NSAID Effects on Clinical and Imaging Breast Biomarkers

Inclusion Criteria:

* Eligibility criteria will include: Postmenopausal women with of first incidence of early stage (stages 0 - III) hormone receptor positive breast cancer stabilized on anastrozole therapy for at least 3 months
* Patients must have started on anastrozole and plan to continue on anastrozole therapy for a minimum of 12 months
* Patients must have an unaffected, non-irradiated contralateral breast with a baseline breast density score of \> 25% as measured by standard digital mammography (BIRADs score \> 2) or magnetic resonance imaging (MRI) performed within 12 months of randomization to the study
* A willingness to follow the study protocol, as indicated by provision of informed consent to participate
* A willingness to avoid taking NSAIDs outside of the trial (rare NSAID use for musculoskeletal symptoms excepted)
* Normal renal function as determined by a serum creatinine \< upper limit of normal
* No known contraindication to NSAID use
* Normotensive or controlled blood pressure (\< 140/90) on a single anti-hypertensive medication

Exclusion Criteria:

* Current or anticipated need for daily aspirin or NSAID use including aspirin for cardiovascular protection
* Known intolerance to NSAIDs
* Age \> 75 years
* History of cardiovascular disease including prior myocardial infarction, angina, stroke, or transient ischemic attack (TIA)
* Diabetes requiring drug therapy
* Current smoker
* History of Uncontrolled hypertension
* Blood pressure \> 140/90 at baseline by home monitoring
* History of GI ulcers, chronic GERD, or GI bleeding in the past 5 years
* History of a bleeding diathesis or current anticoagulant therapy
* Daily therapy with H2 blockers or protein pump inhibitors
* History of claustrophobia
* Have electrically, magnetically, or mechanically activated implants including cardiac pacemaker, cochlear implants, magnetic surgical clips or prostheses.