Live from the Biggest Science Conference in the World: Cancer, Genes, and the Environment

Why do some people smoke for a short time and develop lung cancer, while others who smoke for decades live to a ripe old age, cancer-free? And why do some women with BRCA mutations develop breast cancer, while others don’t? Our genes and our environment both contribute to our cancer risks, but exactly how these interactions work is a mystery. Cheryl Walker of the University of Texas M.D. Anderson Cancer Center says that clues to the puzzle can be found in the environment we were in before we were born. Her work shows that while developing in its mother’s uterus, a fetus may be exposed to estrogen, which can greatly impact the way the cells of the body respond when exposed to estrogen later in life. During pregnancy, a woman’s levels of progesterone and estrogen soar, but the fetus is protected from the effects of these hormones by natural antibodies. ...