slight changes in the number of participants and test results since the FY 2017 supplementary version. Corrections were also made for female proportions of the primary examination participants which were erroneously reported as female proportions of the target population. Similar corrections were made for the first-round results, but its updated version was posted as a replacement for the FY 2017 condensed version which is the most recent condensed version of the first-round results.

   The number of suspected thyroid cancer remains the same at 71, but with an addition of one new surgical case which turned out to be a papillary thyroid cancer, the number of confirmed cancer cases now stands at 55 including 54 papillary thyroid cancers and 1 other cancer.

The third round

   For the third-round results, a FY 2020 supplementary version of the final results was released to reflect changes in the numbers of participants and test results since the final results were reported in the summer of 2020. The number of suspected thyroid cancer cases remains the same at 31, but an addition of 2 surgical cases increases the number of confirmed thyroid cancer cases to 29, all papillary thyroid cancers.

   An official English translation of the final results of the third round is available here. 

The fourth round
    Although the fourth round, originally scheduled from April 1, 2018 through March 31, 2020, is still ongoing, only 442 participated in the primary examination between September 30, 2020 and March 31, 2021, slightly raising the current participation rate by 0.2
to 62.3%. This is still below what the prior rounds registered (81.7% for the first round, 71.0% for the second round, and 64.7% for the third round), although it is slowly approaching the third round.

    Having received the "B" assessment in the primary examination, 9 newly became eligible for the confirmatory examination. With an additional 86 participants, the confirmatory examination increased its participation rate by 5.8% to 73.3%. Out of 8 participants newly undergoing FNAC, 3 individuals (2 males and 1 female) were diagnosed with suspected thyroid cancer. Their third-round results were A1, B, and no previous examination. Two males were ages 8 and 9 and the female was age 8 at the time of the 2011 nuclear accident. One of the males is from the FY 2018 municipalities, and the other male and the female are from the FY 2019 municipalities. One is from Nakadori and two are from Hamadori. 

     Two more cases (one from the FY 2018 municipalities and one from the FY 2019 municipalities) were newly confirmed with papillary thyroid cancer after undergoing surgery.  

    In summary, as of March 31, 2021, the number of suspected or confirmed thyroid cancer cases for the fourth round is 33, of which 27 have been surgically confirmed as papillary thyroid cancer. 

    The previous results from the third round are as follows: 24 with "A" (6 with A1, 12 with A2 cysts, 5 with A2 nodules, and 1 with A2 cysts and nodules), 6 with "B," and 3 with no prior result. 

The fifth round
    The fifth round targets 252,842 individuals, excluding about 21,000 born in FY 1996 (April 2, 1996 to April 1, 1997) and about 20,000 born in FY 1997 (April 2, 1997 to April 1, 1998) who are earmarked for the Age 25 Milestone Examination in FY 2021-2022. (The previous post discussed how this exclusion skews age distribution graphs to the left.)

    The COVID-19 restrictions have had a significant impact on the progress of the fifth round which began in April 2020: school closures initially halted the school-based screening, and a burden on medical facilities reduced participation in the confirmatory examination. 

     As of March 31, 2021, 23,412 participated in the primary examination, including 20,342 new participants, and its participation rate increased from 1.2% to 9.3%, still quite low. Participation rates by age group are 16.4% in ages 8-11, 9.7% in ages 12-17, and 4.2% in ages over 18, showing a slow progress of school-bases examination. The primary examination results are available for 21,624 (92.4%), and 228 were assessed as "B" qualifying for the confirmatory examination. Once again, no confirmatory examination results were reported due to a very small number of participants.

    The fifth round was originally earmarked for FY 2020-2021 (April 2, 2020 to March 31, 2022), but the pandemic impact has forced an extension of the screening period by one year as described in this proposal: Elementary and middle school students from FY 2020 municipalities will undergo the TUE in FY 2020-2021, while FY 2021 municipalities will be pushed to FY 2022. For high school students, the TUE will be conducted in FY 2021-2022 with the exception of those who were already examined in FY 2020.

