Cancers in the Urban Environment, Second Edition: Chapter 9: Recognizing Risky Genes

Investigators may often suspect that genetic variants enhance the risk of a cancer, but rarely they can use them to predict a truly high cancer risk. When scientists first recognized that a single kind of cancer tended to cluster in the members of a family, methods were devised to zero in on the specific determinants, in the hope that the investigation would result in specific forms of protection. Often the first step was to compare relatives of cases in general to relatives of similar healthy persons, giving an idea of the importance of the family connection.