For some women, the treatment for ductal carcinoma in situ (DCIS) may be even more aggressive than treatments undertaken for early-stage invasive disease. Expectant management is not a tenable alternative, given that in a significant percentage of patients, DCIS eventually progresses to invasive cancer. Nevertheless, if this progression could be halted or reversed with primary medical therapy alone, a significant portion of the 50,000 women diagnosed with DCIS in the United States annually could potentially avoid the morbidity of surgery and radiation for this disease. The most promising therapeutic candidates in this regard are those treatments targeting hormone receptors on breast cancer cells. We have initiated a clinical trial of neoadjuvant hormonal therapy for women with hormone receptor-positive DCIS. We discuss the clinical rationale and study design for this trial and present our preliminary results.