Nakashima Masahiro, Kondo Hisayoshi, Miura Shiro, Soda Midori, Hayashi Tomayoshi, Matsuo Takeshi, Yamashita Shunichi, Sekine Ichiro
Tissue and Histopathology Section, Division of Scientific Data Registry, Atomic Bomb Disease Institute, Nagasaki University Graduate School of Medicine, Nagasaki 851-8523, Japan.
Cancer Sci. 2008 Jan;99(1):87-92. doi: 10.1111/j.1349-7006.2007.00657.x. Epub 2007 Nov 2.
To assess the effects of atomic bomb radiation on the incidence of multiple primary cancers (MPC), we analyzed the association between the incidence of second primary cancers in survivors of the atomic bombing of Nagasaki, and exposure distance. The incidence rate (IR) of a second primary cancer was calculated and stratified by the distance from the hypocenter and age at the time of bombing for the years 1968 through 1999. The IR of the first primary cancer was also calculated and compared with the second primary cancer to determine whether atomic bomb radiation was associated with the multiplicity of tumors. There were 511 confirmed cases of MPC in the 7572 cancer-bearing survivors. The crude IR was 27.6 per 100,000 person-years. The IR of second primaries decreased significantly with increasing distance from the hypocenter: relative risk, 0.89 per 1.0 km; 95% confidence interval, 0.84-0.94. A significant decrease was also noted for those of older ages at the time of the bombing, based on the attained age of the second primary cancer: relative risk, 0.91 per 1 year; 95% confidence interval, 0.90-0.92. These findings suggest that the radiation has affected the incidence of MPC. Furthermore, when compared with the first primary cancer, a stronger distance effect was suggested on the occurrence of a second primary cancer in the survivors. The present study suggests the significance of atomic bomb radiation on MPC in the survivors. These results on the incidence of MPC in the tumor-bearing survivors and its correlations with the atomic bombing of 62 years ago are described for the first time in this report.
为评估原子弹辐射对多发性原发性癌症（MPC）发病率的影响，我们分析了长崎原子弹爆炸幸存者中第二原发性癌症发病率与暴露距离之间的关联。计算了1968年至1999年期间第二原发性癌症的发病率（IR），并按距爆心的距离和爆炸时的年龄进行分层。还计算了第一原发性癌症的发病率，并与第二原发性癌症进行比较，以确定原子弹辐射是否与肿瘤的多发性有关。在7572名患癌幸存者中，有511例确诊为MPC。粗发病率为每10万人年27.6例。第二原发性癌症的发病率随着距爆心距离的增加而显著降低：相对风险为每1.0公里0.89；95%置信区间为0.84 - 0.94。根据第二原发性癌症的达到年龄，在爆炸时年龄较大者中也观察到显著下降：相对风险为每1岁0.91；95%置信区间为0.90 - 0.92。这些发现表明辐射影响了MPC的发病率。此外，与第一原发性癌症相比，幸存者中第二原发性癌症的发生显示出更强的距离效应。本研究表明原子弹辐射对幸存者MPC的重要性。本报告首次描述了这些患癌幸存者中MPC的发病率及其与62年前原子弹爆炸的相关性。
