Testing an Active Form of Tamoxifen (4-hydroxytamoxifen) Delivered Through the Breast Skin to Control Ductal Carcinoma in Situ (DCIS) of the Breast

Inclusion Criteria:

Screen-detected, estrogen receptor (ER) positive DCIS of the breast proven on core needle biopsy, defined as 10% positive cells; the presence of a focus suspicious for microinvasion will be allowed; the size of the DCIS in the core biopsy sample must total 5 mm (multiple cores can be summed) and must be estimated on the deepest step section (if step sections are taken)
Eastern Cooperative Oncology Group (ECOG) performance status =< 1 (Karnofsky >= 70%)
Participants must have acceptable organ and marrow function as defined below:

Baseline lab parameters are not standard of care for initiation of tamoxifen therapy; a minimal panel will therefore be appropriate.

Leukocytes >= 3,000/microliter
Absolute neutrophil count >= 1,500/microliter
Platelets >= 100,000/microliter
Total bilirubin within "≤1.5 x institutional upper limit of normal (ULN)institutional limits
Aspartate aminotransferase (AST) (serum glutamic-oxaloacetic transaminase [SGOT])/alanine aminotransferase (ALT) (serum glutamate pyruvate transaminase [SGPT]) =< 1.5 x institutional upper limit of normal (ULN)
Creatinine within "≤1.5 x institutional upper limit of normal (ULN) institutional limits
Women of childbearing potential and their male partners must agree to use TWO effective forms of birth control (abstinence is not an allowed method) prior to study entry and for the duration of study participation, and for two months following the last dose of study medications; effective birth control methods are: copper IUD [intrauterine device], diaphragm/cervical cap/shield, spermicide, contraceptive sponge, condoms; women of childbearing potential must have a negative urine pregnancy test within seven days before starting study medications; should a woman become pregnant or suspect she is pregnant while participating in this study, she should inform her study physician immediately
Willingness to avoid exposing breast skin to natural or artificial sunlight (i.e. tanning beds) for the duration of the study
Ability to understand and the willingness to sign a written informed consent document

Exclusion Criteria:

DCIS presentation as a palpable mass
Exogenous sex steroid use within 4 weeks prior to core needle biopsy
Prior ipsilateral breast cancer radiotherapy will be excluded; prior contralateral breast cancer therapy within 2 years will also be excluded
Skin lesions on the breast that disrupt the stratum corneum (eg eczema, ulceration)
History of endometrial neoplasia
History of thromboembolic disease (history of varicose veins and superficial phlebitis is allowed)
Current smokers
Current users of potent inhibitors of tamoxifen metabolism must be able to discontinue their use and switch to an alternative medication for the duration of participation, under the advice of their physician; if the physician feels that an alternative medication is not appropriate for the subject and the current medication is medically necessary, the subject will not be eligible; the drugs are listed below; many of these are not in clinical use at the moment; bupropion, celecoxib, chlorpheniramine, chlorpromazine, cimetidine, citalopram, clemastine, clomipramine, clozapine, cocaine, delavirdine, desipramine, diphenhydramine, doxepin, duloxetine, escitalopram, fluoxetine, haloperidol, halofantrine, hydroxyzine, imipramine, isoniazid, ketoconazole, methadone, methimazole, mibefradil, miconazole, nicardipine, paroxetine, pergolide, perphenazine, pioglitazone, pyrimethamine, quinidine, quinine, ranitidine, ritonavir, ropinirole, sertraline, terbinafine, thioridazine, ticlopidine, tranylcypromine, trazodone, tripelennamine
Prior use of SERMS or AIs including tamoxifen, raloxifene, anastrozole, letrozole, or exemestane for prevention or therapy within 5 years
Participants may not be receiving any other investigational agents within 30 days of enrollment or during this study
History of allergic reactions attributed to tamoxifen or compounds of similar chemical or biologic composition
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
Pregnant women are excluded from this study; breastfeeding should be discontinued by nursing mothers who agree to participate in the study
Men are excluded from this study since DCIS of the breast is exceedingly rare in men, and there are no data regarding skin penetration of 4-OHT though male chest wall skin (which is thicker and hairier than female chest wall skin)