Relative risks (RR) were used to measure the strength of the associations among the risk of metachronous adenoma, cancers, adenomas with severe dysplasia and the characteristics of initial adenoma.

• 并分析首次筛查发现直肠腺瘤的病理学特征与发生直肠新生异时性腺瘤、重度不典型增生腺瘤和癌的关系及相对危险性。