Management of the axilla in early breast cancer (EBC) patients has dramatically evolved in recent years from more radical to increasingly conservative approaches. Classically, the EBC patients with a clinically positive axilla are offered axillary lymph node dissection (ALND) and those with a clinically negative axilla (cN0) are offered sentinel lymph node (SLN) biopsy, which obviates the complications related to ALND and provides adequate surgical staging and comparable locoregional control and survival. The need for performing ALND when the SLN is positive and contemporary adjuvant treatment is delivered has been questioned in recent years. On the other hand, ongoing trials are testing whether node-positive patients can be spared chemotherapy, based on intrinsic primary tumor biology. Because the integration of novel surgical management and tumor biology is needed, this article provides an overview of the current challenges that a more detailed knowledge of tumor biology has brought to EBC staging and treatment. We propose that breast cancer oncologists (surgeons, radiation therapists, and medical oncologists) should focus their efforts on offering therapy tailored to each patient's needs in such a way that no matter which treatment is used, no overtreatment occurs.