Breast cancer is the most common cancer and the second cause of cancer mortality in women. There are approximately 200,000 new cases of breast cancer a year. Classically, breast cancers are divided into two groups, invasive and non-invasive. A mainstay of the treatment of both of these types is surgical resection not only for therapeutic purposes but also for diagnostic purposes. Breast conserving therapy includes surgical lumpectomy and post-operative radiation. However, despite best surgical practices, when patients undergo BCT anywhere from 20 - 40% of these patients have margins positive for cancer. This leads to increased rates of reoperation which are quoted to be as high as 30% and increased local recurrences.

There is an over expression of folate receptors located on the surface of many human carcinoma nodules.Specifically for breast cancer up to 33% of all breast cancers over express the folate receptor.

Folate-fluorescein isothiocyanate, or folate-FITC, also identified as EC-17, targets folate receptors over expressed in certain cancers such as breast cancer, and could help in better identifying the margins of the cancer thereby achieving negative margins.

Inclusion Criteria:

1. Adult patients 18 years of age and older
2. Patients presenting with breast cancer presumed to be resectable by lumpectomy and/or mastectomy on pre-operative assessment
3. Good operative candidate
4. Subject capable of giving informed consent and participating in the process of consent.

Exclusion Criteria:

1. Pregnant women as determined by urinary or serum beta hCG within 72 hours of surgery

2. Patients with a history of anaphylactic reactions to Folate-FITC or insects

3. At-risk patient populations

   1. "People who would be easily lost to follow up (ex: People who are homeless or alcohol dependent)
   2. Patients unable to participate in the consent process (children and neonates).