Hormone Therapy With or Without Combination Chemotherapy in Treating Women Who Have Undergone Surgery for Node-Negative Breast Cancer (The TAILORx Trial)

Inclusion Criteria: * Patients with operable histologically confirmed adenocarcinoma of the female breast who have completed primary surgical treatment and meet the following criteria: * ER and/or progesterone receptor (PR)-positive: Estrogen and/or progesterone receptor positive disease (as defined by local pathology laboratory) * Negative axillary nodes: As assessed by a sentinel lymph node biopsy, an axillary dissection, or both, and as defined by the Sixth Edition of the American Joint Committee on Cancer (AJCC) staging criteria * Tumor size 1.1-5.0 cm (or 5 mm-1.0 cm plus unfavorable histological features): * Unfavorable features defined as intermediate or poor nuclear and/or histologic grade, or lymphovascular invasion * NOTE: Definition of tumor size: The tumor size used for determination of eligibility is the pathologic tumor size, which is usually determined by the size of the tumor as measured by inspection of the gross specimen; if the tumor size is measured microscopically and the tumor includes ductal carcinoma in-situ, the measurement should include only the invasive component of the tumor * The tumor must be human epidermal growth factor receptor 2 (Her2)/neu negative by either fluorescent in-situ hybridization (FISH) or immunohistochemistry (e.g. 0 or 1+ by DAKO Herceptest) * The patient and physician must be agreeable to initiate standard chemotherapy and hormonal therapy as adjuvant therapy * A tissue specimen from the primary breast cance…