直肠息肉摘除对直肠癌预防的前瞻性评价

Reducing incidence and mortality from rectal cancer by polypectomy: A prospective cohort study

目的 评估直肠镜在人群中筛检效果 ,验证直肠息肉摘除能否阻断直肠癌的自然史 ,降低直肠癌的发病率及死亡率。方法 1977～ 1980年间在海宁市分两次对 30岁以上 2 3余万人群进行 15cm肠镜筛检 ,对检出的 40 76例肠息肉进行镜下摘除后定期肠镜随访。结果 肠息肉患者经 2 0年定期肠镜随访 ,共计肠镜随访到并摘除肠腺瘤 95 2例次 ,非腺瘤性息肉 417例次 ,另外还随访检出肠癌 2 7例。直肠镜筛检检出的直肠癌的生存率显著高于同期非经筛检或随访检出的直肠癌的生存率 (P <0 .0 0 1) ,筛检使肠癌生存期延长了 7.89年。海宁市 1977～ 1996年的直肠癌的标化发病率与标化死亡率均有下降趋势 ;受干预人群的 2 0年累积直肠癌发病率与死亡率分别降低为 :6 8.6 %与82 .4%。结论 应用 15cm肠镜在人群中进行筛检 ,可提高直肠癌的生存率 ,对筛检检出肠息肉进行摘除并定期进行肠镜随访 ,可阻断直肠癌的自然史 。

Objective To address the hypothesis that colorectal cancers often arise from precursor lesion(s), either adenomas or nonadenomatous polyps. Methods A populationbased mass screening for rectal cancer using 15cm rigid endoscopy was conducted in Haining County, Zhejiang province, from 1977 to 1980. Of over 230 000 participants, 4 076 of them were diagnosed with precursor lesions, either adenomas or nonadenomatous polyps, which were then removed. All individuals with precursor lesions were followed and reexamined by endoscopy every two to five years through 1998.Results After the initial screening, 952 metachronous adenomas and 417 nonadenomatous polyps were detected and removed from the cohort. Furthermore, 27 cases of colorectal cancer were detected and treated. Logank tests showed that the years of survival significantly increased among those cancer patients who had undergone mass screening compared to other rectal cancer patients (P< 0.001 ).According to the populationbased cancer registry in Haining County, both ageadjusted incidence and mortality rates from rectal cancer decreased from 1977 to 1996. Observed accumulative incidence and mortality rates decreased to 68.6 % and 82.4 % comparing with expected numbers during the last 20 years. Conclusion Mass rectal cancer screening in the general population followed by routine endoscopy for highrisk patients could decrease both rectal cancer incidence and mortality rates.