Bernstein C N, Shanahan F, Weinstein W M
Department of Medicine, University of Manitoba, Winnipeg, Canada.
Lancet. 1994 Jan 8;343(8889):71-4. doi: 10.1016/s0140-6736(94)90813-3.
The recommended approach to the increased risk of colorectal carcinoma in ulcerative colitis has been colonoscopic surveillance rather than prophylactic colectomy. This strategy is based on the assumption that dysplastic lesions can be detected before invasive cancer has developed. We have analysed published reports on dysplasia surveillance to find out whether this assumption is valid. Ten prospective studies (1225 patients) satisfied our criteria. Of 40 patients with dysplasia-associated mass or lesion (DALM) detected, 17 (43%) already had cancer at immediate colectomy. The risks of cancer at immediate colectomy were 42% (10 of 24 patients) for high-grade and 19% (3 of 16) for low-grade dysplasia. Of 47 patients found to have high-grade dysplasia after the initial colonoscopy, 15 (32%) had cancer. 16-29% of patients with untreated low-grade dysplasia progressed to DALM, high-grade dysplasia, or cancer. Of patients with indefinite results, 28% progressed to high-grade dysplasia and 9% to cancer, so continued surveillance is essential. The risk of progression to dysplasia was only 2.4% for patients whose initial result was negative, so surveillance could perhaps be less frequent for these patients. Immediate colectomy is essential for all patients diagnosed with high-grade or low-grade dysplasia. A diagnosis of dysplasia does not preclude the presence of invasive cancer. We believe that patients should be informed about the limitations of colonoscopic surveillance so that they can take part rationally in decision-making about their management.
对于溃疡性结肠炎患者结直肠癌风险增加的推荐处理方法是结肠镜监测而非预防性结肠切除术。这一策略基于发育异常病变可在浸润性癌发生之前被检测到的假设。我们分析了已发表的关于发育异常监测的报告，以查明这一假设是否成立。十项前瞻性研究（1225例患者）符合我们的标准。在检测出的40例发育异常相关肿物或病变（DALM）患者中，17例（43%）在即刻结肠切除时已患有癌症。即刻结肠切除时的癌症风险，高级别发育异常患者为42%（24例中的10例），低级别发育异常患者为19%（16例中的3例）。在初次结肠镜检查后发现高级别发育异常的47例患者中，15例（32%）患有癌症。未经治疗的低级别发育异常患者中有16% - 29%进展为DALM、高级别发育异常或癌症。结果不确定的患者中，28%进展为高级别发育异常，9%进展为癌症，因此持续监测至关重要。初次检查结果为阴性的患者进展为发育异常的风险仅为2.4%，所以这些患者的监测频率或许可以降低。对于所有诊断为高级别或低级别发育异常的患者，即刻结肠切除是必要的。发育异常的诊断并不排除浸润性癌的存在。我们认为应告知患者结肠镜监测的局限性，以便他们能够理性地参与关于自身治疗的决策。
