TY - JOUR
T1 - Delayed sample arrival at the laboratory does not lead to more false negatives in the Danish population screening for colorectal cancer.
AU - Hansen, Anette Tarp
AU - Hoffmann-Lücke, Elke
AU - Niels , Bettina Klint
AU - Reinholt, Birgitte
AU - Hindersson, Peter
AU - Hornung, Nete
PY - 2017/12
Y1 - 2017/12
N2 - 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.
AB - 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.
KW - Clinical laboratory services
KW - colorectal neoplasms
KW - early detection of cancer
UR - http://www.scopus.com/inward/record.url?scp=85029697307&partnerID=8YFLogxK
U2 - 10.1080/00365513.2017.1379091
DO - 10.1080/00365513.2017.1379091
M3 - Journal article
C2 - 28933963
SN - 0036-5513
VL - 77
SP - 685
EP - 688
JO - Scandinavian Journal of Clinical & Laboratory Investigation
JF - Scandinavian Journal of Clinical & Laboratory Investigation
IS - 8
ER -