The body normally eliminates cells with damaged DNA before they turn cancerous. But the body’s ability to do so goes down as we age. This is part of the reason why there is a higher risk of cancer later in life. Each person’s cancer has a unique combination of genetic changes. As the cancer continues to grow, additional changes will occur. Even within the same tumor, different cells may have different genetic changes.The genetic changes that contribute to cancer tend to affect three main types of genes—proto-oncogenes, tumor suppressor genes, and DNA repair genes. These changes are sometimes called “drivers” of cancer.
