Molecular Classification of Colon Cancer: Perspectives for Personalized Adjuvant Therapy

Abstract

Although surgery for early-stage colorectal cancer (CRC) is often curative, many patients require adjuvant chemotherapy to treat micrometastatic disease and to reduce the risk of recurrence. Targeted therapies have improved outcomes for patients with metastatic disease but, in the adjuvant setting, options are limited to a fluoropyrimidine alone or in combination with oxaliplatin. There is an unmet need for new predictive biomarkers to personalise treatment in the adjuvant setting. With goals to address this gap and to better characterise disease heterogeneity, several groups including our own have identified three to six gene expression subtypes that were later consolidated into consensus molecular subtypes as part of the Colorectal Cancer Subtyping Consortium (CRCSC) effort. In this review, we discuss the differences and similarities between these subtypes and their potential prognostic and predictive values. We question whether a personalised treatment approach based on CRC subtypes might be beneficial in the adjuvant setting to improve treatment options and ultimately patient outcomes.