Cancers of the Rectum and Anal Canal

Abstract

Personalized medicine utilizes the molecular basis of disease to provide tools to stratify risk and predict treatment effect; and in doing so provides the opportunity for rational design of cancer therapeutics. In particular, the genetic events associated with rectal and anal malignancies have been translated into clinical applications that now guide screening efforts, serve as targets for therapeutic agents, and can function as predictive markers for treatment outcomes. For example, evaluation for defective cellular DNA-mismatch repair and for activating somatic mutations in the K-ras proto-oncogene have moved into the clinical arena and considered standard of care for screening and treatment decision-making. In addition, the epidermal growth factor receptor and vascular endothelial growth factor are both treatment-directed targets that can alter the life expectancy in individuals with these diseases. Thus by leveraging the science of genomics, the promise of personalized cancer medicine is delivery of highly effective and minimally toxic prevention, screening, and treatment modalities that are tailored to the genetic makeup of each patient and to the unique molecular makeup of that individual’s tumor.