Chemoprevention agents are medications or vitamins taken to reduce the risk for development of a specific cancer. Early phase clinical research of chemoprevention agents has many unique challenges. In particular, the effect of a potential chemoprevention agent is ideally evaluated not only in normal tissue, but also in malignant tissue. At the same time, the usual parameters of pharmacokinetics, toxicity, and drug tolerance must be evaluated. As assessing target tissue for effect of the agent is a primary goal of these studies, one must also consider the best approach to obtain adequate tissue samples while limiting the amount of risk and discomfort to the study participant. Although study designs vary depending on the organ sites of interest, in breast cancer chemoprevention studies, the most common techniques for obtaining breast tissue in patients without a breast cancer diagnosis have included nipple aspiration, ductal lavage, or four-quadrant fine needle aspirations.1 These techniques have varying strengths, but significant limitations of all of these techniques include the relatively low volume of cell/tissue retrieval, mixing of both normal epithelial cells and neoplastic cells (if present) during the collection procedure, and the limited stromal tissue acquisition.1–4 The treatment of solid tumors frequently involves a 2- to 6-week evaluation period between a diagnostic biopsy and the medically necessary surgical resection of the neoplasm, called the preoperative window. Research groups have leveraged the preoperative window for early phase studies of novel chemoprevention agents in various organs (ie, breast, prostate, and bladder).5–7 In these window-of-opportunity studies, patients receive study drug or placebo during the preoperative window. Then, at the time of the planned surgical resection of the identified neoplasm, extra neoplastic and normal tissues are obtained and subsequently analyzed for changes in surrogate endpoint biomarkers. While there are drawbacks to this window-of-opportunity approach, the main advantages are the ability to obtain relatively large sections of normal and neoplastic tissue that can be used for assessment of the chemoprevention agent’s effects on multiple biomarkers. In addition, the researcher can obtain this tissue without exposing the participant to the risk and discomfort of an additional invasive procedure. This window-of-opportunity approach is also being used to study the biologic effect of new targeted agents for the treatment of various cancers.8–12 It is worthwhile to note that for chemoprevention agents, the access to pre-treatment normal and tumor tissue continues to be limited with this approach, as core biopsies are the mainstay for diagnosis for the majority of cancers. Thus, placebo-controlled studies are often utilized. One common critique of the preoperative window-of-opportunity model is that it can lead to delays in potentially curative surgery that may affect survival outcomes. A review published in the International Journal of Clinical Practice13 summarized the published evidence about diagnostic evaluation leading to delays in breast cancer treatment. The review concluded that there was mixed evidence about whether delay in curative surgery may affect outcomes, but the main evidence supports that less than a 12-week delay has little to no effect on survival from breast cancer. However, one main issue with many of the reviewed studies was a failure to control for lead-time bias, which is the variability in delay between the patient detecting a symptom, presenting to the physician, diagnosis, and finally treatment. Another analysis specifically evaluating the impact of window-of-opportunity studies across multiple tumor types did not note any impact on survival.14 However, to limit any risk, window-of-opportunity clinical trial designs often incorporate a flexible treatment window to allow for variation in the surgical waiting period seen at different institutions and to enroll all participants who would take the minimum amount of treatment. Other designs may ask directly for a woman to delay surgery for a period while taking the study treatment for a fixed period of time. Although early phase clinical research trials for preventive drug development is critical, enrollment of a sufficient number of eligible patients to preoperative early phase chemoprevention studies has been a challenge across many different tumor types.15 Barriers to participation are multiple and may include protocol requirements or exclusions, alternative therapeutic research studies excluding prior neoplastic therapies, concerns about delay of standard therapy, or because the participant is not interested in participating in the specific research study or any research study. Our own experience in preoperative chemoprevention trials for prostate and bladder cancer has observed approximately 10% of screened participants were subsequently enrolled in the trial.16 Several breast cancer window-of-opportunity trials have been conducted with novel chemopreventive agents.10, 17–19 In these trials, the main factors that contribute to nonparticipation seem to be primarily related to protocol requirements or exclusions. However, also important to these studies are the large numbers of potential participants that are screened by recruiters or referred to the study but do not have any evidence of cancer in subsequent follow-up evaluations. In a preoperative trial of tamoxifen, 46% of screened potential participants with a suspicious mammogram did not have any evidence of cancer on a follow-up core biopsy. Only 1% of screened patients were enrolled in this study.20 Thus, despite literature that supports window-of-opportunity studies as being safe and providing ideal access both to normal and tumor tissue, enrollment in these studies remains low. The purpose of this current study was to determine predictors of willingness to participate in a preoperative chemoprevention study at our center, the University of Wisconsin Carbone Cancer Center (UWCCC), using a prospective survey of women recently recommended to undergo curative breast surgery for breast neoplasia.