Nojo Takeshi, Imanaka Yuichi, Ishizaki Tatsuro, Sekimoto Miho, Yoshino Masahito, Kurosawa Takashi, Takao Hidemasa, Ohtomo Kuni
Department of Healthcare Economics and Quality Management, Graduate School of Medicine, Kyoto University, Yoshidakonoe-Cho, Sakyo-Ku, Kyoto 606-8501, Japan.
Lung Cancer. 2009 Jul;65(1):56-61. doi: 10.1016/j.lungcan.2008.10.004. Epub 2008 Nov 18.
Lung cancer incidence in general middle-aged men estimated by low-dose computed tomography screening has been unknown. We conducted a longitudinal study to estimate the incidence of lung cancer in general middle-aged Japanese men based on smoking status and to determine the optimal targets for lung cancer screening. The subjects were 14,058 Japanese men aged 40-59 years (mean age, 48.3 years; median age, 49 years) who underwent twice or more low-dose computed tomography screenings at Nippon Telegraph and Telephone East Corporation Izu Hospital at the baseline examination during 2000-2007. Medical records of subjects with abnormal findings were collected and analyzed. The lung cancer incidence in men aged 40-59 or 50-59 years based on smoking status by person-years method, and relative risks of current- and former-smokers compared with non-smokers were calculated. Mean follow-up period was approximately 3 years, and total person-years were 45,152. The incidence was 24.4 per 100,000 person-years in men aged 40-59 years (95% confidence interval (95% CI) 13.6-43.6), and 56.5 in men aged 50-59 (95% CI 31.6-101). No statistically significances were observed among non-, current- and former-smokers. However, the relative risk of the current-smokers aged 50-59 years with 40 or more pack-years, compared with non-smokers was 6.31 (95% CI 1.27-31.3), and was statistically significant. No significant differences in the lung cancer incidence existed among any smoking status in the Japanese men aged 40-59 years. In this population, men aged 50-59 years with 40 and more pack-years could be an optimal target for lung cancer screening. The small number of incident lung cancers resulting in the incidence and relative risks with the wide 95% CI and the participants' demographic biases were the limitations of our study. Our screening recommendations should be made with more caution.
通过低剂量计算机断层扫描筛查估算的一般中年男性肺癌发病率尚不清楚。我们进行了一项纵向研究，以根据吸烟状况估算日本一般中年男性的肺癌发病率，并确定肺癌筛查的最佳目标人群。研究对象为14,058名年龄在40 - 59岁（平均年龄48.3岁；中位数年龄49岁）的日本男性，他们于2000年至2007年在日本电报电话东公司伊豆医院进行了两次或更多次低剂量计算机断层扫描基线检查。收集并分析了检查结果异常者的病历。采用人年法计算了40 - 59岁或50 - 59岁男性基于吸烟状况的肺癌发病率，以及当前吸烟者和既往吸烟者与不吸烟者相比的相对风险。平均随访期约为3年，总人年数为45,152。40 - 59岁男性的发病率为每10万人年24.4例（95%置信区间（95%CI）13.6 - 43.6），50 - 59岁男性为56.5例（95%CI 31.6 - 101）。在不吸烟者、当前吸烟者和既往吸烟者之间未观察到统计学显著差异。然而，50 - 59岁、吸烟史40包年及以上的当前吸烟者与不吸烟者相比，相对风险为6.31（95%CI 1.27 - 31.3），具有统计学显著性。4,0 - 59岁的日本男性中，任何吸烟状况下的肺癌发病率均无显著差异。在该人群中，50 - 59岁、吸烟史40包年及以上的男性可能是肺癌筛查的最佳目标人群。本研究的局限性在于肺癌发病例数较少，导致发病率和相对风险的95%CI较宽，以及参与者存在人口统计学偏差。我们在提出筛查建议时应更加谨慎。
