Topical Afimoxifene in Treating Patients With Breast Cancer Who Have Undergone Radiation Therapy on One Breast

Inclusion Criteria:

• Patients must have received prior unilateral breast radiotherapy (RT) for ductalbreast carcinoma in situ (DCIS) or invasive cancer (>= 12 weeks after the end ofRT), and have an intact unradiated (non-RT) breast.

• Eastern Cooperative Oncology Group (ECOG) performance status =< 1 (Karnofsky >= 70%).

• A prior history of malignancy is allowed, as long as the patient is considered tohave ?no evaluable disease? and cancer treatment has been completed.

• Females of child-bearing potential (FOCBP) and male partners of female participantsmust agree to use TWO effective forms of birth control (abstinence is not an allowedmethod) prior to study entry and for the duration of study participation, and fortwo months following the last dose of study medications. Effective birth controlmethods are: copper IUD (intrauterine device), diaphragm/cervical cap/shield,spermicide, contraceptive sponge, condoms. Should a female patient become pregnantor suspect she is pregnant while participating in this study, she should inform hertreating physician immediately.

• NOTE: A FOCBP is any woman (regardless of sexual orientation, having undergonea tubal ligation, or remaining celibate by choice) who meets the followingcriteria:

• Has not undergone a hysterectomy or bilateral oophorectomy

• Has had menses at any time in the preceding 12 consecutive months (andtherefore has not been naturally postmenopausal for > 12 months).

• FOCBP must have a negative urine pregnancy test within 7 days prior to registrationon study.

• Willingness to avoid exposing breast skin to natural or artificial sunlight (i.e.tanning beds) for the duration of the study drug use.

• Patients must have the ability to understand and the willingness to sign a writteninformed consent prior to registration on study.

Exclusion Criteria:

• Patients receiving any other investigational agents within 30 days of registrationare not eligible.

• Patients currently using oral selective estrogen receptor modulators (SERMS) (tamoxifen, raloxifene, bazedoxifene) are not eligible.

• Note: Prior or current endocrine therapy other than SERMs are allowed.

• Patients who have a history of allergic reactions attributed to compounds of similarchemical or biologic composition afimoxifene (4-OHT) are not eligible.

• Patients who have an uncontrolled intercurrent illness including, but not limited toany of the following, are not eligible:

• Hypertension that is not controlled on medication

• Ongoing or active infection requiring systemic treatment

• Symptomatic congestive heart failure

• Unstable angina pectoris

• Cardiac arrhythmia

• Psychiatric illness/social situations that would limit compliance with studyrequirements

• Any other illness or condition that the treating investigator feels wouldinterfere with study compliance or would compromise the patient?s safety orstudy endpoints.

• Female patients who are pregnant or nursing are not eligible.

• Patients with prior bilateral breast cancer radiotherapy or radiotherapy forlymphoma will be excluded.

• Patients with skin lesions on the breast that disrupt the stratum corneum (e.g.eczema, ulceration) are not eligible.

• Patients with a history of endometrial neoplasia are not eligible.

• Patients with a history of thromboembolic disease are not eligible.

• Note: history of varicose veins and superficial phlebitis is allowed.

• Patients who are undergoing active treatment for any malignancy will be excluded.

• Male patients are excluded from this study since there are no data regarding skinpenetration of 4-OHT though male chest wall skin (which is thicker and hairier thanfemale chest wall skin).