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Evaluation of Colorectal Cancer Risk and Prevalence by Stool DNA Integrity Detection
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Factors affecting KRAS mutation detection in colorectal cancer tissue
Hyon-Goo Yun1, Hyun Joo Lee1, Bo-Ra Kim1
1Department of Pathology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
Pathology, Research and Practice
|March 9, 2019
Summary
Cold ischemia time significantly impacts KRAS mutation detection in colorectal cancer (CRC) DNA quality. Biopsy specimens offer better DNA quality than resection specimens, with shorter cold ischemia time being crucial for accurate KRAS testing.
Area of Science:
- Oncology
- Molecular Pathology
- Cancer Biomarkers
Background:
- Accurate molecular testing for biomarkers is vital in cancer diagnostics.
- The impact of pre-analytical variables like cold ischemia and formalin fixation time on KRAS mutation detection in colorectal cancer (CRC) remains unclear.
Purpose of the Study:
- To investigate the effects of cold ischemia time and formalin fixation time on DNA quality for KRAS mutation testing in colorectal cancer specimens.
- To identify factors influencing DNA quality in formalin-fixed, paraffin-embedded (FFPE) tissues.
Main Methods:
- Analysis of KRAS mutation test results from 401 colorectal cancer specimens.
- Evaluation of clinicopathologic factors including specimen type, cold ischemia time, and formalin fixation time.
- Assessment of DNA quality and KRAS mutation detection rates based on varying pre-analytical conditions.
Main Results:
- Biopsy specimens demonstrated superior DNA quality for KRAS testing compared to resection specimens, correlating with shorter cold ischemia and formalin fixation times.
- Cold ischemia time of one hour or less was associated with improved DNA quality.
- Formalin fixation time within routine diagnostic ranges did not significantly impact DNA quality, but prolonged fixation (1-3 months) progressively degraded DNA quality.
Conclusions:
- Biopsy specimens yield better DNA quality for KRAS mutation testing in colorectal cancer.
- Cold ischemia time is a critical factor influencing DNA quality in routine diagnostic pathology.
- Formalin fixation time allows for a broad optimal range, but extended durations negatively affect specimen integrity for molecular analysis.
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