Findings from two studies presented at the annual San Antonio Breast Cancer Symposium showed an association between osteoporosis drugs and cancer risk. Data from the Women’s Health Initiative was used to retrospectively evaluate postmenopausal women for close to 8 years. Of the 151,592 women in the study, 2,216 were taking oral bisphosphonates (drugs to prevent bone loss) during the study period. Women taking bisphosphonates had 32% fewer new breast cancers compared to those who were not taking bisphosphonates. A study in Israel of 4,575 postmenopausal women found that women who used bisphosphonates had a 29% relative risk reduction for breast cancer. Although both sets of findings generated excited, there was also a certain amount of skepticism amount experts. Most agreed that there is an association between the bisphosphonates and breast cancer risk, but randomized controlled clinical trials are needed to prove the effect.