Genetic tests for cancer have come a long way since they first entered the clinic in 1995. Back then, mutations in two genes - known as BRCA1 and BRCA2 - hinted at the crucial role that genetics can play in treatment decisions. Women carrying one of those mutations (and having a family history of breast or ovarian cancer) were much more likely than the general population to develop tumors in their breasts or ovaries. Then, as now, some of these women opted to have their breasts and ovaries removed before any malignant growths could arise.
"Cancer Gene Tests Provide Few Answers" is from the September 2016 issue of Scientific American.