Department of Surgery, University of Auckland, Auckland, New Zealand.
Dis Colon Rectum. 2011 May;54(5):552-8. doi: 10.1007/DCR.0b013e31820e3265.
In accordance with the Bethesda Guidelines, Auckland's metropolitan hospitals routinely perform immunohistochemistry for mismatch repair proteins on the tumor specimens of all patients with colorectal cancer aged 50 years and younger. When loss of expression is evident, patients are offered genetic counseling and gene mutation analysis.
This study aimed to determine the completeness of young patient capture over the first 7 years of routine testing, to find whether patients were referred for genetic testing, and to determine the proportion of patients found to have a mismatch repair gene mutation.
This study retrospectively reviewed clinical, pathological, and genetic data.
The study was conducted at 3 public hospitals in Auckland, New Zealand.
All patients aged 50 years and younger treated for colorectal cancer at Auckland's metropolitan hospitals between January 2001 and December 2007 (n = 243) were included.
The loss of expression of mismatch repair proteins by immunohistochemistry, referral for genetic testing, and proportion with mismatch repair gene mutation were the main outcome measures.
Two hundred fourteen (88%) eligible patients had immunohistochemical analysis of their tumor and 33 (14%) had loss of expression of one or more mismatch repair proteins. Twenty-six patients were referred for genetic counseling, of whom 22 underwent genetic testing. A mismatch repair gene mutation was identified in 10 patients.
Seven patients with loss of expression of mismatch repair proteins by immunohistochemistry were not referred for genetic assessment.
We have identified a mismatch repair gene mutation diagnostic of hereditary nonpolyposis colorectal cancer in 5% of all patients with colorectal cancer who were aged 50 years and younger. Routine immunohistochemical prescreening has important clinical benefit for these patients and their relatives.
根据 Bethesda 指南，奥克兰的都市医院常规对所有 50 岁及以下结直肠癌患者的肿瘤标本进行错配修复蛋白免疫组化检测。当表达缺失明显时，患者将获得遗传咨询和基因突变分析。
本研究旨在确定常规检测的前 7 年中年轻患者的捕获完整性，确定患者是否接受基因检测，并确定发现错配修复基因突变的患者比例。
本研究回顾性地分析了临床、病理和遗传数据。
该研究在新西兰奥克兰的 3 家公立医院进行。
所有在奥克兰都市医院接受结直肠癌治疗的 50 岁及以下患者（n = 243）均纳入研究。
免疫组化检测错配修复蛋白的表达缺失、接受基因检测的转诊情况以及发现错配修复基因突变的患者比例。
214 名（88%）符合条件的患者进行了肿瘤免疫组化分析，33 名（14%）存在一种或多种错配修复蛋白的表达缺失。26 名患者被转诊进行遗传咨询，其中 22 名接受了基因检测。在 10 名患者中发现了错配修复基因突变。
7 名免疫组化检测错配修复蛋白缺失的患者未被转诊进行遗传评估。
我们在所有 50 岁及以下结直肠癌患者中发现了 5%的遗传性非息肉病性结直肠癌的错配修复基因突变。常规免疫组化预筛选对这些患者及其亲属具有重要的临床意义。
