tailieunhanh - Classification of colorectal cancer based on correlation of clinical, morphological and molecular features

The Cancer Centers Program also recognizes that many high quality, cancer-relevant research projects are funded by other organizations such as the Department of Energy (DOE), Department of Defense (DOD), Department of Agriculture (DOA), the Center for Disease Control and Prevention (CDC), State Health Departments etc. While funding from these organizations should not represent the major component of a cancer center's research base, the Cancer Centers Program wishes to provide all centers the option of carefully defending selected projects of special importance to the center for full access to CCSG resources. With this intent in mind, multi-year projects, which are equivalent. | Histopathology 2007 50 113-130. DOI REVIEW Classification of colorectal cancer based on correlation of clinical morphological and molecular features J R Jass Department of Pathology McGill University Montreal Canada Jass J R 2007 Histopathology 50 113-130 Classification of colorectal cancer based on correlation of clinical morphological and molecular features Over the last 20 years it has become clear that colorectal cancer CRC evolves through multiple pathways. These pathways may be defined on the basis of two molecular features i DNA microsatellite instability MSI status stratified as MSI-high MSI-H MSI-low MSI-L and MS stable MSS and ii CpG island methylator phenotype CIMP stratified as CIMP-high CIMP-low and CIMP-negative CIMP-neg . In this review the morphological correlates of five molecular subtypes are outlined Type 1 CIMP-high MSI-H BRAF mutation Type 2 CIMP-high MSI-L or MSS BRAF mutation Type 3 CIMP-low MSS or MSI-L KRAS mutation Type 4 CIMP-neg MSS and Type 5 or Lynch syndrome CIMP-neg MSI-H . The molecular pathways are determined at an early evolutionary stage and are fully established within precan-cerous lesions. Serrated polyps are the precursors of Types 1 and 2 CRC whereas Types 4 and 5 evolve through the adenoma-carcinoma sequence. Type 3 CRC may arise within either type of polyp. Types 1 and 4 are conceived as having few if any molecular overlaps with each other whereas Types 2 3 and 5 combine the molecular features of Types 1 and 4 in different ways. This approach to the classification of CRC should accelerate understanding of causation and will impact on clinical management in the areas of both prevention and treatment. Keywords cancer classification colorectal DNA methylation microsatellite instability pathways Abbreviations CIMP-high -low or -neg CpG island methylator phenotype-high -low or negative CIN chromosomal instabilty CRC colorectal cancer MSI microsatellite instability MSI-H microsatellite .