The journal Proceedings of the National Academy of Sciences published a study that examined mice that were given the breast cancer drugs fulvestrant and raloxifene, both of which work by preventing estrogen from functioning in cells, HealthDay News reports. The mice where genetically engineered to carry HPV, an STD strongly linked with cervical cancer. The drugs cleared precancerous growths in the cervix and prevented cancer in mice with precancerous lesions, according to the research.