著者
YUTAKA SHIRAHIGE MASAHIRO ITO KIYOTO ASHIZAWA TOMOKO MOTOMURA NAOKATA YOKOYAMA HIROYUKI NAMBA SHUJI FUKATA TAMOTSU YOKOZAWA NAOFUMI ISHIKAWA TAKASHI MIMURA SHUNICHI YAMASHITA ICHIRO SEKINE KANJI KUMA KUNIHIKO ITO SHIGENOBU NAGATAKI
出版者
The Japan Endocrine Society
雑誌
Endocrine Journal (ISSN:09188959)
巻号頁・発行日
vol.45, no.2, pp.203-209, 1998 (Released:2006-11-25)
参考文献数
30
被引用文献数
16 19

The high incidence of childhood thyroid cancer in Belarus is suspected to be due to radiation exposure after the Chernobyl reactor accident. To clarify the clinical and histological characteristics of childhood thyroid cancer in Belarus, we therefore compared these patients to a radiation non-exposed control series in Japan. In Belarus, 26 thyroid cancers in subjects aged 15 or younger were diagnosed among 25, 000 screened between 1991 and 1995 by Chernobyl-Sasakawa Health and Medical Cooperation Project. The clinical and morphologic features of these 26 cases were compared to 37 childhood thyroid cancers in Japan diagnosed between 1962 and 1995. The age distribution at operation in Belarus showed a peak at 10 years old, with a subsequent fall in numbers. In contrast, the age distribution at operation in Japan showed a smooth increase between the ages of 8 and 14. The mean tumor diameter was smaller in Belarus than that in Japan (1.4±0.7 vs. 4.1±1.7cm, P<0.001). The sex ratio, regional lymph node metastasis, extension to surrounding tissues or lung metastasis did not differ significantly. Histologically, all cases in Belarus were papillary and in Japan 33 cases were papillary and 4 cases were follicular carcinomas. Among papillary carcinomas, the frequency of a solid growth pattern, a criteria for classifying a tumor as poorly differentiated, was higher in Belarus than that in Japan (61.5 vs.18.2%, P<0.001). The difference between the features of childhood thyroid cancer in Japan and Belarus may be due to the difference in the process of carcinogenesis, but more direct evidence and further analysis by molecular epidemiology are needed in Belarussian cases.
著者
Shigenobu NAGATAKI
出版者
Japan Health Physics Society
雑誌
保健物理 (ISSN:03676110)
巻号頁・発行日
vol.45, no.4, pp.370-378, 2010 (Released:2011-07-12)
参考文献数
12
被引用文献数
4 7

The latest knowledge encompass findings presented both in individual scientific publications and in internationally accepted reports. This review summarizes the latest knowledge on radiobiological effects on the latter level, using studies of atomic bomb survivors and victims of Chernobyl nuclear power plant accident. First of all, it is important to note that while examining individual patient, it is impossible to distinguish a radiation-induced cancer patient and non-radiation-induced cancer patient even when using state-of-the-art techniques. Therefore, investigation of radiation effects on humans, especially late health effects has been based on the epidemiological and statistical methods. Based on studies on atomic bomb survivors, it is well accepted that there is a linear increase in the risk of cancer with the increase of radiation dose. However, the existence of a threshold is a controversial issue, and health effects with regards to non-cancer diseases are not yet accepted by international authorities. Childhood thyroid cancer has increased after the Chernobyl accident and more than several thousands children are affected by it. However, there is no proof that any disease, with the exception of thyroid cancer and acute radiation effects, has increased after the Chernobyl accident. Finally, it should be mentioned that providing scientific explanation of the results to general public is an honorable duty of concerned scientists.