Lapatinib Ditosylate and Radiation Therapy in Treating Patients With Locally Advanced or Locally Recurrent Breast Cancer

Inclusion Criteria:

* Patients with histologically or cytologically confirmed locally advanced breast cancer that is refractory to chemotherapy or other therapeutic agents or with a history of breast cancer with new evidence of a local recurrence (defined as a chest wall or breast recurrence and/or nodal recurrence); the diagnosis will be made based on clinical and pathologic features
* Patients must be \>18 years of age.
* Karnofsky Performance Status (KPS) score \> 70
* Patts must have normal organ function as defined below:

* total bilirubin \< 1.5 x institutional upper limit of normal
* AST(SGOT)/ALT(SGPT) \< 2.5 x institutional upper limit of normal
* creatinine \< 1.5 x institutional upper limit of normal
* Patients must have left-ventricular ejection fraction \> 50% at baseline.

Exclusion Criteria:

* Patients who have contraindications to radiotherapy, such as scleroderma, dermatomyositis, or severe cutaneous manifestations of systemic lupus erythematosus (SLE)
* History of allergic reactions attributed to compounds of similar chemical or biologic composition to lapatinib
* Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, or psychiatric illness/social situations that would limit compliance with study requirements
* Women who are pregnant or lactating, as well as women of child-bearing potential who are unwilling or unable to use an acceptable method of birth control to avoid pregnancy for the duration of the study