Clinical Research Directory

Inclusion Criteria: * Ability to understand and the willingness to sign a written informed consent. * Karnofsky Performance Status 50% to 100% (Appendix A). * Women 40 years of age or older with a diagnosis of invasive ductal carcinoma * Her-2 3+ or FISH ratio of 2.2 or higher, background gene expression with normal copy number * Only postmenopausal women will be eligible. Subjects will be classified as being postmenopausal if they have had: * No spontaneous menses \> 1 year, or * Bilateral surgical oophorectomy, or * No menses for \< 1 year with FSH and estradiol levels in according to institutional standards * cT1-2N0 on clinical staging (verified to have no suspicious axillary or internal mammary nodes on MRI or ultrasound) * Undergo neoadjuvant chemotherapy with a trastuzumab based regimen prior to surgery and plan for completion of one year of trastuzumab * Patients are required to undergo lumpectomy with sentinel lymph node biopsy * Pathologic review shows no evidence of residual disease in the tumor bed (to also include no evidence of residual DCIS) * Tumor bed should be no larger than 5 cm in size on pathologic review * Fibrotic area of prior tumor located at least 3 mm away from surgical margins * No evidence of treatment related change in the lymph nodes on pathologic review Exclusion Criteria * Diagnosis of inflammatory breast cancer * Previously diagnosed malignancy excluding basal or squamous cell carcinoma of the skin (unless disease-free for 5 years or more) * Diagnosis of metastatic disease