Rectal cancer genomics

Cellular signaling abnormalities play an important role in the oncogenesis of rectal cancer. These signaling changes are frequently driven by genomic changes. This review describes five commonly altered cell signaling pathways in rectal cancer: WNT, RAS, TGF-β, p53, and PI3K. For these pathways, both physiologic (non-altered) function and common mutations that contribute to abnormal signaling are described. As rectal cancer is driven by genomic changes, a discussion of the prognostic value of pathway signaling mutations is included. Lastly, the use of genomic changes as predictive markers for response to preoperative radiotherapy is described.