Age 25 Milestone Screening
    In the Age 25 Milestone Screening, each screening year targets a cohort turning 25 during each fiscal year, and the results are reported every 6 months. Implementation schedule as of September 30, 2018, reported to the 33rd session of the Oversight Committee, can be found here. (No one is supposed to undergo a regular TUE within 2 years of becoming eligible for the Age 25 Milestone Screening.)

    Transition of each FY birth cohort to the Age 25 Milestone Screening reduces a target population for the main TUE. This reduction began in the third round conducted during FY 2016-2017, which excluded the FY 1992 and 1993 cohorts in anticipation of the upcoming Age 25 Milestone Screening. With each FY birth cohort including about 22,000 individuals, this is a sizable reduction which continues as the TUE target population ages. For example, the target population has gone from 367,637 for the first round, to 381,237 for the second round (increased because those who were in utero at the time of the accident were included),  336,667 for the third round, 294,239 for the fourth round, and now 252,842 for the fifth round.

    The results reported this time are from the data up to March 31, 2021, newly including 21,056 who were born in FY1995 in the target population. Since the previously reported results as of September 30, 2020, 1,667 more participated in the primary examination, with total participants being 7,612,  A participation rate actually saw a slightly decrease by 0.2% to 8.7%, due to the increased target population of 87,694. Although each fiscal-year screening is earmarked for those turning 25 during that fiscal year, participants can take part in the screening anytime up to the year before they become eligible for the Age 30 Milestone Screening. Thus participation rates by FY birth cohorts might continue to change as the screening progresses. 

    Seventy-eight more became eligible for the confirmatory examination (a.k.a. "B" assessment in the primary examination). Of 359 qualifying for the confirmatory examination, 239 have undergone it, with 18 newly participating. Only one person newly underwent FNAC, and this person, a female, was diagnosed with suspected thyroid cancer. There was a confusion about her prior result, which was verbally reported as no prior examination while the written report shows it was A2. Curiously, the verbal report specified one prior A2 case as nodule, whereas an existing prior A2 case never had clarification as to whether it was cyst or nodule. 

    Thus the number of suspected or confirmed thyroid cancer cases from the Age 25 Milestone Screening increased by 1 to 9. The results from the prior screening have two possibilities depending on which information is accurate, verbal or written. (Note on October 15, 2021: the verbal information was accurate, and a corrected version of the report was released.)
a) verbal: 1 with A2 nodule, 2 with "B," and 6 with no prior screening.
b) written: 2 with A2 (at least one with nodule according to the verbal report), 2 with "B," and 5 with no prior screening.

    No new surgical cases were added, and surgically confirmed thyroid cancer cases remain as 6, including 5 papillary thyroid cancers and 1 follicular thyroid cancer.

    
Summary of the results from the previous screening 
    Below is the summary of the previous screening results for the suspected/confirmed thyroid cancer cases. This information, already mentioned above except for the second round, can be difficult to locate in print. In particular, a breakdown of the "A2" assessment is only verbally reported during the Oversight Committee sessions. 

Definition
"A1": no ultrasound findings. 
"A2": ultrasound findings of nodules ≤ 5.0 mm and/or cysts ≤ 20.0 mm. 
"B": ultrasound findings of nodules  5.1 mm and/or cysts  20.1 mm.

    Having previous assessments of "A1" or "A2 cysts" means there were no precancerous lesions during the previous screening, i.e., cancer supposedly appeared since the previous screening. (Note: FMU claims that the cancerous lesions did not newly appear but already existed yet "invisible" during the previous screening.)
  • Second round (71 cases): 33 cases with A1, 32 cases with A2 (7 nodules and 25 cysts), 5 cases with B, 1 case previously unexamined
  • Third round (31 cases):  7 cases with A1, 14 cases with A2 (4 nodules and 10 cysts), 7 cases with B, 3 cases previously unexamined
  • Fourth round (33 cases): 6 cases with A1, 18 cases with A2 (5 nodules, 12 cysts, and 1 nodule & cyst), 6 cases with B, 3 cases previously unexamined
  • Age 25 Milestone Screening (9 cases): Due to inconsistencies between verbal and written reports, both scenarios are listed below. (Note on October 15, 2021: the verbal information was accurate, and a corrected version of the report was released.)
         Verbal report: 1 case with A2 (nodule), 2 cases with B, 6 cases previously unexamined
         Written report: 2 cases with A2 (1 nodule and 1 unknown?), 2 cases with B, 5 cases previously unexamined

