National Council on Radiation Protection and Measurements, Bethesda, MA, USA.
Division of Epidemiology, Department of Medicine, Vanderbilt-Ingram Cancer Center, Vanderbilt Epidemiology Center, Vanderbilt University School of Medicine, Nashville, TN, USA.
Int J Radiat Biol. 2022;98(4):769-780. doi: 10.1080/09553002.2018.1547441. Epub 2019 Jan 25.
The study of Japanese atomic bomb survivors, exposed briefly to radiation, finds the risk of radiation-induced lung cancer to be nearly three times greater for women than for men. Because protection standards for astronauts are based on individual lifetime risk projections, this sex-specific difference limits the time women can spend in space. Populations exposed to chronic or fractionated radiation were evaluated to learn whether similar differences exist when exposures occur gradually over years.
Five occupational cohorts within the Million Person Study of Low-Dose Health Effects (MPS) and a Canadian Fluoroscopy Cohort Study (CFCS) of tuberculosis patients who underwent frequent chest fluoroscopic examinations are evaluated. Included are male and female workers at the Mound nuclear facility, nuclear power plants (NPP), and industrial radiographers (IR). Workers at the Mallinckrodt Chemical Works and military participants at aboveground nuclear weapons tests provide information on the risk among males. Cox proportional hazards and Poisson regression models were used to estimate sex-specific radiation risks for lung cancer and to compare any differences.
Overall, 15,065 lung cancers occurred among the 443,684 subjects studied: 50,111 women and 395,573 men. The mean cumulative dose to the lung was 166.3 mGy (range 6 to 1,055 mGy) with the highest among the TB-fluoroscopy patients (mean 1,055 mGy). Mean lung dose for women in the worker cohorts was generally 4 times lower than for men. Of the 12 estimates of radiation-related risk, only one, for male IRs, showed a significant elevation (ERR 0.09; 95% CI 0.02-0.16, at 100 mGy). In contrast, the dose response for male NPP workers was negative (ERR -0.05; 95% CI -0.10, 0.01, at 100 mGy). Combined, these two cohorts provided little evidence for a radiation effect among males (ERR 0.01; 95% CI -0.04, 0.06, at 100 mGy). There was no significant dose-response among females within any cohort. There was no difference in the sex-specific estimates of lung cancer risk.
There was little evidence that chronic or fractionated exposures increased the risk of lung cancer. There were no differences in the risks of lung cancer between men and women. However, the sex-specific analyses are limited because of small numbers of women and relatively low doses. A more definitive study is ongoing of medical radiation workers which include 85,000 women and 85,000 men (overall mean dose 82 mGy, max 1,140 mGy). Additional understanding will come from the ongoing follow-up of the CFCS.
对曾短暂接触过辐射的日本原子弹幸存者进行的研究发现，女性因辐射而患肺癌的风险比男性高近 3 倍。由于宇航员的防护标准是基于个体终身风险预测，因此这种性别特异性差异限制了女性在太空中的时间。本研究评估了人群在慢性或分次辐射暴露下是否存在类似的差异，因为这些暴露是在数年时间内逐渐发生的。
本研究评估了百万人群低剂量健康效应研究（MPS）中的五个职业队列和加拿大透视检查结核病患者队列研究（CFCS）。队列中包括莫恩核设施、核电厂（NPP）和工业放射技师（IR）的男性和女性工作人员。马林斯克罗特化学厂的工人和参加过地面核武器试验的军人提供了男性风险的信息。Cox 比例风险和泊松回归模型用于估计肺癌的性别特异性辐射风险，并比较任何差异。
在研究的 443684 名受试者中，共有 15065 例肺癌发生：50111 名女性和 395573 名男性。肺的累积剂量中位数为 166.3mGy（范围为 6 至 1055mGy），最高的是 TB-透视检查患者（中位数为 1055mGy）。女性工人队列的平均肺剂量通常比男性低 4 倍。在 12 项辐射相关风险估计中，只有一项男性 IR 的结果显示出显著升高（ERR 0.09；95%CI 0.02-0.16，在 100mGy 时）。相比之下，男性 NPP 工人的剂量反应为负（ERR-0.05；95%CI-0.10，0.01，在 100mGy 时）。这两个队列联合起来，几乎没有提供男性辐射效应的证据（ERR 0.01；95%CI-0.04，0.06，在 100mGy 时）。在任何队列中，女性的剂量反应均无显著差异。男女肺癌风险无差异。然而，由于女性人数较少且相对剂量较低，因此对性别特异性风险的分析受到限制。一项针对医疗放射工作人员的更明确的研究正在进行中，其中包括 85000 名女性和 85000 名男性（平均总剂量为 82mGy，最高为 1140mGy）。CFCS 的持续随访将提供更多的了解。
