As a woman ages her chances of being diagnosed with a low risk breast tumor increases. Women over 50 years old have too many cancers detected by mammograms that are not dangerous and lead to unnecessary biopsies and treatment with surgery, chemo, and radiation. UCSF researchers used a molecular testing device to determine the extent of malignancy breast cancers without metastases have and then correlated cancers from 20 years ago to the past decade and found that mammography revealed a large number of slow to moderate growth tumors in today's women compared to an era where mammograms were not done so routinely.