  

Fukushima Thyroid Examination May 2021: 213 Surgically Confirmed as Thyroid Cancer Among 256 Cytology Suspected Cases

 


Overview

    On May 17, 2021, the 41st session of the Oversight Committee for the Fukushima Health Management Survey (FHMS) convened online and in Fukushima City, releasing a new set of results (data up to September 30, 2020) from the Thyroid Ultrasound Examination (TUE).  The results reported this time are for the fourth and fifth rounds as well as the Age 25 Milestone Screening

    The 41st session was held four months after the last session, and it appears that it has become "regular" to hold the Oversight Committee sessions three times a year rather than quarterly as specified in the implementation guidelines. With the data released at each session only including 3 months worth of results while sessions held every 4 months since 2019, a data gap keeps increasing. A spring session such as this used to report data up to March 31, which is the end of a fiscal year in Japan, but now we are 6 months behind on data release.

    The pandemic restrictions are still slowing the fifth round, and no results were reported for the confirmatory examination of the fifth round, which has only been sparsely conducted.

   
Highlights
  • The fourth round: 3 new cases diagnosed as suspicious or malignant, and 9 new surgical cases. 
  • The fifth round: no report on the confirmatory examination.
  • The Age 25 Milestone Screening: 1 new case diagnosed as suspicious or malignant, and 2 new surgical cases.
  • Total number of suspected/confirmed thyroid cancer has increased by 4 to 256116 in the first round (including a single case of benign tumor), 71 in the second round, 31 in the third round, 30 in the fourth round, and 8 in Age 25 Milestone Screening.
  • Total number of surgically confirmed thyroid cancer cases has increased by 11 to 213 (101 in the first round, 54 in the second round, 27 in the third round, 25 in the fourth round, and 6 in Age 25 Milestone Screening)
  • Data reported is as of September 30, 2020. (Delayed reporting persists after the fourth quarterly session was skipped in 2019, 2020, and now likely 2021.)
  • A list of official English translation of the FHMS reports including the TUE results is available on the website for the Radiation Medical Science Center of the Fukushima Health Management Survey (RMSC/FHMS). At this time, translation is available for the first two 2020 sessions, the 37th and 38th sessions. The final results of the third round, released at the 39th session in August 2020, is not yet available in English.

The latest overall results including the "unreported" and cancer registry cases
    The table below shows a new set of numbers for "unreported" cases: 35 malignant or suspicious, 35 surgical, and 19 cancer cases (previously 12, 12, and 11, respectively, as explained here and reported in this paper). These 35 cases are part of 180 surgical cases operated at the Fukushima Medical University (FMU) hospital as of December 31, 2018: unlike other 145, they had not been included in a report to the Oversight Committee,
    Shinichi Suzuki, an FMU thyroid surgeon, has presented this data at various domestic and international academic meetings since 2019 including a February 3, 2020 keynote lecture at the Second International Symposium by RMSC/FHMS. More than a year later, it finally became part of the official TUE data when it was reported to the 16th TUE Subcommittee held on March 22, 2021. (Note: This report is merely an excerpt from a symposium abstract. The English abstract can be accessed here.)  There is no way to confirm, but it is assumed that previous 12 unreported malignant/suspicious cases, of which 11 are confirmed as cancer, are likely included in these 35 cases.

    There is also a new row added to the table, showing 24 thyroid cancer cases which were diagnosed outside the framework of the TUE but found in Fukushima Prefecture's cancer registry from 2012 to 2017. This was also reported at the 16th TUE Subcommittee.

