TY - JOUR
T1 - The homogeneous mutation status of a 22 gene panel justifies the use of serial sections of colorectal cancer tissue for external quality assessment
AU - Dijkstra, Jeroen R.
AU - Tops, Bastiaan B.J.
AU - Nagtegaal, Iris D.
AU - van Krieken, J. Han J.M.
AU - Ligtenberg, Marjolijn J.L.
N1 - Publisher Copyright:
© 2015, The Author(s).
PY - 2015/10/1
Y1 - 2015/10/1
N2 - Testing for treatment related biomarkers in clinical care, like Ras mutation status in colorectal cancer (CRC), has increased drastically over recent years. Reliable testing of these markers is pivotal for optimal treatment of patients. Participation in external quality assessment (EQA) programs is an important element in quality management and often obligatory to comply with regulations or for accreditation. Formalin-fixed paraffin-embedded (FFPE) clinical specimens would ideally form the basis for these assessments, as they represent the most common starting material for molecular testing. However, molecular heterogeneity of a lesion in a FFPE tissue block could potentially affect test results of participating laboratories, which might compromise reliability of the quality assessment results. To assess the actual impact of this potential problem, we determined the mutation status of 22 genes commonly mutated in colon cancer in four levels covering 360 μm of 30 FFPE tissue blocks, by Next Generation Sequencing. In each block, the genotype of these genes was identical at all four levels, with only little variation in mutation load. This result shows that the mutation status of the selected 22 genes in CRC specimens is homogeneous within a 360 μm segment of the tumor. These data justify the use of serial sections, within a defined segment of a CRC tissue block, for external quality assessment of mutation analysis.
AB - Testing for treatment related biomarkers in clinical care, like Ras mutation status in colorectal cancer (CRC), has increased drastically over recent years. Reliable testing of these markers is pivotal for optimal treatment of patients. Participation in external quality assessment (EQA) programs is an important element in quality management and often obligatory to comply with regulations or for accreditation. Formalin-fixed paraffin-embedded (FFPE) clinical specimens would ideally form the basis for these assessments, as they represent the most common starting material for molecular testing. However, molecular heterogeneity of a lesion in a FFPE tissue block could potentially affect test results of participating laboratories, which might compromise reliability of the quality assessment results. To assess the actual impact of this potential problem, we determined the mutation status of 22 genes commonly mutated in colon cancer in four levels covering 360 μm of 30 FFPE tissue blocks, by Next Generation Sequencing. In each block, the genotype of these genes was identical at all four levels, with only little variation in mutation load. This result shows that the mutation status of the selected 22 genes in CRC specimens is homogeneous within a 360 μm segment of the tumor. These data justify the use of serial sections, within a defined segment of a CRC tissue block, for external quality assessment of mutation analysis.
KW - Colon
KW - Mutant allele frequency
KW - RAS
KW - Reproducibility
UR - http://www.scopus.com/inward/record.url?scp=84940603877&partnerID=8YFLogxK
U2 - 10.1007/s00428-015-1789-5
DO - 10.1007/s00428-015-1789-5
M3 - Article
C2 - 26047774
AN - SCOPUS:84940603877
SN - 0945-6317
VL - 467
SP - 273
EP - 278
JO - Virchows Archiv
JF - Virchows Archiv
IS - 3
ER -