All the DNA contained in your cells makes up your genome. In most cells, the genome is packaged into two sets of chromosomes: one set from your mother and one set from your father. These chromosomes are composed of six billion individual DNA letters. In the English alphabet there are 26 letters: A through Z. In the alphabet of our genes there are four letters: A, C, G and T. Just like the letters in a book make words to tell a story, so do the letters in our genomes. Genomics is the study of the sequence of these letters in your DNA and how each string of letters passes information to help each cell in your body work properly.
In cancer cells, small changes in the genetic letters can change what a genomic word or sentence means. A changed letter can cause the cell to make a protein that doesn’t allow the cell to work as it should. These proteins can make cells grow quickly and cause damage to neighboring cells. By studying the cancer genome, scientists can discover what letter changes are causing a cell to become a cancer. The genome of a cancer cell can also be used to tell one type of cancer from another. In some cases, studying the genome in a cancer can help identify a subtype of cancer within that type, such as HER2+ breast cancer. Understanding the cancer genome may also help a doctor select the best treatment for each patient.
To learn more about genomics and cancer, view the following resources: