There is now ample evidence that detection and removal of colonic polyps can prevent colorectal cancer . early diagnosis of colorectal cancer will also improve efficacy of treatments and hence survival of this deadly condition 迄今为止,已有足够证据证明常规检查和去除癌前息肉可以有效预防癌症发生,早期检查及诊断亦有助提高治疗成效并减低死亡率。