Impact of Cancer Genomics on Precision Medicine for the Treatment of Cancer
Precision medicine is a phrase that is often used to describe how genetic information about a person’s disease is being used to diagnose or treat their disease. Cancer is a disease of the genome and as more is learned about cancer tumors, the more we are finding that each tumor has its own set of genetic changes. Understanding the genetic changes that are in cancer cells is leading to more effective treatment strategies that are tailored to the genetic profile of each patient’s cancer.
Cancer genomics aims to advance personalized medicine through the DNA sequencing and analysis of patient tumors to find new genetic alterations associated with specific cancers. Providing researchers with comprehensive catalogs of the key genomic changes in many major types and subtypes of cancer will support advances in developing more effective ways to diagnose, treat and prevent cancer.
Genomic information has already helped to shape the development and use of some of the newest cancer treatments. For example, the drug imatinib (Gleevec) was designed to inhibit an altered enzyme produced by a fused version of two genes found in chronic myelogenous leukemia. Another example is the breast cancer drug trastuzumab (Herceptin), which works only for women whose tumors have a particular genetic profile called HER-2 positive. Studies have also found lung cancer patients whose tumors are positive for EGFR mutations respond to the drugs gefitinib (Iressa) and erlotinib (Tarceva) which target this mutation. On the other hand, colon cancer patients whose tumors have a mutation in a gene called KRAS derive little benefit from the drugs cetuximab (Erbitux) and panitumumab (Vectibix). The type of genomic information generated by TCGA and other cancer genomics projects will drive research to develop similar treatment strategies that will be most effective for a given set of genomic changes.