Conjugated Estrogens/Bazedoxifene in Treating Patients with Ductal Carcinoma in Situ Undergoing Surgery

Inclusion Criteria

• Women must have newly diagnosed histologically confirmed ER positive (+) DCIS scheduled to undergo surgical therapy; the pathology report (signed pathology report from attending pathologist) from each individual institution will be used to determine eligibility; extent of DCIS in imaging per site institutional standard * Note: After the patient has completed the study and the slides have been sent to Northwestern University (NU), our pathologists will review the slides to confirm the diagnosis * Note: DCIS suspicious for micro invasion is eligible on core biopsy * Note: Women presenting with bilateral DCIS are eligible but if both right and left DCIS are ER+, we will only accept tissue from the side with the largest area of DCIS based on imaging and pathology criteria
• DCIS must be >= 1 cm based on extent of calcifications, presence of a mass on ultrasound OR enhancement on magnetic resonance imaging (MRI) OR
• DCIS must be >= 5 mm of DCIS on one single core; can be < 5 mm if DCIS is identified on multiple cores (at least 2 cores)
• Women presenting after excision with positive margins are eligible; Ki-67, cyclooxygenase 2 (Cox-2), cyclin-dependent kinase inhibitor 2A (P-16), expression in immediately adjacent tissue is similar to what is found in DCIS * Note: Positive margins are defined as DCIS present at the inked margin or DCIS < 1 mm from the margin
• Women must be postmenopausal (defined as no menstrual cycle for 12 months or surgical history of bilateral salpingoopherectomy); postmenopausal women of all races and ethnic groups are eligible to participate for this trial; men are not eligible * Note: women who have had a hysterectomy without a bilateral salpingoopherectomy may still be pre-menopausal; confirmation of post-menopausal status is required for these patients and will be measured by testing levels of estradiol, progesterone and follicle stimulating hormone (FSH) (lab ranges per institutional standards); in addition, confirmation of postmenopausal status may be performed in any patient with unclear menopausal status per treating physician discretion
• Eastern Cooperative Oncology Group (ECOG) performance status =< 2 (Karnofsky >= 60%)
• Leukocytes >= 3,000/mcL
• Platelets >= 100,000/mcL
• Hemoglobin >= 9 g/dl
• Total bilirubin =< 1.5 x upper limit of normal (ULN)
• Aspartate aminotransferase (AST) (serum glutamic oxaloacetic transaminase [SGOT]) and alanine aminotransferase (ALT) (serum glutamate pyruvate [SGPT]) =< 2.5 x institutional upper limit of normal
• Serum creatinine =< 1.5 x ULN OR creatinine clearance >= 60 mL/min/1.73 m^2 for patients with creatinine levels above institutional normal (calculated with the Cockcroft-Gault Equation in EPIC)
• Patients ability to swallow oral medication
• Ability to understand and the willingness to sign a written informed consent document and comply with all procedures

Exclusion Criteria

• Patients who are receiving any other investigational agents; a minimum of 4 weeks wash-out period is required for eligibility; please contact principal investigator, Dr. Swati Kulkarni for further clarification
• Patients with a “currently active” second malignancy other than non-melanoma skin cancers; patients are not considered to have a “currently active” malignancy if they have completed therapy and are free of disease for >= 3 years
• History of allergic reactions/hypersensitivity attributed to compounds of similar chemical or biologic composition to CE/BZA; (I.e. same class of drug as CE/BZA)
• Current hormone replacement therapy (HRT), selective estrogen receptor modulator (SERM) or aromatase inhibitor (AI) use; if yes, the wash-out period is 30 days before diagnostic core needle biopsy * Note: local therapy (i.e. estrogen cream) will be permitted due to low systemic absorption of estrogen * Note: if patient is registered prior to completed washout, diagnostic core needle biopsy date will need to be provided
• Confirmed current or past diagnosis of invasive breast cancer
• History of gynecologic malignancy that is estrogen dependent
• Patients with recurrent ipsilateral DCIS
• Active deep venous thrombosis, pulmonary embolism, retinal vascular thrombosis, and any arterial thrombosis including stroke and myocardial infarction or history of these conditions
• Known protein C, protein S, or anti-thrombin deficiency or other known thrombophilic disorders
• Unexplained/undiagnosed abnormal uterine bleeding (concern for undiagnosed endometrial cancer)
• Women who are pregnant or lactating, if this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, the patient should be apprised of the potential hazard to a fetus
• Patients receiving any medications or substances that are strong inhibitors or inducers of CYP3A4 and UGT are ineligible; the wash out period for such drugs is a minimum of 7 days or 5 half-lives whichever is shorter * Note: If a medication is incorrectly documented as prohibited in this protocol, documentation from the site pharmacist to the contrary will be acceptable for the purposes of registration
• Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations that would limit compliance with study requirements