Hansen Anette Tarp, Hoffmann-Lücke Elke, Nielsen Betina Klint, Reinholdt Birgitte, Hindersson Peter, Heidemann Karin, Hornung Nete
a Department of Clinical Biochemistry , Randers Regional Hospital , Randers , Denmark.
b Department of Clinical Biochemistry , Aalborg University Hospital , Aalborg , Denmark.
Scand J Clin Lab Invest. 2017 Dec;77(8):685-688. doi: 10.1080/00365513.2017.1379091. Epub 2017 Sep 21.
In Denmark, biennial population screening for colorectal cancer was introduced in 2014 for all aged 50-74 years. Five laboratories representative for the regional division of Denmark perform the immunochemical testing of faecal occult blood in the screening samples (iFOBT, OC-Sensor (Eiken Chemical, cut-off 100 µg/L)). In July 2016, a new agreement on the public post-delivery entailed an increased lag time (five days) from the screening participant drops the screening sample into a mail-box until sample arrival at the laboratories. Previous work had reported that a lag time above five days led to more false negative iFOBT tests. We investigated if this was true also under Danish conditions. We performed two stability tests; one with sample storage at 30 °C for 14 days (N = 60), and another with sample storage at room temperature for 13 days (N = 10). We extracted data from our laboratory information system (LABKA) on all iFOBT tests performed in the entire Central Denmark Region (N = 104,328 patients) during the last six months for each calendar year 2014-16. For each year, we computed the distribution of iFOBT tests below and above cut-off. Our stability tests showed no positive samples switching to false negative after storage; however, some negative samples turned false positive, especially at 30 °C. The data showed no change in the distribution of iFOBT tests below and above cut-off after July 2016. We found no evidence that an enhanced lag time increased the number of false negative iFOBT tests in the Danish screening program for colorectal cancer.
在丹麦，2014年开始对所有50至74岁的人群进行两年一次的结直肠癌群体筛查。丹麦地区划分的五个具有代表性的实验室对筛查样本进行粪便潜血的免疫化学检测（免疫化学法粪便潜血检测，OC-Sensor（荣化学工业株式会社，临界值100μg/L））。2016年7月，一项关于公共产后的新协议导致从筛查参与者将筛查样本放入邮箱到样本送达实验室的延迟时间增加（五天）。此前有研究报告称，延迟时间超过五天会导致免疫化学法粪便潜血检测出现更多假阴性结果。我们调查了在丹麦的条件下情况是否也是如此。我们进行了两项稳定性测试；一项是将样本在30°C下储存14天（N = 60），另一项是将样本在室温下储存13天（N = 10）。我们从实验室信息系统（LABKA）中提取了2014 - 2016年每个日历年最后六个月在丹麦中部地区进行的所有免疫化学法粪便潜血检测的数据（N = 104,328名患者）。对于每一年，我们计算了免疫化学法粪便潜血检测结果低于和高于临界值的分布情况。我们的稳定性测试表明，储存后没有阳性样本转为假阴性；然而，一些阴性样本转为了假阳性，尤其是在30°C时。数据显示，2016年7月之后，免疫化学法粪便潜血检测结果低于和高于临界值的分布没有变化。我们没有发现证据表明延长的延迟时间会增加丹麦结直肠癌筛查项目中免疫化学法粪便潜血检测的假阴性数量。
