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Updated: May 14, 2026
06:01
A Genetically Engineered Mouse Model of Sporadic Colorectal Cancer
Published on: July 6, 2017
Colorectal carcinomas with KRAS mutation are associated with distinctive morphological and molecular features
Christophe Rosty1, Joanne P Young, Michael D Walsh
1Cancer and Population Studies Group, Queensland Institute of Medical Research, Herston, Queensland, Australia. c.rosty@uq.edu.au
Summary
KRAS-mutated colorectal carcinomas, common in 28% of cases, often arise near polyps and show distinct molecular features. These tumors do not impact overall survival but have unique pathological characteristics.
Area of Science:
- Oncology
- Gastroenterology
- Molecular Biology
Background:
- KRAS mutations are prevalent in colorectal carcinomas (35-40%).
- Limited understanding of KRAS-mutated colorectal carcinoma characteristics exists.
- This study investigates the pathological and molecular profiles of these tumors.
Purpose of the Study:
- To examine pathological and molecular features of KRAS-mutated colorectal carcinomas.
- To compare KRAS-mutated tumors with other colorectal carcinoma subgroups.
- To identify distinct characteristics associated with KRAS mutations.
Main Methods:
- KRAS mutation testing on 776 incident tumors from the Melbourne Collaborative Cohort Study.
- Assessment of O(6)-methylguanine DNA methyltransferase (MGMT) status via immunohistochemistry and MethyLight.
- Microsatellite instability (MSI) and BRAF V600E mutation status derived from prior studies.
Main Results:
- KRAS mutations found in 28% of colorectal carcinomas.
- KRAS-mutated tumors more frequently contiguous with polyps (38% vs 21%) and showed mucinous differentiation (46% vs 31%).
- Associated with distinct MSI status and higher MGMT methylation (47% vs 21%) compared to wild-type.
Conclusions:
- KRAS-mutated colorectal carcinomas exhibit unique molecular and pathological features.
- These tumors frequently develop adjacent to polyps.
- No significant difference in overall survival was observed based on KRAS mutation status.
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