Doxorubicin and Cyclophosphamide Followed By Trastuzumab, Paclitaxel, and Lapatinib in Treating Patients With Early-Stage HER2-Positive Breast Cancer That Has Been Removed By Surgery

DISEASE CHARACTERISTICS:

* Histologically confirmed diagnosis of early-stage breast cancer

  * HER2 positive by immunohistochemistry (IHC) (3+) or fluorescent in situ hybridization (FISH)

    * Ductal carcinoma in situ (DCIS) components should not be counted in the determination of degree of IHC staining or FISH amplification
* No locally advanced tumors (i.e., T4) at diagnosis, including the following:

  * Tumors fixed to chest wall
  * Peau d'orange
  * Skin ulcerations or nodules
  * Clinical inflammatory changes (e.g., diffuse brawny cutaneous induration with an erysipeloid edge)
* Has undergone mastectomy or lumpectomy with axillary node or sentinel node dissection within the past 84 days

  * Patients who have undergone a mastectomy must meet the following criteria:

    * No evidence of gross or microscopic tumor (i.e., invasive DCIS) at the surgical resection margins noted in final surgery or pathology reports

      * Patients with close margins are eligible
    * Radiation therapy is required for 4 or more positive lymph nodes and must be started after completion of chemotherapy
  * Patients who have undergone a lumpectomy with axillary node or sentinel node dissection must meet the following criteria:

    * No evidence of invasive cancer or DCIS at the surgical resection margins
    * No gross residual adenopathy
    * Planning to undergo radiation therapy to the breast with or without regional lymphatics after completion of chemotherapy
* No active hepatic or biliary disease

  * Patients with liver metastases, stable chronic liver disease, Gilbert's syndrome, or asymptomatic gallstones are eligible
* Hormone receptor status:

  * Estrogen receptor and progesterone receptor status known

PATIENT CHARACTERISTICS:

* Male or female
* Menopausal status not specified
* ECOG performance status 0-2
* Absolute neutrophil count ≥ 1,500/mm³
* Platelet count ≥ 100,000/mm³
* Hemoglobin ≥ 10.0 g/dL
* Bilirubin ≤ 1.5 times upper limit of normal (ULN)
* AST and ALT ≤ 2.5 times ULN
* Alkaline phosphatase ≤ 2.5 times ULN
* Creatinine normal OR creatinine clearance ≥ 60 mL/min
* LVEF ≥ 50% by MUGA scan or echocardiogram
* Able to complete questionnaire(s) by themselves or with assistance
* Able and willing to provide blood and tissue samples
* No known sensitivity to benzyl alcohol
* No sensory neuropathy ≥ grade 2
* No active cardiac disease, including any of the following:

  * Myocardial infarction within the past 6 months
  * Prior or concurrent congestive heart failure
  * Prior or concurrent arrhythmia or cardiac valvular disease requiring medications or that is clinically significant
  * Uncontrolled hypertension, defined as diastolic blood pressure (BP) \>100 mm Hg or systolic BP \> 200 mm Hg on 2 separate occasions ≥ 14 days apart
  * Clinically significant pericardial effusion
  * Prior or concurrent uncontrolled or symptomatic angina
  * Other cardiac condition that, in the opinion of the treating physician, would put the patient at hazardous risk
* No history of allergic reactions attributed to compounds of similar chemical or biologic composition as lapatinib ditosylate
* No uncontrolled intercurrent illness including, but not limited to, the following:

  * Ongoing or active infection
  * Psychiatric illness or social situations that would preclude study compliance
* Able to swallow and retain oral medication

  * No history of gastrointestinal (GI) disease resulting in an inability to take oral medication, including any of the following:

    * Malabsorption syndrome
    * Requirement for IV alimentation
    * Prior surgical procedures affecting absorption
    * Uncontrolled inflammatory GI disease (e.g., Crohn's disease or ulcerative colitis)
* Not pregnant or nursing
* Negative pregnancy test
* Fertile patients must use effective contraception during and for 6 months after completion of study treatment

PRIOR CONCURRENT THERAPY:

* See Disease Characteristics
* No prior chemotherapy, radiation therapy, immunotherapy, or biotherapy for breast cancer
* No primary breast radiation therapy as part of breast-conserving treatment
* No prior anthracycline or taxane therapy for any malignancy
* No prior epidermal growth factor receptor-targeting therapies (e.g., gefitinib, cetuximab, erlotinib hydrochloride, rituximab, trastuzumab \[Herceptin®\], lapatinib ditosylate, panitumumab, or nimotuzumab)
* At least 14 days since prior and no concurrent CYP3A4 inducers, including the following:

  * Rifamycin-class antibiotics (e.g., rifampin, rifabutin, or rifapentine)
  * Anticonvulsants (e.g., phenytoin, carbamazepine, or barbiturates \[e.g., phenobarbital\])
  * Antiretrovirals (e.g., efavirenz or nevirapine)
  * Glucocorticoids (e.g., oral cortisone, hydrocortisone, prednisone, methylprednisolone, or dexamethasone)

    * Daily oral dexamethasone ≤ 1.5 mg (or equivalent) allowed
  * Modafinil
  * Hypericum perforatum (St. John's wort)
* At least 7 days since prior and no concurrent CYP3A4 inhibitors, including the following:

  * Antibiotics (e.g., clarithromycin, erythromycin, or troleandomycin)
  * Antifungals (e.g., itraconazole, ketoconazole, fluconazole \[\> 150 mg daily\], or voriconazole)
  * Antiretrovirals and protease inhibitors (e.g., delaviridine, nelfinavir, amprenavir, ritonavir, indinavir, saquinavir, or lopinavir)
  * Calcium channel blockers (e.g., verapamil or diltiazem)
  * Antidepressants (e.g., nefazodone or fluvoxamine)
  * Gastrointestinal agents (e.g., cimetidine or aprepitant)
  * Grapefruit and grapefruit juice
* At least 6 months since prior and no concurrent amiodarone
* No herbal or alternative medicines or supplements ≥ 14 days before, during, and for 30 days after completion of study treatment
* No concurrent hormonal agents (e.g., birth control pills, ovarian hormonal replacement therapy, or raloxifene)

  * Adjuvant hormonal agents (e.g., tamoxifen, aromatase inhibitors) allowed after completion of chemotherapy as part of treatment for breast cancer
* No concurrent antiretroviral therapy for HIV-positive patients
* No concurrent digitalis or beta-blockers for congestive heart failure
* No concurrent arrhythmia or angina pectoris medication
* No other concurrent investigational agents or anticancer therapies, including cytotoxic agents or immunotherapy