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An Alternative Pathway in Colorectal Carcinogenesis Based on the Mismatch Repair System and p53 Expression in Korean Patients with Sporadic Colorectal Cancer
Annals of Surgical Oncology, 07/05/2012
Kim HR et al. – According to the MSI and p53 subsets, colorectal cancers showed different clinicopathologic features, but these subsets had no prognostic impact on overall and disease–free survival rate.
Methods- Between 1999 and 2008, a total of 2,649 colorectal cancer patients were analyzed using a prospective database.
- A mismatch repair defect (MMR–D) was defined as a loss of expression of more than one MMR protein and/or MSI–high. MMR–proficiency (MMR–P) was defined as expression of all MMR proteins and microsatellite stable (MSS)/MSI–low.
- Groups 1 (G1), 2 (G2), 3 (G3), and 4 (G4) were defined as MMR–D and p53–positive expression, MMR–D and p53–negative expression, MMR–P and p53–positive expression, MMR–P and p53–negative expression, respectively.
- Eighty–two (3.0 %), 181 (6.8 %), 1,368 (51.7 %), and 1,018 (38.5 %) patients were classified into groups 1–4, respectively.
- Comparison between G1 and G2 showed differences in location (p < 0.001), size (p = 0.030), node metastasis (p = 0.027), distant metastasis (p = 0.009), and stage (p = 0.040).
- Comparison between G3 and G4 showed differences in location (p < 0.001) and histology (p < 0.001).
- Comparison between G1 and G3 showed differences in location (p < 0.001) and histology (p < 0.001).
- Comparison between G2 and G4 showed differences in age (p < 0.001), location (p < 0.001), size (p = 0.006), histology (p < 0.001), node metastasis (p < 0.001), distant metastasis (p < 0.001), and stage (p < 0.001).
- On multivariate analysis, stage (p = 0.007) and histology (p < 0.001) were associated with improved overall survival, and stage (p < 0.001) was associated with disease–free survival.
