Screening a woman's breast cancer for certain genetic and molecular patterns may be used to predict the risk of the cancer returning (relapsing) up to 20 years later, a study reports. Looking at the molecular data of breast tumors of nearly 2,000 women, researchers identified specific tumor types and created a model to predict the risk of long-term cancer relapse, as well as when and where in the body a tumor was more likely to spread. The findings may provide clinicians with an improved predictive tool to help guide them through treatment choices and improve the development of new breast cancer therapies. The study, “Dynamics of breast-cancer relapse reveal late-recurring ER-positive genomic subgroups,” was published in the journal Nature. One of the great challenges in breast cancer management has been to identify which women are at high risk of having the disease return years later. Doctors have relied primarily on characteristics such as size and grade of the tumor, the degree of lymph node involvement, and the presence or absence of hormone receptors for predicting disease course and choosing treatments.