Taking a Personalized Medicine Approach to Breast and Colon Cancer

Abstract

One’s susceptibility to cancer is influenced by many proteins, including those involved in cell signaling and proliferation pathways, repair of DNA damage, the mitotic cycle and apoptosis. Several relatively rare but highly penetrant alleles that increase one’s risk for breast or colon cancer have been identified. In addition, a significant number of more common, but less penetrant, risk-increasing alleles have been identified as well. The chapter includes an extensive discussion of hereditary breast-ovarian cancer syndrome, BRCA gene testing, and a case report that illustrates how BRCA testing can be used to estimate risk for your patient and his/her family members. The chapter also includes discussions of Lynch syndrome and familial adenomatous polyposis, and the genetic and immunohistochemical tests that can be done to diagnose and predict risk for family members. Genetic tests have already been developed that classify patients with certain cancers into subgroups according to their molecular pathology. These tests are guiding the choice of treatments for patients with certain cancers. In addition, several gene variants are known to influence the pharmacokinetics or pharmacodynamics of specific anti-cancer drugs. The chapter also includes a list of Internet websites that will analyze family history and personal data and calculate one’s risk for developing breast cancer.