    Official count, as reported in the summary document shown in the next section, is 256 suspected/confirmed and 213 surgically confirmed thyroid cancer cases. An addition of more recent "unreported" cases as well as "outside" cases discovered in cancer registry makes the count a little more complete with 315 cytologically suspected/confirmed and 256 surgically confirmed cancer. It should be noted that the actual number of cases is likely more than these.


Summary on the current status of the TUE
    A six-page summary of the first through fifth rounds as well as the Age 25 Milestone Screening, "The Status of the Thyroid Ultrasound Examination Results," lists key findings from the primary and confirmatory examinations as well as the surgical information. 
    Below is an unofficial translation of this summary which is not officially translated.



The fourth round
    The fourth round, originally scheduled from April 1, 2018 through March 31, 2020, is still ongoing. Between June 30, 2020 and September 30, 2020, the primary examination gained 1,851 more participants, raising the current participation rate by 0.6
to 62.1%. An important reminder: This is still below what the prior rounds registered (81.7% for the first round, 71.0% for the second round, and 64.7% for the third round), although it is slowly approaching the third round.
    Having received the "B" assessment in the primary examination, 12 newly became eligible for the confirmatory examination. With an additional 109 participants, the confirmatory examination increased its participation rate by 7.4% to 67.5%. Out of 10 participants newly undergoing FNAC, 3 individuals (1 male and 2 females) were diagnosed with suspected cancer. Their third-round results were 2 with A2 (1 nodule and 1 nodule & cyst) and 1 with no previous examination. The male was age 9 and the females were age 5 and 9 at the time of the 2011 nuclear accident. All three are from the FY 2019 municipalities, and two are from Hamadori and one is from Aizu. 
    Nine more cases (two from the FY 2018 municipalities and seven from the FY 2019 municipalities) were newly confirmed with papillary thyroid cancer after undergoing surgery.  

    In summary, as of September 30, 2020, the number of suspected or confirmed thyroid cancer cases for the fourth round is 30, of which 25 have been surgically confirmed as thyroid cancer: all papillary thyroid cancer. 

    The previous results from the third round are as follows: 23 with "A" (5 with A1, 12 with A2 cysts, 5 with A2 nodules, and 1 with A2 cysts and nodules), 5 with "B," and 2 with no prior result. 


The fifth round
    The fifth round targets 252,828 individuals, excluding about 21,000 born in FY 1996 (April 2, 1996 to April 1, 1997) and about 20,000 born in FY 1997 (April 2, 1997 to April 1, 1998) who are earmarked for the Age 25 Milestone Examination in FY 2021-2022. (The previous post discussed how this exclusion skews age distribution graphs to the left.)
    The COVID-19 restrictions significantly impacted progress of the fifth round which began in April 2020: school closures initially halted the school-based screening, and a burden on medical facilities reduced participation in the confirmatory examination. As of September 30, 2020, 3,070 participated in the primary examination, including 2,506 new participants, but its participation rate remains extremely low at 1.2%. Of 2,506 new participants about half is in the age 8-17 category (571 in age 8-11 and 678 in age 12-17), and the other half in the age 18-24 category. The primary examination results are available for 2,138 (69.8%), and a total of 26 were assessed as "B."

    Because very few had undergone the confirmatory examination as of September 30, 2020, the results were not reported at this time.

    The fifth round was originally earmarked for FY 2020-2021 (April 2, 2020 to March 31, 2022), but the pandemic impact has forced an extension of the screening period by one year as described in this proposal: Elementary and middle school students from FY 2020 municipalities will undergo the TUE in FY 2020-2021, while FY 2021 municipalities will be pushed to FY 2022. For high school students, the TUE will be conducted in FY 2021-2022 with the exception of those who were already examined in FY 2020.

Age 25 Milestone Screening
    In the Age 25 Milestone Screening, each screening year targets a cohort turning 25 during each fiscal year, and the results are reported every 6 months. Implementation schedule as of September 30, 2018, reported to the 33rd session of the Oversight Committee, can be found hereNo one is supposed to undergo the regular TUE within 2 years of becoming eligible for the Age 25 Milestone Screening.

