Preston Dale L, Cullings Harry, Suyama Akihiko, Funamoto Sachiyo, Nishi Nobuo, Soda Midori, Mabuchi Kiyohiko, Kodama Kazunori, Kasagi Fumiyoshi, Shore Roy E
Hirosoft International Corporation, 1335 H St, Eureka, CA 95501-2331, USA.
J Natl Cancer Inst. 2008 Mar 19;100(6):428-36. doi: 10.1093/jnci/djn045. Epub 2008 Mar 11.
In utero exposure to radiation is known to increase risks of childhood cancers, and childhood exposure is associated with increased risks of adult-onset cancers. However, little is known about whether in utero exposure to radiation increases risks of adult-onset cancers.
Solid cancer incidence rates were examined among survivors of the atomic bombings of Hiroshima and Nagasaki who were in utero (n = 2452) or younger than 6 years (n = 15388) at the time of the bombings. Poisson regression was used to estimate and compare the levels and temporal patterns of the radiation-associated excess risks of first primary solid cancers among these survivors at ages 12-55. All statistical tests were two-sided.
There were 94 eligible cancers in the in utero group and 649 in the early childhood group. The excess relative risk (ERR) increased with dose for both in utero (age 50, ERR = 1.0 per Sv, 95% confidence interval [CI] = 0.2 to 2.3 per Sv) and early childhood (age 50, ERR = 1.7 per Sv, 95% CI = 1.1 to 2.5 Sv) exposures. The ERR declined (P = .046) with increasing attained age in the combined cohort. Excess absolute rates (EARs) increased markedly with attained age among those exposed in early childhood but exhibited little change in the in utero group. At age 50, the estimated EARs per 10,000 person-years per Sv were 6.8 (95% CI = <0 to 49) for those exposed in utero and 56 (95% CI = 36 to 79) for those exposed as young children.
Both the in utero and early childhood groups exhibited statistically significant dose-related increases in incidence rates of solid cancers. The apparent difference in EARs between the two groups suggests that lifetime risks following in utero exposure may be considerably lower than for early childhood exposure, but further follow-up is needed.
已知子宫内暴露于辐射会增加儿童患癌风险，而儿童期暴露与成年后患癌风险增加有关。然而，关于子宫内暴露于辐射是否会增加成年后患癌风险，人们知之甚少。
对广岛和长崎原子弹爆炸幸存者中在子宫内（n = 2452）或爆炸时年龄小于6岁（n = 15388）的人群的实体癌发病率进行了检查。使用泊松回归来估计和比较这些幸存者在12 - 55岁时首次原发性实体癌的辐射相关超额风险水平和时间模式。所有统计检验均为双侧检验。
子宫内暴露组有94例符合条件的癌症病例，幼儿期暴露组有649例。子宫内暴露（50岁时，超额相对风险[ERR]=每西弗1.0，95%置信区间[CI]=每西弗0.2至2.3）和幼儿期暴露（50岁时，ERR =每西弗1.7，95% CI =每西弗1.1至2.5）的超额相对风险均随剂量增加。在合并队列中，超额相对风险随达到的年龄增加而下降（P = 0.046）。幼儿期暴露者的超额绝对发病率（EARs）随达到的年龄显著增加，但子宫内暴露组变化不大。在50岁时，每西弗每10000人年的估计EARs，子宫内暴露者为6.8（95% CI = <0至49），幼儿期暴露者为56（95% CI = 36至79）。
子宫内暴露组和幼儿期暴露组的实体癌发病率均出现了与剂量相关的显著增加。两组之间EARs的明显差异表明，子宫内暴露后的终生风险可能远低于幼儿期暴露，但需要进一步随访。
