JCJTC's view on a paper entitled “Definition of overdiagnosis, and how to use oversurgery/overtreatment: differences of the standpoints between pathologists and epidermiologists”, published in the Journal of Japan Association of Endocrine Surgery
The following Japanese paper was published as a special article in the Journal of Japan Association of Endocrine Surgery.＜Link＞
Definition of overdiagnosis, and how to use oversurgery/overtreatment: differences of the standpoints between pathologists and epidermiologists.
Authors:
Atsuhiko Sakamoto*, Mitsuyoshi Hirokawa**, Masahiro Ito***, Hiroshi Naganuma****, Osamu Suzuki*****, Yuko Hashimoto***** and Shinichi Suzuki*****
Department of Pathology and Laboratory Medicine, Omori Red Cross Hospital*, Department of Diagnostic Pathology and Cytology, Kuma Hospital**, Department of Pathology, NHO Nagasaki Medical Center***, Department of Pathology, Sendai Red Cross Hospital****, Department of Diagnostic Pathology, School of Medicine, Fukushima Medical University*****, Department of Thyroid and Endocrinology, School of Medicine, Fukushima Medical University****** Atsuhiko Sakamoto*, Mitsuyoshi Hirokawa**, Masahiro Ito***, Hiroshi Naganuma****, Osamu Suzuki*****, Yuko Hashimoto***** and Shinichi Suzuki*****
Abstract:
Six of the authors from the first author were the members of the pathological diagnosis consensus board of the Fukushima Prefectural Health Monitoring Survey (FHMS). After the Fukushima Daiichi Nuclear Power Plant Accident (March 2011), Arbitrary pediatric thyroid ultrasonography is being performed based on the lessons learned from the frequent occurrence of pediatric thyroid cancer after the Chernobyl accident. When the diagnosis is malignant or suspected malignant, surgery is recommended as needed. Regarding this survey, there are voices that the setting of the survey target is inappropriate and there is a possibility that unnecessary tests are being conducted. They criticize the FHMS for causing overdiagnosis. By pathologists and cytopathologists, the term overdiagnosis is used only to indicate a pathological misdiagnosis such as diagnosing a benign lesion as cancer. Various misunderstandings have arisen because the terms and definitions are used in confusing ways. The purpose of this paper is not to discuss the pros and cons of the FHMS. Our intention is to show that both pathologists and epidemiologists have different positions regarding the definition and usage of overdiagnosis and over-surgery/over-treatment, and discuss solutions to today's confusion.
In the body of their paper, the authors claimed as follows. Their previous reports claimed that there was no overdiagnosed case in Fukushima, but it was only in the pathological sense. Thus, it is not appropriate that some researchers criticized our opinion because they believe that overdiagnosis should have occurred in the FHMS in the epidemiological sense. They should call such an event “overtesting”, but not overdiagnosis.
The following is the view of the JCJTC core members on this paper.
1) It is true that some pathologists use the term "overdiagnosis" for pathological misdiagnosis, that is, benign tumors that can be cured by surgery or tumors that are unlikely to harm the patient are diagnosed as high-grade cancers that can lead to recurrence or death.
2) However, at present, the majority of international experts, including pathologists, use the term overdiagnosis as the epidemiological meaning advocated by Welch HG (diagnosis of a lesion that does not harm the patient for life). It is unlikely that the definition of overdiagnosis will be changed to the meaning of "pathological misdiagnosis" in the future by the assertion of this paper.
3) Therefore, if one uses the term overdiagnosis for thyroid cancer in Fukushima to mean "pathological misdiagnosis," he/she should clearly define that he/she uses the term overdiagnosis with a pathological meaning.
4) Overdiagnosis in the epidemiological sense occurs in every test, and pathological diagnosis is no exception. If experts disseminate information that overdiagnosis (in the pathological sense) has not occurred in Fukushima, the general public may have a misleading perception of some harmful effects of the thyroid examination. Even if one wishes to emphasize that the pathological diagnoses were made correctly in Fukushima and uses the term overdiagnosis only to mean "pathological misdiagnosis," one should add the comment that overdiagnosis in an epidemiological sense is prominent in Fukushima.