尽管进行了结肠镜监测仍发生的异时性结直肠癌的特征

Characteristics of metachronous colorectal carcinoma occurring despite colonoscopic surveillance.

作者信息

Leggett B A, Cornwell M, Thomas L R, Buttenshaw R L, Searle J, Young J, Ward M

机构信息

Glaxo Gastroenterology Research Laboratory, Royal Brisbane Hospital Clinical Research Center, Bancroft Center, Royal Brisbane Hospital, Herston, Australia.

出版信息

Dis Colon Rectum. 1997 May;40(5):603-8. doi: 10.1007/BF02055387.

DOI:10.1007/BF02055387

PMID:9152192

Abstract

PURPOSE

Metachronous colorectal cancer still occurs in a small percentage of patients, despite colonoscopic surveillance. Cancers in hereditary nonpolyposis colorectal cancer for which there is a high risk of metachronous cancer show distinctive DNA changes termed replication errors (RER+). Ten to 20 percent of sporadic colorectal cancers are also RER+. The aim of this study was to identify factors predictive of metachronous colorectal cancer, despite colonoscopic surveillance. Clinicopathologic characteristics and RER status of cancers were examined.

METHODS

Colorectal cancer patients, who entered into a surveillance program of being examined with colonoscopy within six months of surgery and then at intervals of three years thereafter, were reviewed. The 433 patients compliant with the protocol who had had more than one colonoscopy had been followed up for a mean of 3.8 +/- 2.2 years. DNA was extracted from archival paraffin-embedded cancer tissue for determination of RER status.

RESULTS

Ten cases of metachronous cancer were identified, giving a rate of 0.61 percent per year. The site of the index cancer in patients who later developed metachronous cancer was predominantly proximal (P = 0.0007), and these cancers were more likely to have mucinous histology (P < 0.0005). Three of 10 (30 percent) index cancers were RER+, which was not significantly different from unselected series of control colorectal cancers in which 20 of 108 (18.5 percent) were RER+.

DISCUSSION

This study documents the rate of metachronous cancer among patients compliant with a defined colonoscopic screening program and suggests that the risk is highest in patients with a proximal mucinous cancer. RER status does not appear to be a very strong predictive factor, and this study does not support its use as a guide to the frequency of surveillance colonoscopy. More data would be required to determine if RER positivity conferred a relative risk of 3.3 or less.

摘要

目的

尽管进行了结肠镜监测，但异时性结直肠癌仍在一小部分患者中发生。遗传性非息肉病性结直肠癌患者发生异时性癌的风险很高，其癌症表现出独特的DNA变化，称为复制错误（RER+）。散发性结直肠癌中有10%至20%也是RER+。本研究的目的是确定尽管进行了结肠镜监测，但仍能预测异时性结直肠癌的因素。研究检查了癌症的临床病理特征和RER状态。

方法

对结直肠癌患者进行回顾，这些患者在手术后6个月内接受结肠镜检查，并在此后每3年进行一次检查，纳入监测计划。433例符合方案且接受过不止一次结肠镜检查的患者平均随访了3.8±2.2年。从存档的石蜡包埋癌组织中提取DNA，以确定RER状态。

结果

确定了10例异时性癌，每年发生率为0.61%。后来发生异时性癌的患者中，原发癌的部位主要在近端（P = 0.0007），这些癌症更可能具有黏液组织学特征（P < 0.0005）。10例原发癌中有3例（30%）为RER+，与未选择的对照结直肠癌系列相比无显著差异，后者108例中有20例（18.5%）为RER+。