Beginner's guide to genetics: Cancer genetics
In the fifth part of our series, Adrián J González and colleagues take you through the genetic basis of cancer
Cancer starts in a cell that loses genetic control. It always begins with one cell (an aberrant precursor) and then grows to give rise to a population of cells. This group of cells grow in a disorderly manner becoming different from the precursor. They have increased metabolism, divide rapidly, and develop certain characteristics, such as the ability to colonise new sites. These characteristics give cancerous cells an evolutionary advantage compared with normal cells.
Cells are constantly dividing. Genetic material is always duplicated and distributed in new cells. This high mobility of DNA increases the risk of mutations. Apart from the inherent risks involved in DNA duplication and cell division, carcinogens found in the environment--such as ultra violet radiation, hormones, or tobacco smoke--can disrupt the integrity of genetic information.
Often errors in DNA structure do not cause serious problems. Although changes in DNA occur every day, only one of 1000 accidental