因胃肠道癌症而死亡的人较死于其它任何器官系统肿瘤者都多。多数胃肠道肿瘤常可经内镜检查及活检被发现,如能早期发现,则预后往往较好。对所有人行内镜筛选是不可能的,人力、物力、财力花费大。但一系列癌前病变已广为人们所认识,包括结肠息肉、胃及大肠的慢性炎症及Barrett’s粘膜。此外,遗传学研究业已证实家族史是胃肠道肿瘤发生的又一个因素,且已经证实有癌症家族史的病人对恶性肿瘤具有遗传易感性。在大宗人群筛选中发现,越来越多的病人有与恶变或癌前病变有关的生化或免疫学异常。此外,有些人易于发生恶性病变可能与其所处的环境有关。以上这些高危人群均适于监测,以便早期或在癌发生转移前发现病灶,并成功地采取治疗措施。 There are more people who die from gastrointestinal cancer than those who die from any other organ system tumor. Most gastrointestinal cancers are often found by endoscopy and biopsy. If they are detected early, the prognosis is often better. Endoscopic screening of all people is impossible, and human, material and financial resources are expensive. However, a series of precancerous lesions have been widely known, including colonic polyps, chronic inflammation of the stomach and large intestine, and Barrett’s mucous membranes. In addition, genetic studies have confirmed that family history is another factor in the development of gastrointestinal cancer, and patients with a family history of cancer have been confirmed to have genetic susceptibility to malignant tumors. In large population screening, more and more patients have biochemical or immunological abnormalities associated with malignant or precancerous lesions. In addition, some people are prone to malignancy that may be related to their environment. All these high-risk groups are suitable for monitoring so that lesions can be discovered early or before the cancer is transferred, and successful treatment measures can be taken.