The technique of sentinel lymph node dissection is validated by a number of authors using a variety of techniques (74,75). The information obtained from sentinel lymph node dissection appears to be equivalent to that of axillary lymph node dissection. One prospective study demonstrated that in node-negative patients undergoing only sentinel lymph node dissection, the recurrence rate in the axilla was zero at a median follow-up of 39 months (76). Overall survival for patients who undergo sentinel lymph node dissection without axillary dissection appears to be excellent. In a randomized controlled trial, Veronesi et al. showed that the long-term breast cancer–related event-free survival among patients in the sentinel node biopsy arm (89.9%) was similar to that in the axillary lymph node dissection arm (88.8%), affirming not only that sentinel lymph node biopsy is as good as complete axillary dissection at staging the axilla, but that it is as safe as the once standard method of complete axillary dissection (77). Sentinel node biopsy alone without complete axillary lymph node dissection may have value in patients with micrometastatic and macrometastatic disease given low recurrence rates after sentinel lymph node biopsy. In a randomized controlled trial, in patients with hematoxylin and eosin (H&E) positive sentinel lymph nodes, there was no statistically significant difference in overall survival between patients randomized to complete axillary lymph node dissection and sentinel lymph node biopsy alone (78). The degree of accuracy in predicting axillary metastasis, combined with its very low morbidity rate, makes sentinel lymph node dissection the preferred procedure for staging the axilla in breast cancer.
Adjuvant Systemic For many patients, local and regional control of breast cancer is achieved with a combination Therapy of surgery and radiation therapy. About 90% of patients will never experience an in-breast recurrence; these patients may develop metastatic disease. The goal of adjuvant systemic therapy is to eliminate occult metastases during the early postoperative period and thus reduce the risk of local and distant recurrence (79).
Adjuvant systemic therapy will prolong survival in selected breast cancer patients. In patients with favorable tumors and a low risk of recurrence and subsequent death, such as those with node-negative cancers smaller than 1 cm and favorable biology, this benefit is small and may not justify the risks of systemic therapy. Adjuvant systemic therapy reduces the odds of death by 25% per year in both node-negative and node-positive patients (80). Because this risk reduction is relatively constant, patients with favorable, node-negative disease have a much smaller absolute benefit compared with patients who have higher-risk, node-positive disease and/or patients with unfavorable biologic markers such as patients with triple negative disease or Her-2/neu positive disease. For patients with node-negative disease, the absolute benefit may be minimal versus 10% to 20% for those with nodal involvement.