Breast cancer is a leading cause of death among women in the U.S. Early diagnosis is believed to be key to minimizing mortality, thus, techniques to identify high-risk women are essential. This study is using an interdisciplinary approach to conduct a follow-up study on a group of 3413 women from the Santa Barbara, Ca area who had breast fluids drawn between 1970-1990 using one of the following three methods: nipple aspiration, ductography or ductal lavage. The follow-up study will determine if abnormal cytologic findings from the past are associated with a higher incidence of breast cancer development during the later years. Follow-up methods include direct contact using questionnaires, linkage with the California Cancer Registry (CCR), linkage with the California Department of Vital Statistics and the National Death Index. As of 5/04, the CCR has yielded information on 344 subjects, with a total of 386 tumors. The study hypothesis is that women with abnormal cytologic findings in breast fluid will be 2.0 - 5.0 times more likely to develop breast cancer than women with normal cytologic findings or women from whom no fluid could be obtained.