Prognostic factors for breast cancer beyond stage at diagnosis and tumor characteristics have not been well studied. Of special interest are lifestyle factors that can be modified by women after diagnosis to increase disease-free survival. Green tea is rich in polyphenols consisting primarily of epicatechins, epigallocatechin, epicatechin gallate, and epigallocatechin gallate (EGCG). The investigators hypothesize that there will be a reduction in proliferation and/or an increase in apoptosis in association with short-term EGCG treatment.

Inclusion Criteria:

• Postmenopausal (at least 2 years since last menstrual period) or age 55 or older if prior hysterectomy
• Non-current (not with past 6 months) user of menopausal hormones
• Mammographic abnormality consistent with any type of incident breast cancer necessitating a diagnostic biopsy (BIRAD IV(b), (c) or V) will be sufficient to draw baseline LFT and complete screening questionnaire. Unless the biopsy confirms incident breast cancer, such subjects will not be included in further research interventions and they will not serve as EGCG treated or control subjects.
• Diagnosed with incident breast cancer on the diagnostic biopsy is required for inclusion in the EGCG or control treatment groups.
• Non-green tea drinker (less than monthly) - this criteria does not apply to black tea or herbal tea
• Provided written informed consent

Exclusion Criteria:

• Green tea drinker (once per month or more)
• History of breast cancer or other cancer including a prior diagnosis of any type of incident breast cancer.
• Known allergy to tea
• Abnormal liver enzymes (plus or minus 10% of the normal ranges).