原发腺瘤的病理学特征预测直肠异时性腺瘤的发生

Pathologic features of initial adenomas as predictors for metachronous adenomas of the rectum

目的 探讨直肠原发腺瘤的病理学特征与直肠异时性腺瘤再发的关系。方法 自 1977年至 1978年用 15cm直肠镜对海宁县 185 85 1居民进行直肠肿瘤筛查 ,共发现 1490例直肠腺瘤患者。这些患者在直肠腺瘤切除后 ,用内镜检查方法分别于第 2、4、6、11及 16年进行随访 ,观察直肠有无新生的异时性腺瘤。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。结果 随访中发现 2 80例患者在直肠内发生了新腺瘤。具有 2个以上的原发腺瘤、原发腺瘤直径大于 1cm、绒毛状 /混合型和中、重度不典型增生腺瘤患者发生异时性腺瘤的危险性升高 2～ 3倍 ,具有统计学意义。大于 1cm腺瘤 ,绒毛状 /混合型腺瘤及重度不典型增生腺瘤与发生癌或异时性重度不典型增生腺瘤明显相关 ,其相对危险性分别为 4 2 (1 8～ 9 9)、8 1(4 2～ 15 6 )和 14 4(5 0～ 41 3)。与伴轻度不典型增生、小于或等于 1cm腺瘤的患者相比 ,伴重度不典型增生、超过 1cm腺瘤的患者发生异时性直肠肿瘤的相对危险性为 37(7 8～174 7)。结论 直肠异时性腺瘤的危险性与原发腺瘤的病理学特征密切相关 ,因此 ,在高危组腺瘤患者的原发腺瘤切除后 ,应对他们进行密切监视。

Objective To study the relationship between the pathologic characteristics of initial adenoma and the risk of metachronous adenoma. Methods 185 851 people in Haining county from 1977 to 1978 were observed by means of a screening examination with a 15 cm rigid sigmoidoscope and 1 490 patients with rectal adenoma were found. They were followed up by endoscopic examination at year 2, 4, 6, 11, and 16 after their initial polypectomy, finding the recurrence of metachronous adenomas and the formation of cancer in the rectum. 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. Results New adenomas in the rectum were identified in 280 patients among these follow up cases. Statistically significant twofold to threefold elevated risks of metachronous adenoma were observed in patients with more than two initial adenomas, adenoma size beyond 1.0 cm, villous/tubulovillous type of pathology and moderate to severe dysplasia. Much stronger associations were observed for advanced metachronous neoplasms, which were defined as cancers or adenomas with severe dysplasia, with multi variate adjusted relative risks (95% confidence interval) of 4.2 (l.8～9.9) for a large initial adenoma (>1.0cm), 8.1 (4.2～15.6) for villous/tubulovillous architecture, and 14.4 (5.0～41.3) for severe dysplasia. In particular, patients who had a large (>1.0 cm) adenoma with severe dysplasia at baseline had a relative risk of 37 (7.8～174.7) of developing advanced metachronous neoplasms as compared with patients who had small adenomas with mild dysplasia. Conclusion The risk of metachronous adenoma is closely related to the pathologyof initial adenomas, thus allowing identification of a high risk group of adenoma patients for close surveillance after their initial polypectomy.