Lapatinib and Radiation Therapy in Treating Patients With Locally Recurrent or Chemotherapy-Refractory Locally Advanced or Metastatic Breast Cancer

DISEASE CHARACTERISTICS:

* Diagnosis of breast cancer meeting 1 of the following criteria:

  * Locally recurrent disease
  * Locally advanced disease AND meets the following criterion:

    * Chemotherapy-refractory disease (achieved \< partial response to ≥ 3 courses of neoadjuvant chemotherapy)
  * Metastatic disease
* Evaluable disease by exam and/or imaging studies

  * Amenable to serial biopsies by skin punch, core biopsy, or fine-needle aspiration
* Unresectable disease after standard neoadjuvant chemotherapy

  * Resectability must be determined by a surgical oncologist prior to treatment
* Stable CNS metastases allowed
* Hormone receptor status not specified

PATIENT CHARACTERISTICS:

* Male or female
* Menopausal status not specified
* Life expectancy \> 12 weeks
* ECOG performance status 0-2
* Not pregnant or nursing
* Negative pregnancy test
* Fertile patients must use effective contraception
* Able to swallow and retain oral medication
* WBC ≥ 3,000/mm³
* ANC ≥ 1,500/mm³
* Platelet count ≥ 100,000/mm³
* Total bilirubin normal
* AST and ALT ≤ 2.5 times upper limit of normal
* Creatinine normal OR creatinine clearance ≥ 60 mL/min
* Cardiac ejection fraction normal by ECHO or MUGA
* No other malignancy within the past 5 years
* No concurrent disease or condition that would preclude study participation
* No ongoing coagulopathy
* No active severe infection

PRIOR CONCURRENT THERAPY:

* See Disease Characteristics
* Recovered from prior therapy
* At least 3 weeks since prior and no other concurrent systemic therapy for breast cancer
* At least 14 days since prior and no concurrent herbal or alternative medicine
* At least 14 days since prior and no concurrent dietary supplement
* At least 14 days since prior CYP3A4 inducers
* At least 7 days since prior CYP3A4 inhibitors
* No antacid within 1 hour before or after study drug administration
* Concurrent bisphosphonate allowed
* No concurrent oral glucocorticosteroid \> 1.5 mg of dexamethasone (or equivalent)