A Comparison of Thyroid Cancer Latency Periods given by Fukushima Medical University and Other Qualified Authorities
Since 2011 Fukushima Medical University staff engaged in the Thyroid health survey of Fukushima children cite sources based on Chernobyl data which the staff claim supports:
1. A long 4-5 year latent period for childhood thyroid cancer.
2. A slow progression of the disease once disease has commenced.
Staff of the Fukushima Medical University, including Dr. Yamashita and Dr. Suzuki, have clearly informed the media of the FMU position in these matters. For example:
“Researchers at Fukushima Medical University, which has been taking the leading role in the study, have said they do not believe the most recent cases are related to the nuclear crisis. They point out that thyroid cancer cases were not found among children hit by the 1986 Chernobyl nuclear accident until four to five years later.” end quote. (Source: Japan Times. Kyodo. 06/05/2013 http://www.japantimes.co.jp/news/2013/06/05/national/fukushima-survey-lists-12-conﬁrmed-15-suspected-thyroid-cancercases/#.UbCB7Ovrk7A
“…experts at Fukushima Medical University said that it is too early to link the cancer cases to the nuclear disaster. They said the 1986 Chernobyl accident showed that it takes at least four to ﬁve years before thyroid cancer is detected.” end quote.
Source: Thyroid cancer hits Fukushima5 Jun 2013, 12:57 pm – Source: AAP, SBS TV Australia, http://www.sbs.com.au/news/article /1774837/Thyroid-cancer-hits-Fukushima (http://www.sbs.com.au/news/article/1774837 /Thyroid-cancer-hits-Fukushima)
Other qualified sources actually confirm that latent periods in early onset cases of the disease post Chernobyl were very short, and these sources report that disease progression in the early onset cases post Chernobyl was rapid. The authors of these reports include Dr. S. Yamashita, formerly head of the Fukushima Medical University Fukushima Thyroid Health Survey. These other international sources are described in brief below:
Brief Quotations from some Sources which Contradict Fukushima Medical University regarding Latency and speed of disease progression in Thyroid Cancer:
Qualified Papers which appear to contradict the ascertains Fukushima Medical University and its staff in regard to both the latency period for childhood thyroid cancer and speed of progression of the disease include the following authors and organizations:
Dr. S. Yamashita, et. al., First Department of Internal Medicine, Nagasaki University School of Medicine, Japan. Endocr J. 1998 Apr;45(2):203-9. 1998. “Childhood thyroid cancer: comparison of Japan and Belarus.” Full text download link: https://www.jstage.jst.go.jp/article/endocrj1993/45/2/45_2_203/_pdf
“tumors arising in the Chernobyl population began developing with surprising rapidity and short latency.”
Mikhail V. MALKO, Joint Institute of Power and Nuclear Research, National Academy of Sciences of Belarus Krasin Str. 99, Minsk, Sosny, 220109, Republic of Belarus. 1998. “Chernobyl Radiation-induced Thyroid Cancers in Belarus”. Download full text at http://www.rri.kyoto-u.ac.jp/NSRG/reports/kr79/kr79pdf/Malko2.pdf
“absence of marked latency period is another feature of radiation-induced thyroid cancers caused in Belarus as a result of this accident.”
US CDC, John Howard, M.D., Administrator World Trade Center Health Program, 9.11 Monitoring and Treatment, Revision: May 1,2013. “Minimum Latency & Types or Categories of Cancer”. Link: http://www.cdc.gov/wtc/pdfs/wtchpminlatcancer2013-05-01.pdf
“2.5 years, based on low estimates used for lifetime risk modeling of low-level ionizing radiation studies”
Shoichi Kikuchi, MD, PhD, et.al., Department of Surgery, UCSF Affiliated Hospitals, San Francisco, California. 2004. “Latency Period of Thyroid Neoplasia After Radiation Exposure”. Ann Surg. Apr 2004; 239(4): 536–543.
Download link: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1356259/
“The shortest latency period for both benign and malignant tumors was 1 year as occurred in 3 patients, whereas the longest time was 69 and 58 years, respectively.”
The statements reported in the mass media and attributed to Dr. Yamashita, Dr. Suzuki and staff of the Fukushima Medical University claim that scientific data gathered in the wake of the Chernobyl nuclear shows that no childhood thyroid cancer due to nuclear arose in Chernobyl affected areas until the passage of “four or five years”. Also, the claim is made by Fukushima Medical University that the progression/development/growth of childhood thyroid cancer as induced in Chernobyl affected areas was “slow”.
As a layperson I sought to find qualified documents to confirm the statements made by Yamashita, Suzuki and Fukushima Medical University.
What I found are papers which observe that the latent period of childhood thyroid cancer, including radiation induced thyroid cancer, is in fact “rapid”, “very short”, “1 year”, “2.5 years”. I further found that the qualified apart from Fukushima Medical University found that the progression of the disease was “very rapid”.
Among the sources which confirm this information, in direct contradiction to Fukushima Medical University’s statements, was Dr. S. Yamashita, 1998. The same doctor who, on behalf of FMU, in 2011 stated that “thyroid cancer cases were not found among children hit by the 1986 Chernobyl nuclear accident until four to five years later.”
As the experts at Fukushima Medical University must surely know, significant bodies of evidence presented as qualified papers pre dating March 2011 show that the evidence of Chernobyl and other radiation exposure experiences have been shown to produce :
1. A very short latency period and
2. A rapid progression of disease
in regard to childhood thyroid cancer.
I challenge the staff of Fukushima Medical University to explain why:
1. Dr. Yamashita contradicts himself post Fukushima compared to his 1998 findings
2. FMU continues with a minority position regarding latency and disease progression rates in spite of numerous international papers which contradict the FMU position. ‘
The differences between the shortest latent period, the average latent period and the median latent period need to be understood by the public. Fukushima Medical University appear to be confused between the term “shortest” and “median”.
The most common (ie the median) latent period is not the only relevant latent. Some children in Belarus suffered the onset of disease and its rapid progression, directly as a result of Chernobyl, with very little latent period at all.
Just ask Dr. Yamashita.
I have a final question. Given that world authorities disagree with the Fukushima Medical University’s definition of the shortest latent period and speed of progression of the disease:
Are the children of Fukushima who have suffered the onset of thyroid cancer since March 2011 being denied justice by FMU and other Japanese authorities?