Genetic and epigenetic classifications define clinical phenotypes and determine patient outcomes in colorectal cancer

摘要: Background: A molecular classification of colorectal cancer has been proposed based on microsatellite instability (MSI), CpG island methylator phenotype (CIMP), and mutations in the KRAS BRAF oncogenes. This study examined prevalence these classes, differences clinical presentation outcome. Methods: Demographics, tumour characteristics survival were recorded for 391 subjects with cancer. Tumour DNA was analysed MSI (high (MSI-H) or stable (MSS)), CIMP (CIMP-H) no (CIMP-neg)) mutations. Clinical between four phenotypes examined. Results: Most tumours MSS/CIMP-neg (69·8 per cent), a nearly equal distribution MSI-H/CIMP-H, MSI-H/CIMP-neg MSS/CIMP-H types. less likely to be poorly differentiated (P = 0·009). CIMP-H more common older patients < 0·001). MSI-H/CIMP-H had high frequency mutation low rate mutation; opposite true The tended towards divergent 0·067 stages 1–III). MSI-H cancers associated better disease-free (hazard ratio 2·00 (95 cent confidence interval 1·03 3·91); P 0·040). Conclusion: Colorectal are molecularly clinically heterogeneous. These different may reflect variable prognosis. Copyright © 2009 British Journal Surgery Society Ltd. Published by John Wiley & Sons,