Original principal investigator departed institution and concluded the study upon departure.

The purpose of this study is to look at the effects that the study drug (OPC) has on AGE levels in patients with ER+ metastatic breast cancer.

AGEs are a type of metabolite, or substance, found in the food. The AGE content in food is determined by the types of food you eat and also how you prepare your food. The researchers helping conduct this study have found a potential link between AGE levels and cancer. The purpose of this study is to see if certain drug (OPC) has an effect on the AGE levels in your blood and to see if those AGE levels have an effect on your cancer.

Inclusion Criteria:

• Must have ER+ breast cancer
• Metastatic disease; protocol does allow for bone-only disease
• Must be receiving endocrine therapy
• Must have completed at last 2 months of current endocrine therapy prior to registration
• Must have adequate hematologic, renal and hepatic function
• Prior/concurrent radiation therapy is allowed
• Prior chemotherapy is allowed, but last dose must have been at least 2 months prior to enrollment
• May have diabetes, but must not be taking metformin
• Must be able to swallow and retain oral medication
• Performance status of 0-2
• Treated stable brain metastases are allowed, as long as patient does not require steroids or anti-seizure medications
• Must be informed of the investigational nature of this study and must have the ability to sign informed consent.

Exclusion Criteria:

• Known allergy to grapes or grape seed
• More than two prior endocrine therapy regimens for the treatment of metastatic ER+ breast cancer.
• Concurrent use of restricted agents outlined in section 4.5.
• History of alcohol abuse within 2 years of registration.