    Transition of each FY birth cohort to the Age 25 Milestone Screening reduces a target population for the main TUE. This reduction began in the third round conducted during FY 2016-2017, which excluded the FY 1992 and 1993 cohorts in anticipation of the upcoming Age 25 Milestone Screening. With each FY birth cohort including about 22,000 individuals, this is a sizable reduction which continues as the TUE target population ages. For example, the target population has gone from 367,637 for the first round, to 381, 244 for the second round (increased because those who were in utero at the time of the accident were included),  336,670 for the third round, 294,242 for the fourth round, and now 252,828 for the fifth round.

    The results reported this time are from the data up to September 30, 2020. Since the previously reported results as of March 31, 2020, 376 more participated in the primary examination, but the total participants are 5,954 out of the target population of 66,637, and an overall participation rate only slightly increased by 0.5% to 8.9%, conspicuously much lower than the main TUE. Although each fiscal-year screening is earmarked for those turning 25 during that fiscal year, participants can take part in the screening anytime up to the year before they become eligible for the Age 30 Milestone Screening. Thus participation rates by FY birth cohorts might continue to change as the screening progresses. 

    Thirty-seven more became eligible for the confirmatory examination (a.k.a. "B" assessment in the primary examination). Of 281 needing the confirmatory examination, 221 has undergone it, with 53 newly participating. Three newly underwent FNAC, and one female with a prior result of "B" was diagnosed with suspected thyroid cancer.

    Thus the number of suspected or confirmed thyroid cancer cases from the Age 25 Milestone Screening increased by 1 to 8. The results from the prior screening are as follows: 1 with A2 (unclear if cyst or nodule due to lack of reporting), 2 with "B," and 5 with no prior screening.

    With an addition of 2 new surgical cases, a total of 6 thyroid cancer cases (5 papillary thyroid cancers and 1 follicular thyroid cancer) were surgically confirmed in the Age 25 Milestone Screening.

    
Summary of the results from the previous screening 
    Below is the summary of the previous screening results for the suspected/confirmed thyroid cancer cases. This information, already mentioned above except for the second round, can be difficult to locate in print. In particular, a breakdown of the "A2" assessment is only verbally reported during the Oversight Committee sessions. 

Definition
"A1": no ultrasound findings. 
"A2": ultrasound findings of nodules ≤ 5.0 mm and/or cysts ≤ 20.0 mm. 
"B": ultrasound findings of nodules  5.1 mm and/or cysts  20.1 mm.

    Having previous assessments of "A1" or "A2 cysts" means there were no precancerous lesions during the previous screening, i.e., cancer supposedly appeared since the previous screening. (Note: FMU claims that the cancerous lesions did not newly appear but already existed yet "invisible" during the previous screening.)
  • Second round (71 cases): 33 cases with A1, 32 cases with A2 (7 nodules and 25 cysts), 5 cases with B, 1 case previously unexamined
  • Third round (31 cases):  7 cases with A1, 14 cases with A2 (4 nodules and 10 cysts), 7 cases with B, 3 cases previously unexamined
  • Fourth round (30 cases): 5 cases with A1, 18 cases with A2 (5 nodules, 12 cysts, and 1 nodule & cyst), 5 cases with B, 2 cases previously unexamined
  • Age 25 Milestone Screening (8 cases): 1 case with A2 (it was never reported if nodule or cyst), 2 cases with B, 5 cases previously unexamined
  




Fukushima Thyroid Examination January 2021: 202 Surgically Confirmed as Thyroid Cancer Among 252 Cytology Suspected Cases

 

   After a 4½-month hiatus, the 40th session of the Oversight Committee was held on January 15, 2021, releasing new data (as of June 30, 2020) from the fourth and fifth rounds of the Thyroid Ultrasound Examination (TUE). The pandemic restrictions have essentially stalled the school-based screening for the fifth round, and the only cancer data updated was that of the fourth round.

