Effect of age and pregnancy history on breast cancer risk: a study relevant to female astronauts

2017 Fiscal Year Final Research Report

• Project/Area Number: 26506027
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: 宇宙生命学
• Research Institution: National Institutes for Quantum and Radiological Science and Technology
• Principal Investigator: Nishimura Mayumi 国立研究開発法人量子科学技術研究開発機構, 放射線医学総合研究所 放射線影響研究部, 専門業務員(任常) (70218204)
• Co-Investigator(Renkei-kenkyūsha): Shimada Yoshiya 国立研究開発法人量子科学技術研究開発機構, 理事 (10201550) ; Imaoka Tatsuhiko 国立研究開発法人量子科学技術研究開発機構, 放射線医学総合研究所 放射線影響研究部, チームリーダー (40356134) ; Kakinuma Shizuko 国立研究開発法人量子科学技術研究開発機構, 放射線医学総合研究所 放射線影響研究部, 部長 (20392219) ; Daino Kazuhiro 国立研究開発法人量子科学技術研究開発機構, 放射線医学総合研究所 放射線影響研究部, 主任研究員 (90543299)
• Project Period (FY): 2014-04-01 – 2018-03-31
• Keywords: 乳がん / 発がんリスク / 妊娠・出産 / 中性子線 / 女性宇宙飛行士

Outline of Final Research Achievements

Epidemiological studies on both atomic-bomb survivors and patients with radiotherapy have shown that breast tissue is one of the organs with high risk of radiogenic cancer. Astronauts working at the International Space Station need to consider the exposure to neutron beams, because it has high biological effects. Although it is generally known that the risk of sporadic breast cancer depends on reproductive history, little is known about the effect of parity on radiogenic breast cancer. In this study, we found, using rat model, that whereas the risk of spontaneous mammary cancer has been only slightly, but not significantly, decreased by parity,the risk of breast cancer induced by radiation, either γ-ray (4 Gy) or neutrons (0.05 - 0.5 Gy), was almost completely suppressed.

Free Research Field

放射線生物