Colorectal Cancer: Molecular Staging Models that Charactrize Risk and Enhance Prognosis

Established staging models for colorectal cancer (CRC) have mostly been based on morphological and clinicopathological criteria, which, while predictive of outcomes at extreme stages (e.g., Dukes' A and D), are less informative at the intermediate stages (e.g., Dukes' B and C). Although this traditional staging has improved survival by adjuvant therapy, a significant percentage of patients develop locoregional recurrences or metastases to the liver and other organs after curative tumor resection. Therefore, it is important to explore the use of new molecular and biological markers, particularly those that provide clues to tumor aggressiveness, in order to target therapeutic outcomes. The clinical usefulness of markers may vary with ethnicity and the anatomical location of the tumor; thus, combinations of markers are needed to develop a "predictive gene expression index" that will identify the underlying potential of the tumor for successful spread to a distant site.