The study addresses vulnerable populations by initially focusing on youths that were in the vicinity of the Fukushima disaster at the time of the event. These subjects are vulnerable due to their proximity to the nuclear disaster, but also due to their age and the fact that they are still developing, causing them to be at more risk.
Technical professionals can use this data to perhaps launch other studies to analyze the true effects of the disaster in Japan on thyroid cancer rates in adjacent areas. This study and data finings from this can be used to show the need for further studies on the matter in order to determine the correlation between cancer rates and the disaster. The study overall shows that there were high screening rates for thyroid cancer after the disaster, yet attributes it to the possibility of over diagnosis. This study can open the doors for numerous more studies on this matter. This study can also be used down the road as a reference for anyone who wishes to study the degree of fallout and cancer rates caused by a nuclear disaster. Methods used in this study can be modeled down the road for other disasters, with adjustments accounting for the possibility of over diagnosis.
This article has been cited and referred to in an study published in the Journal of Radiological Protection. It is entitled 'Chernobyl and Fukushima-where are we now?' Written by Richard Wakeford.
http://iopscience.iop.org/article/10.1088/0952-4746/36/2/E1
This paper is also referenced by 9 other papers and is published in numerous oncology related journals.
After the Fukushima disaster, thyroid examinations were performed on residents less than 18 years of age. The first three years post disaster are noted as the "Initial phase" and act as a control. Of those tested, 113 cases were suspected of or found to have thyroid malignancies, 99 of those underwent surgery. After this, the goal became to compare and observe prevalence of thyroid cancer in this initial screen program with historical controls based off if there was a nuclear disaster or not.
For this study, the observed/expected ratio was calculated for residents less than 20 years old. Observed prevalence of cancer was calculated using numbers found in the initial thyroid screening program mentioned above. Expected prevalence was then calculated by using a life-table method utilizing national estimates of thyroid cancer incidences before the disaster. The population of Fukushima was taken into account. A 5 year cumulative risk of thyroid cancer incidences was calculated for the year of 2010. This 5 year risk was then converted to a 1 year cumulative risk using a method called spline smoothing. Then the age-specific prevalence of thyroid cancer was estimated by multiplying the 0 year old population by the age specific risk in 2010.
I have done research involving cancer rates and their correlation with power plants (in my case Indian Point.) Doing that research caused me to read hundreds of studies similar to this one where estimates are made using calculations based off cancer rates before the incident and then taking them and putting them into context of a post disaster area. I wouldn't quite say that this method is new or inventive but it follows similar methodology to other studies of this same caliber, yet there are aspects that make it more unique such as converting the 5 year to 1 year cumulative risk using a spline smoothing method.
This study was written by Kota Katanoda et al and recently published in 2016. The article is published by JJCO (Japanese journal of Clinical Oncology.) This journal publishes many works involving cancer studies and epidemiological studies analyzing the distribution of cancers. This journal focuses on oncology and the medical aspects of causes and effects based off radiation exposure, surgeries mainly focused on effects seen on Asian countries and citizens. The journal focuses on all types of cancers and publishes meta-analyses, as well as systematic reviews of risks that patients face post or pre surgery in terms of cancer, as well as possible reactions to disasters or radiation exposure. This journal has numerous publications as well as has ties to the Oxford Journals, it is regarded as a dependable and noteworthy journal for clinical oncology by peers. It is edited by Tadao Kakizoe and was established in 1971.
There is a separate section of the study that cites where the funding for the study came from. The study was supported by Grants-in -aid for the Cancer Control Policy from the Ministry of Health, labour and Welfare, Japan. The study also notes that the funder didn't play a role in the conduct of the study .
The objective of this study was to evaluate whether the amount of cases of thyroid cancer post Fukushima disaster reported were overestimated. The study focused on noting and analyzing if the high reported prevalence of thyroid cancer cases in the areas surrounding the disaster were over diagnosed. Factors such as O/E ratio, utilizing the life table method, as well as national estimates were used in order to determine whether the reported amount of thyroid cancer cases of those aged 20 years in the area were accurate or too exaggerated and ultimately over diagnosed.