Study of the late effect on occurrence of thyroid and lung cancers of low dose irradiation from the atomic bomb tests in the Marshall Islands

2005 Fiscal Year Final Research Report Summary

• Project/Area Number: 15406023
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 海外学術
• Research Field: Hygiene
• Research Institution: Tohoku University
• Principal Investigator: FUJIMORI Keisei Tohoku University, Graduate School of Medicine, Associate Professor, 大学院・医学系研究科, 助教授 (50238622)
• Co-Investigator(Kenkyū-buntansha): OHCHI Noriaki Tohoku University, Graduate School of Medicine, Professor, 大学院・医学系研究科, 教授 (90203710) ; SATOMI Susumu Tohoku University, University Hospital, Professor, 大学病院, 教授 (00154120) ; DOI Hideyuki Tohoku University, University Hospital, Associate Professor, 大学病院, 助教授 (90188839) ; MIYATA Goh Tohoku University, University Hospital, Lecturer, 大学病院, 講師 (60282076) ; SEKIGUCHI Satoshi Tohoku University, Graduate School of Medicine, Research Associate, 大学院・医学系研究科, 助手 (20312580)
• Project Period (FY): 2003 – 2005
• Keywords: late effect of irradiation / Bravo test / thyroid cancer / lung cancer / breast cancer / Marshall Islands / DM / chronic thyroiditis

Research Abstract

We have done thyroid examinations (interviews on residency and smoking history, palpation, ultra-sono-tomography, blood sampling for thyroid function and auto-antibody ; AB : TGAb, TPOAb) for 1386 Marshalleses (mean age 50.9+/-12.34yo) from Feb 20 to Mar 22, 2006, at Majuro. The 386 people have belonged to the BRAVO cohort. The cohort was consisted of the Marshalleses born before BRAVO test on Mar 1,1954 at Bikini and had had our thyroid examination from 1993 to 1997 at Majuro and other atolls. It had had 3714. The 1055 of the cohort were under 5 yo at the BRAVO test. The 322 of the 1055 had thyroid re-examination at this time. We have found 4 strongly thyroid cancer suspected cases among the 322. The positive rate of Abs by CLEIA were around 20%. By palpation typical chronic thyroiditis was very rare, however, autoantibody positive ratio might not be low.
We have reviewed the death certificates of the RMI. Till Dec 31, 2003 we have found 642 deaths of the BRAVO cohort. The mean death age was 63.9 yo. The 107 death causes were cancer. The most frequent was lung cancer and its number was 32 (23 men and 9 women). A comment of heavy smoker was seen in almost all men death certificates. The breast cancer death and the thyroid cancer death were 6 and two respectively. The cancers of digestive organs and uterus were popular. The other frequent death causes out of cancers were hepatic, respiratory, heart and renal failures, strokes, DM and sepsis.
We have established the data base of the BRAVO cohort on death causes and thyroid cancers. The exact incidence of the thyroid cancer can be estimated on the data base and might be concluded the late effects of the irradiation among the Marshalleses from the dosimetry of each people.