DISEASE CHARACTERISTICS: - Diagnosis of ductal carcinoma in situ (DCIS) made by core needle biopsy - DCIS cells must have high expression of erbB2 (3+ by IHC staining or amplification by FISH), and/or detectable expression of EGFR (1+ or more by IHC staining) - Hormone receptor status not specified PATIENT CHARACTERISTICS: Inclusion criteria: - Female - Pre- or postmenopausal - ECOG performance status 0-2 - WBC > 4,000/mm³ - Platelet count > 100,000/mm³ - Hematocrit > 30% - BUN or serum creatinine ≤ 1.5 times upper limit of normal (ULN) - Total bilirubin ≤ 1.5 times ULN - ALT and AST ≤ 1.5 times ULN - Alkaline phosphatase ≤ 1.5 times ULN - Albumin ≤ 1.5 times ULN - LVEF normal by MUGA scan or cardiac ultrasound - Not pregnant or nursing - Negative pregnancy test - Fertile patients must use effective contraception during and for 1 month after completion of study treatment - Willing to refrain from donating blood to others during the study Exclusion criteria: - Other active cancer or a prior history of malignancies other than breast cancer, skin cancer (basal or squamous cell carcinoma), cervical cancer in situ, or early bladder cancer (preinvasive transitional cell carcinoma of the bladder) within the past five years - Severe underlying chronic illness or disease, such as uncontrolled diabetes - Known congestive heart disease or previous myocardial infarction - Hypokalemia or hypomagnesemia unless these conditions are corrected to within normal limits before starting study drug - Congenital long QT syndrome or baseline QTcF intervals > 480 msec on EKG PRIOR CONCURRENT THERAPY: Inclusion criteria: - See Disease Characteristics - At least 7 days since prior and no concurrent inhibitors of CYP3A4: - Antibiotics: clarithromycin, erythromycin, troleandomycin - HIV drugs: antiretrovirals (delavirdine), protease inhibitors (ritonavir, indinavir, saquinavir, nelfinavir, amprenavir, lopinavir) - Antifungals: itraconazole, ketoconazole, voriconazole, fluconazole (doses up to 150 mg/day are permitted) - Antidepressants: nefazodone, fluvoxamine - Calcium channel blockers: verapamil, diltiazem - Gastrointestinal : cimetidine, aprepitant, ranitidine, nizatidine, famotidine, proton pump inhibitors (omeprazole, esomeprazole, rabeprazole, pantoprazole, lansoprazole) - Grapefruit or its juice - At least 7 days since prior and no concurrent gastric pH modifiers (antacids [prohibited within 1 hour before and after dosing]) - At least 14 days since prior and no concurrent inducers of CYP3A4: - Glucocorticoids: dexamethasone or dexamethasone equivalent dose > 1.5 mg/day - Anticonvulsants: phenytoin, carbamazepine, phenobarbital - HIV drugs: efavirenz, nevirapine - Antibiotics: rifampin (rifampicin), rifabutin, rifapentine - Miscellaneous: Hypericum perforatum (St. John's wort), modafinil - At least 6 months since prior and no concurrent amiodarone Exclusion criteria: - Tamoxifen, raloxifene, letrozole, anastrozole, or exemestane in the past 3 months - Chemotherapy, biologic therapy (e.g., trastuzumab [Herceptin®]), or breast radiotherapy to the breast currently affected by DCIS within the past year for patients with breast cancer, nonmelanoma skin cancer, carcinoma in situ of the cervix, or early bladder cancer - Concurrent tamoxifen, raloxifene, or aromatase inhibitors (letrozole, anastrozole, exemestane) - Concurrent anticoagulation therapy (e.g., warfarin) - Concurrent participation in another study of an investigational drug - Concurrent anti-arrhythmics, beta blockers, or other medications that may lead to QT prolongation - Prior cumulative dose of anthracycline therapy greater than 500 mg/m²