X線検診との比較における胃内視鏡検診有効性評価

Evaluation of the Efficacy of Endoscopic Screening for Gastric Cancer Compared with X-ray Screening

要旨　有効性の証明された胃癌X線検診との比較を行うことで，内視鏡検診の評価を試みた．1995年度に対策型検診として間接X線による胃集団検診を受けた受診者36,876名と，1993～1995年に任意型検診として内視鏡検診を受けた受診者4,032名を対比した．X線検診での胃癌発見率0.14％，早期胃癌率68.6％，5年生存率78.4％より，内視鏡検診の胃癌発見率0.55％，早期胃癌率86.4％，5年生存率95.5％が勝っていた．検診で胃癌と診断されなかった受診者をわが国で最も届け出精度の高い福井県がん登録と照合した．検診を含めて5年以内の胃癌罹患率はX線検診受診者0.66％より内視鏡検診受診者1.26％で高率であり，内視鏡検診受診者の胃癌は有意に進展度が低い症例が多く，胃癌5年生存率はX線検診受診者80.4％より内視鏡検診受診者90.2％が良好であった．検診から5年目までに胃癌死亡した患者は内視鏡検診で2例，X線検診では41例であり，死亡率減少効果の面では両検診に統計的な差は認められなかったが，内視鏡検診のほうが上位であり，X線検診以上に内視鏡検診が有効であることが示唆された．

　The efficacy of endoscopic screening for gastric cancer was estimated in comparison with x-ray screening which has proven effectiveness in bringing about decreased gastric cancer death. We compared 4,032 participants examined with endoscopy during medical checkup from 1993 to 1995 and 36,876 participants surveyed by indirect X-rays in 1995. The detection rate for gastric cancer, early cancer rate and five year survival rate were 0.14％, 68.6％and 78.4％in x-ray screening and 0.55％, 86.4％and 95.5％in endoscopic screening, respectively. Each value was higher in endoscopic screening than in x-ray screening. The participants who were not diagnosed as having gastric cancer in these two screenings were referred to the Fukui cancer registry which is esteemed as the most accurate population based cancer registry in Japan. The prevalence rate of gastric cancer within five years after the initial screening was higher among the endoscopic screening participants (1.26％) than in the x-ray participants (0.66％). Since detected cancers among the endoscopic screening participants progressed significantly less, the five year survival rate was also higher among such participants (90.2％) than among the x-ray screening participants (80.4％). The number of gastric cancer deaths was 2 patients in the endoscopic screening group and 41 patients in the x-ray screening group. We did not find statistical difference regarding gastric cancer death between endoscopic screening and x-ray screening. It was concluded that endoscopic screening for gastric cancer was superior to x-ray screening when viewed from the aspect of decreased gastric cancer death.