For a clinical trial to yield useful results, researchers usually must restrict the patients who participate, so certain factors won't throw off the conclusions. To do this, they set up specific eligibility criteria, often called inclusion criteria and exclusion criteria. For example, inclusion criteria for the trial of a new chemo agent might specify that the trial is recruiting patients who've already undergone a mastectomy -- or the opposite may be true; researchers may want only patients who haven't yet undergone surgery.
Many times, some criteria will be indicated in the name of the trial itself, but it's best to read through the study methodology to see if it's a good fit. Researchers may exclude for age, gender, use of other medications, or complicating health conditions.
Try to narrow your search using any information you have about the specifics of your breast cancer. Details that can narrow your search include whether the breast cancer is metastatic (meaning it has spread beyond the original area) or recurrent, the type of tumor involved, and any drug or therapy regimen used. So, for example, a clinical trial for breast cancer might specify that it's only for patients who've undergone a modified radical mastectomy for a tumor that's estrogen receptor-positive and has not yet been treated with radiation.
