Iinuma T, Tateno Y
Division of Clinical Research, National Institute of Radiological Sciences.
Nihon Igaku Hoshasen Gakkai Zasshi. 1990 Feb 25;50(2):101-6. doi: 10.1093/oxfordjournals.rpd.a031801.
The mass screening of lung cancer has been started with financial support of the Japanese Government from 1987. It should be emphasized, however, that mass screening programs of any kind have to be evaluated by means of benefit-risk analysis and cost-effectiveness analysis. This is the first report on the benefit-risk analysis for mass screening program of lung cancer in Japan. The benefit of the lung cancer mass screening is defined as a net elongation of average life expectancy due to early detection of the cancer. It is calculated as a function of age and sex. While, the risk of the screening program is defined as a net shortage of average life expectancy due to radiation carcinogenesis of leukemia and lung cancer. In the case of radiation carcinogenesis, latent time and plateau period are considered in the calculation of the risk. Since the benefit increases with age and the risk decreases with age for both sexes, one can obtain a certain age at which the benefit and the risk cross. Assuming dose equivalent of lung of 1 mSv and risk coefficient of 15.1 X 10(-3) Sv-1, the crossing ages of men and women are about 42 y.o. and 47 y.o. respectively. We consider that these ages are rather high when chest radiograph is to be used as a screening test. It is recommended that the dose equivalent of lung should be lowered to 0.1 mSv if the mass screening of lung cancer is to be performed.
自1987年起，在日本政府的财政支持下，肺癌群体筛查工作已经启动。然而，应当强调的是，任何类型的群体筛查项目都必须通过利弊分析和成本效益分析来进行评估。这是日本首份关于肺癌群体筛查项目利弊分析的报告。肺癌群体筛查的益处被定义为因癌症早期发现而导致的平均预期寿命的净延长。它是根据年龄和性别来计算的。同时，筛查项目的风险被定义为因白血病和肺癌的辐射致癌作用导致的平均预期寿命的净缩短。在辐射致癌的情况下，计算风险时会考虑潜伏期和平稳期。由于男女的益处都随年龄增长而增加，风险随年龄增长而降低，所以可以得出益处和风险交叉的某个年龄。假设肺部剂量当量为1毫希沃特，风险系数为15.1×10⁻³希沃特⁻¹，男性和女性的交叉年龄分别约为42岁和47岁。我们认为，当使用胸部X光片作为筛查测试时，这些年龄相当高。如果要进行肺癌群体筛查，建议将肺部剂量当量降低到0.1毫希沃特。
