STUDIES OF RADIATION-INDUCED CANCER

受辐射的人群在医疗、职业、 正在对环境或军事情况进行研究，以量化 并了解更多关于致癌机制的知识。什么时候 可能的话，实验室研究被纳入流行病学 调查。工作人员在为政府提供建议的委员会任职 和国际机构。 最近的研究结果表明：(1)全身化疗联合 放射治疗大大增加了接受治疗的妇女患白血病的风险 乳腺癌；(2)乳腺癌的放射治疗也会增加风险。 对侧乳癌的风险，但仅限于45岁以下的女性 当接受治疗时；(3)消化性溃疡的放射治疗增加了 胃癌，手术治疗后进一步增加；(4) 儿童视网膜母细胞瘤的成年幸存者继续处于高危状态 导致第二种癌症的发生；放射治疗增强了基因 对骨肉瘤的易感性；(5)高剂量率下的高剂量是 在接受治疗的妇女中，低剂量率下的白血病比低剂量低 子宫内膜癌；(6)诊断剂量的放射性碘 不会增加患甲状腺癌的风险，这表明 剂量降低风险；(7)双胞胎患上疾病的风险明显较低 儿童癌症比独生子女更多，尽管暴露频率更高 对产前x光的危害；(8)室内氡暴露的危害较小 比之前认为的要好；(9)地下人群患肺癌的风险 矿工随氡累积暴露量增加而减少 达到的年龄和暴露后的时间；(10)在原子弹幸存者中， 首次怀孕年龄对辐射诱发乳房的保护作用 癌症；(11)辐射诱发的甲状腺癌在这些人中不明显 20岁以后暴露；(12)非黑色素瘤皮肤癌与肝癌相关 第一次接受原子弹照射；(13)在两个原子弹幸存者中 和铀矿工，辐射诱发的肺癌往往是 小细胞亚型。

Populations irradiated in the course of medical, occupational, environmental, or military circumstances are being studied to quantify cancer risks and to learn more about carcinogenic mechanisms. When possible, laboratory studies are incorporated into epidemiologic investigations. Staff members serve on committees advising the government and international agencies. Recent findings indicate that (1) systemic chemotherapy combined with radiotherapy greatly enhances the risk of leukemia in women treated for breast cancer; (2) radiotherapy for breast cancer also increases the risk of cancer in the opposite breast, but only among women under the age of 45 when treated; (3) radiotherapy for peptic ulcer increases the risk of stomach cancer, which is further increased after surgical treatment; (4) adult survivors of childhood retinoblastoma continue to be at high risk for developing a second cancer; radiotherapy enhances the genetic susceptibility for osteosarcoma; (5) high doses at high dose rates are less leukemogenic than low doses at low dose rates among women treated for cancer of the endometrium; (6) diagnostic doses of radioactive iodine did not increase the risk of thyroid cancer, suggesting that protraction of dose reduces risk; (7) twins are at significantly low risk of developing childhood cancer than single births despite being exposed more frequently to prenatal x-rays; (8) indoor exposure to radon appears less hazardous than previously thought; (9) the risk of lung cancer among underground miners increases with cumulative exposure to radon and decreases with attained age and time since exposure; (10) among A-bomb survivors, early age at first time pregnancy protected against radiation-induced breast cancer; (11) radiation-induced thyroid cancer is not apparent among those exposed after age 20; (12) non-melanoma skin and liver cancers were linked to A-bomb irradiation for the first time; (13) in both A-bomb survivors and uranium miners, radiation-induced lung cancers tend to be of the small-cell subtype.