   
Highlights
  • The fourth round: 6 new cases diagnosed as suspicious or malignant, and 3 new surgical cases. 
  • Total number of suspected/confirmed thyroid cancer has increased by 6 to 252116 in the first round (including a single case of benign tumor), 71 in the second round, 31 in the third round, 27 in the fourth round, and 7 in Age 25 Milestone Screening.
  • Total number of surgically confirmed thyroid cancer cases has increased by 4 to 202 (101 in the first round, 54 in the second round, 27 in the third round, 16 in the fourth round, and 4 in Age 25 Milestone Screening)
  • Data reported is as of June 30, 2020. (Delayed reporting persists after the fourth quarterly session was skipped in 2019 and now also in 2020.)
  • A list of official English translation of the TUE results is available on the website for the Radiation Medical Science Center of the Fukushima Health Management Survey. No translation is available for the 2020 sessions at this time. 

The latest overall results including the "unreported" cases

(See this post for description of the "unreported" cases. 
Histological diagnosis of the 11 unreported cancer cases was obtained from this paper.)

Overview
     On January 15, 2021, the 40th session of the Oversight Committee for the Fukushima Health Management Survey (FHMS) convened in Fukushima City, Fukushima Prefecture to release data as of June 30, 2020. As the third round results were finalized 7 months ago and the fifth round just began in April 2020, new information released on thyroid cancer was essentially from the fourth round only. 

Summary on the current status of the TUE
     A six-page summary of the first through fifth rounds as well as the Age 25 Milestone Screening, "The Status of the Thyroid Ultrasound Examination," lists key findings from the primary and confirmatory examinations as well as the surgical information. 
     Below is an unofficial translation of this summary which is not officially translated.



The fourth round
   The fourth round, scheduled from April 1, 2018 through March 31, 2020, is still ongoing. Between April 1, 2020 and June 30, 2020, the primary examination gained only 435 more participants, raising the current participation rate by 0.1
to 61.5%. A reminder: This is still below what the prior rounds registered (81.7% for the first round, 71.0% for the second round, and 64.7% for the third round), although it is approaching the third round.
  Having received the "B" assessment in the primary examination, 35 newly became eligible for the confirmatory examination. With an additional 78 actually participating,  the participation rate increased by 4.3% to 60.1%. Out of 15 participants undergoing FNAC, 6 females were diagnosed with suspected cancer. Their third-round results include 2 with A1, 2 with A2 (1 cyst and 1 nodule), 1 with B, and 1 with no previous examination. Their ages at the time of the 2011 nuclear accident are 0, 2, 6, 6, 10 and 11. It is notable that this marks the first time that thyroid cancer was detected in individuals aged 0 and 2 at the time of radiation exposure. Two are from Nakadori, one is from Hamadori, and remaining three are from Aizu. One is from a FY 2018 municipality, and the rest from FY 2019 municipalities.
   Three more case(all from FY 2019 municipalities) were newly confirmed with papillary thyroid cancer after undergoing surgery.   

   In summary, as of June 30, 2020, the number of suspected or confirmed thyroid cancer cases for the fourth round is 27, and 16 have been surgically confirmed as thyroid cancer, all papillary thyroid cancer. 
   The previous results from the third round are as follows: 21 with "A" (5 with A1, 12 with A2 cysts, and 4 with A2 nodules), 5 with "B," and 1 with no prior result. 


The fifth round
   The fifth round targets 252,821 individuals, excluding about 21,000 born in FY 1996 (April 2, 1996 to April 1, 1997) and about 20,000 born in FY 1997 (April 2, 1997 to April 1, 1998) who are earmarked for the Age 25 Milestone Examination in FY 2021-2022. (See the next section to learn what this exclusion means for the age distribution graphs.)
  Although the fifth round began in April 2020, its progress has been hampered by school closures and other restrictions due to the COVID-19 pandemic. As of June 30, 2020, only 564 participated in the primary examination with 487 (86.3%) in the age 18-24 category. Due to cancellation of the school-based screening in accordance with school closures, only 77 participated in the younger age group (8-17). The primary examination results are available for only 41 out of 564, and one person was assessed as "B."
   No confirmatory examination has been conducted as of June 30, 2020, and there are no suspected/confirmed cancer cases for the fifth round at this time.

