Project/Area Number |
17591310
|
Research Category |
Grant-in-Aid for Scientific Research (C)
|
Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Radiation science
|
Research Institution | National Institute of Radiological Sciences |
Principal Investigator |
OHNO Tatsuya National Institute of Radiological Sciences, Research Center for Charged Particle Therapy, Senior stuff, 重粒子医科学センター病院, 医長 (10344061)
|
Co-Investigator(Kenkyū-buntansha) |
SHIMADA Yoshiya National Institute of Radiological Sciences, Research Center for Radiation Safety, Proiect leader, 放射線防護研究センター, グループリーダー (10201550)
KAKINUMA Shizuko National Institute of Radiological Sciences, Research Center for Radiation Safety, Senior stuff, 放射線防護研究センター, チームリーダー (20392219)
KATO Shingo National Institute of Radiological Sciences, Research Center for Charged Particle Therapy, Head, 重粒子医科学センター病院, 室長 (00370875)
|
Project Period (FY) |
2005 – 2006
|
Project Status |
Completed (Fiscal Year 2006)
|
Budget Amount *help |
¥3,200,000 (Direct Cost: ¥3,200,000)
Fiscal Year 2006: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 2005: ¥2,100,000 (Direct Cost: ¥2,100,000)
|
Keywords | Malignant neplasm / Radiotherapy / Second cancer |
Research Abstract |
Occurrence of a second cancer is the most serious event among long-term survivors after radiotherapy (RT). The purpose of this study was to evaluate the risk of second cancers after cervical cancer treated with RT. We reviewed 2,167 patients with uterine cervical cancer undergoing RT between 1961 and 1986 at the National Institute of Radiological Sciences. Among them, 1,702 (79%) patients were treated with RT-alone group and 465 (21%) received postoperative RT. Their mean age was 60 years in the RT alone and 49 years in the postoperative RT group. Intracavitary brachytherapy was performed with high-dose rate source (82%) or low-dose rate source (18%) for RT alone. Relative risk (RR) of second cancer was calculated using the Japanese disease expectancy table. In addition, RR of second cancer was calculated by age at RT and the post-RT duration of follow-up. The total number of person-years of follow-up was 25,771, with 60 patients being lost to follow-up. Among 2,167 patients, 1,063 patients (49%) survived more than 10 years. Second cancers developed in 210 patients, which represented a significant increase in risk compared with a comparable normal population (RR = 1.24, 95%CI = 1.08-1.42). RR of developing a second cancer was significantly elevated for patients younger than 60 years at RT (RR = 1.33, 95%CI = 1.10-1.61) and for patients with post-RT follow-up between 5 and 15 years (RR = 1.31, 95%CI = 1.06-1.62). The estimated cumulative probability for development of a second cancer was 6.7% at 10 years, 15.6% at 20 years, and 23.8% at 30 years. Significant increased risk of second cancers was observed among long-term survivors after RT for cervical cancer. RR differed by age at RT and interval of follow-up after RT, helping us to identify a high-risk population for the development of second cancers.
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