Okamoto N
Department of Epidemiology, Kanagawa Cancer Center, Yokohama, Japan.
Cancer. 2000 Dec 1;89(11 Suppl):2489-93. doi: 10.1002/1097-0142(20001201)89:11+<2489::aid-cncr29>3.3.co;2-5.
Because the mortality rate from lung cancer is increasing sharply in Japan, lung cancer screening is being performed actively to assure early diagnosis and early treatment. However, its effectiveness is not clear, because it is extremely difficult to diagnose early microcarcinoma of the lungs (< 1 cm in greatest dimension) with the indirect X-rays that are used in mass screening. Therefore, the authors compared differences in the study population by gender and by age and economic class with the present method for mass screening of lung cancer as well as with computed tomography (CT) screening from the standpoint of cost-effectiveness.
The cost-effectiveness of lung cancer screening was analyzed using the deterministic mathematical model developed by T. Iinuma. The total cost for one life saved (Y/N) and the total cost for the mean life expectancy of a patient saved (Y/NT) were compared for each three cases: mass screening of the type used in 1983, mass screening of the present type, and mass screening using CT in 1993.
For the present mass screening method, the results show that costs are reduced when patients are males age - 55 years and females age > or = 65 years. There was almost no difference between 1983 and 1993, and the percentage increased slightly with the introduction of CT. The cost-effectiveness was observed using two values, Y/N and Y/NT. The cost of screening in 1993 for females age < or = 50 years was lower than that in 1983, but there was no major difference in males from the other age groups. The Y/NT value became even lower when CT was introduced.
The results show that the present method used in lung cancer screening is cheaper, but its effectiveness is also low; and, although the cost of screening by CT is higher than that of the present screening method, it is much more effective. Lung cancer screening by CT should become the most appropriate screening method with respect to cost-effectiveness.
由于日本肺癌死亡率急剧上升，肺癌筛查正在积极开展以确保早期诊断和早期治疗。然而，其有效性尚不清楚，因为在大规模筛查中使用的间接X线极难诊断早期肺微癌（最大直径<1cm）。因此，作者从成本效益的角度比较了目前肺癌大规模筛查方法以及计算机断层扫描（CT）筛查在不同性别、年龄和经济阶层研究人群中的差异。
使用T. Iinuma开发的确定性数学模型分析肺癌筛查的成本效益。比较了三种情况中每挽救一条生命的总成本（Y/N）以及每挽救一名患者平均预期寿命的总成本（Y/NT）：1983年使用的那种大规模筛查、目前这种大规模筛查以及1993年使用CT的大规模筛查。
对于目前的大规模筛查方法，结果表明，当患者为55岁以下男性和65岁及以上女性时，成本会降低。1983年和1993年之间几乎没有差异，随着CT的引入，该比例略有增加。使用Y/N和Y/NT两个值观察成本效益。1993年50岁及以下女性的筛查成本低于1983年，但其他年龄组男性的筛查成本没有重大差异。引入CT后，Y/NT值变得更低。
结果表明，目前肺癌筛查所使用的方法成本较低，但其有效性也较低；而且，尽管CT筛查的成本高于目前的筛查方法，但其有效性要高得多。就成本效益而言，CT肺癌筛查应成为最合适的筛查方法。
