Principal investigator left the study institution.

This research study is studying a PET imaging tracer as a possible means of imaging breast cancer.

The imaging agent involved in this study is:

-[11C]Martinostat (called C-eleven-Martinostat)

This research study is a Pilot Study, which is the first time investigators are examining this study imaging agent in patients who have breast cancer.

The FDA (the U.S. Food and Drug Administration) has approved [11C]Martinostat as an investigational tracer (a type of dye used to for radiographic imaging) in a select few research studies. The FDA has not approved this tracer for any use outside of research.

In this research study, the investigators are investigating the use of a PET tracer called [11C]Martinostat in patients with breast cancer.

The purpose of the study is to take images that can measure the amount of a protein called histone deacetylase, or 'HDAC' in breast tumors. Proteins are molecules made from amino acids that perform activities in the cell for the body to function in a healthy way. Prior research suggests that HDAC levels or amounts can be altered in some breast tumors. The investigators are trying to develop a method of imaging the HDAC protein in breast tumors. This could help them to study protein changes that occur in some breast tumors, and potentially help guide treatment of breast tumors in the future.

In this study, the investigators will take the pictures of the participant's chest, including the breasts, using a PET/MRI scanner. The investigators will the study tracer, or dye, called [11C]Martinostat to make these detailed pictures.

[11C]Martinostat was initially developed to image the HDAC protein within the brain, because amounts or levels of HDAC can be altered in some diseases of the brain. In these previous studies of [11C]Martinostat conducted in humans, there were no adverse events (there have been no problems). While this is not the first time [11C]Martinostat has been used in humans, it is the first study in which the investigators are using this tracer to study breast cancer.

Inclusion Criteria:

• Be at least 18 years or age (required for legal consent)
• Have ECOG performance status ≤2 (Karnofsky ≥60%, see Appendix A)
• Have breast imaging findings from mammogram, ultrasound, or breast MRI that are highly suspicious (i.e. coded as BI RADS 5) for breast cancer.
• Have primary breast tumor that is at least 2 cm in diameter as measured in any dimension on either mammogram, ultrasound, or breast MRI
• Have the ability to understand and the willingness to sign a written informed consent document.

Exclusion Criteria:

General Exclusion Criteria

• Previously treated breast cancer
• Concurrent malignancy of any type
• Recent breast surgery (within the past 12 months) on the ipsilateral breast as the current breast tumor
• Impaired elimination (as defined as having problems with urination)
• Metallic foreign bodies that would be affected by the MRI magnet, or fear of enclosed spaces likely to make the subject unable to undergo an MRI scan
• Participation in a research study/studies involving radiation exposure within the past 12 months
• Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, major kidney or liver disease, or psychiatric illness/social situations that would limit compliance with study requirements
• Pregnancy
• Currently lactating (either breast feeding or breast pumping)
• Pregnant women are excluded from this study because of the radioactivity of [11C]Martinostat and the resulting risks of teratogenic or abortifacient effects. Because there is an unknown but potential risk for adverse events in nursing infants secondary to administration of [11C]Martinostat, and because lactation may potentially affect the uptake of [11C]Martinostat on PET, breastfeeding women are excluded from the study.

General MR and PET Safety Exclusion Criteria:

• Electrical implants such as cardiac pacemakers or perfusion pumps
• Ferromagnetic implants such as aneurysm clips, surgical clips, prostheses, artificial hearts, valves with steel parts, metal fragments, shrapnel, metallic tattoos anywhere on the body, tattoos near the eye, steel implants, ferromagnetic objects such as jewelry or metal clips in clothing
• Pre-existing medical conditions including a likelihood of developing seizures or claustrophobic reactions, and any greater than normal potential for cardiac arrest
• Inability to lie comfortably on a bed inside a PET camera for 90 minutes as assessed by physical examination and medical history (e.g. back pain, arthritis)
• Pregnancy: A negative serum pregnancy test is required on the day of the PET procedure for female subjects of child-bearing age.
• Body weight of > 250 lbs (weight limit of the MRI table as well as risks to larger patients from MRI elements)