The risk of cancer is partly determined by inherited factors (genetic variants). By identifying these genetic variants, we can identify groups of people who are an enhanced risk of cancer and, where possible, offer them measures to reduce that risk. Some of the genetic variants may have a major effect (e.g. ten-fold increased risk), whereas others may only affect risk by about 10%. Nevertheless, as many genetic variants are expected to influence cancer risk, multiple variants with modest effects can add up to cause considerable variation in cancer risk in the general population. Identifying cancer risk genes can also indicate the underlying mechanisms of cancer growth. It is possible that we can develop new ways of preventing cancer as a result, similar to how we prevent heart disease and strokes by regular medication or lifestyle changes.
