Lapatinib in Treating Women With Ductal Carcinoma In Situ of the Breast

Inclusion Criteria:

• Pre- or postmenopausal
• ECOG performance status 0-2
• WBC > 4,000/mm^3
• Platelet count > 100,000/mm^3
• Hematocrit > 30%
• BUN or serum creatinine =< 1.5 times upper limit of normal (ULN)
• Total bilirubin =< 1.5 times ULN
• Albumin =< 1.5 times ULN
• ALT and AST =< 1.5 times ULN
• Alkaline phosphatase =< 1.5 times ULN
• LVEF normal by MUGA scan or cardiac ultrasound
• Not pregnant or nursing
• Fertile patients must use effective contraception during and for 1 month after completion of study treatment
• Negative pregnancy test
• At least 7 days since prior and no concurrent inhibitors of CYP3A4
• No antibiotics: clarithromycin, erythromycin, troleandomycin
• No HIV drugs: antiretrovirals (delavirdine), protease inhibitors (ritonavir, indinavir, saquinavir, nelfinavir, amprenavir, lopinavir)
• No antifungals: itraconazole, ketoconazole, voriconazole, fluconazole (doses up to 150 mg/day are permitted)
• No antidepressants: nefazodone, fluvoxamine
• No calcium channel blockers: verapamil, diltiazem
• No gastrointestinal inhibitors of CYP3A4: cimetidine, aprepitant, ranitidine, nizatidine, famotidine, proton pump inhibitors (omeprazole, esomeprazole, rabeprazole, pantoprazole, lansoprazole)
• No 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
• No glucocorticoids: dexamethasone or dexamethasone equivalent dose > 1.5 mg/day
• No anticonvulsants: phenytoin, carbamazepine, phenobarbital
• No HIV drugs: efavirenz, nevirapine
• No antibiotics: rifampin (rifampicin), rifabutin, rifapentine
• At least 6 months since prior and no concurrent amiodarone
• No miscellaneous inducers of CYP3A4: Hypericum perforatum (St. John's wort), modafinil

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
• Tamoxifen, raloxifene, letrozole, anastrozole, or exemestane in the past 3 months
• Concurrent tamoxifen, raloxifene, or aromatase inhibitors (letrozole, anastrozole, exemestane)
• Concurrent anticoagulation therapy (e.g., warfarin)
• Concurrent participation in another study of an investigational drug
• 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 anti-arrhythmics, beta blockers, or other medications that may lead to QT prolongation
• Prior cumulative dose of anthracycline therapy greater than 500 mg/m^2