   Because of the pandemic delay, a proposal was submitted by FMU to extend a two-year screening cycle to three years just for the fifth round. Elementary and middle school students from FY 2020 municipalities will undergo the TUE in FY 2020-2021, while FY 2021 municipalities will be pushed to FY 2022. For high school students, the TUE will be conducted in FY 2021-2022 with the exception of those already examined in FY 2020.

Age distribution graphs
   As the the target population size continues to dwindle in accordance with an exclusion of a respective FY cohort awaiting the Age 25 Milestone Examination within 2 years, the age distribution is skewed to the left, lending an "unnatural" appearance as thyroid cancer is known to increase in adulthood. This is depicted below in a succession of age distribution graphs from the first to fourth rounds taken from the FY2019 report of the Fukushima Health Management Survey accessed on this page

    Graphs on the left show age-at-exposure distribution. The shaded area starts to be seen in the right area of the graph from the third round on. Ordinarily, for thyroid cancer, an upward trend is expected with age, beginning in early 20's. In the age-at-exposure distribution, that corresponds to the shaded area depicting missing data from those transitioning from the regular TUE to the Age 25 Milestone Examination. The age-at-examination distribution graphs on the right show 23 as the maximum age, totally disregarding the missing data.
   One more thing to note: The age-at-examination distribution graphs here might not necessarily show an upward trend with age. This might partially be due to plummeted participation by those ≥ age 18. Participation rates by age groups for the fourth round are 85.4% for ages 6-11, 82.0% for ages 12-17, and 12.4% for ages 18-24.
   As young adults transition to the Age 25 Milestone Screening, participation dips even further; the current participation rate is 8.4%. Thus data gathering becomes more difficult as they leave the regular TUE. Some might undergo cancer screening on their own, totally outside the FHMS system. FMU officials plan to rely on the national cancer registry data mandated in 2016 to fill the void. However, with young adults relocating outside Fukushima Prefecture as life goes on, how exhaustive and reliable the cancer registry data might be for this purpose remains to be seen. 

The first round as of March 31, 2018

The second round as of March 31, 2018

The third round as of June 30, 2019

The fourth round as of June 30, 2019

The fourth round (age-at-exposure) as of June 30, 2020


    
Summary of the results from the previous screening 
     Below is the summary of the previous screening results for the suspected/confirmed thyroid cancer cases. This information, already mentioned above except for the second round, can be difficult to locate in print. In particular, a breakdown of the "A2" assessment is only verbally reported during the Oversight Committee sessions. 

Definition
"A1": no ultrasound findings. 
"A2": ultrasound findings of nodules ≤ 5.0 mm and/or cysts ≤ 20.0 mm. 
"B": ultrasound findings of nodules  5.1 mm and/or cysts  20.1 mm.

   Having previous assessments of "A1" or "A2 cysts" means there were no precancerous lesions during the previous screening, i.e., cancer supposedly appeared since the previous screening. (Note: FMU claims the cancerous lesions were simply "invisible" during the previous screening.)
  • Second round (71 cases): 33 cases with A1, 32 cases with A2 (7 nodules and 25 cysts), 5 cases with B, 1 case previously unexamined
  • Third round (31 cases):  7 cases with A1, 14 cases with A2 (4 nodules and 10 cysts), 7 cases with B, 3 cases previously unexamined
  • Fourth round (27 cases): 5 cases with A1, 16 cases with A2 (4 nodules and 12 cysts), 5 cases with B, 1 case previously unexamined
  • Age 25 Milestone Screening (7 cases): 1 case with A2 (it was never reported if nodule or cyst), 1 case with B, 5 cases previously unexamined
  

Fukushima Thyroid Examination October 2021: 221 Surgically Confirmed as Thyroid Cancer Among 266 Cytology Suspected Cases

Overview      On October 15, 2021,  t he 43rd session of the Oversight Committee  for the Fukushima Health Management Survey (FHMS) convened...