Narrator: This is Science Today. Researchers have discovered two key factors that predict a breast cancer patient's risk of developing subsequent invasive tumors. Doctors at the University of California, San Francisco, studied women who had been diagnosed with a common breast cancer called ductal carcinoma in situ, or DCIS. They found that those who presented with a breast lump were more likely to develop an invasive breast cancer.
Kerlikowske: The other thing we found which is really kind of interesting was a whole separate population, if you had a mammographically detected DCIS positive for biomarkers, you were much more likely to have a subsequent invasive cancer.
Narrator: But researcher Karla Kerlikowske explains that the study does have limitations. The two high-risk groups identified by the study made up only half of the women who went on to develop invasive cancers.
Kerlikowske: So there's another whole half that we're not able to identify, although we're working on other kinds of markers to try and figure out who people are that we couldn't identify.Narrator: For Science Today, I'm Larissa Branin.