Management of axilla in breast cancer: the past, present and the future

The role of surgery in treatment of breast cancer has evolved substantially during the last century where radical surgery has gradually been replaced by more conservative approaches. Similarly, surgical treatment of the axilla has changed rapidly especially over last three decades. This is mostly as a result of improvements in understanding of disease behaviour and advances in systemic therapy. Axillary surgery has the dual uses of removing the disease from the axilla and providing information for prognostication which help guide adjuvant therapy. However, surgery to the axilla is associated with substantial morbidly including lymphedema and shoulder stiffness. Hence, less radical approaches for the treatment of the axilla have been of interest. The traditional gold standard of axillary lymph node dissection was challenged by many clinical trials. As result sentinel lymph node biopsy was introduced as an alternative for patients with clinically negative axillae which later became the standard of care for such patients. Subsequent studies proved the safety of omitting completion axillary dissection or replacing with radiotherapy for selected patients with minimal sentinel lymph node involvement. The application of sentinel lymph node biopsy for axillary staging after neoadjuvant chemotherapy has become an area of clinical interest. However, sentinel lymph node biopsy in node-positive patients who become node negative after neoadjuvant chemotherapy is controversial at present due to the relatively high false-negative rate. This however, is improved by careful patient selection combined with some minor changes to the surgical technique of sentinel lymph node biopsy. Novel techniques for lymphatic mapping have shown promising results which further simplify the procedure while improving the accuracy. Axillary reverse mapping, a technique to preserve lymph nodes draining the arm during axillary surgery for breast cancer has been described recently which has further reduced surgical morbidity. The omission of axillary surgery in selected patients with an acceptably low risk of nodal metastasis has gained increasing research interest in the recent past. Furthermore, advances in treatment and newer prognostication techniques have reduced the dependence on axillary nodal status on adjuvant therapy decision-making. This has led to several ongoing clinical trials which will assess the feasibility of avoiding sentinel lymph node biopsy altogether in selected groups of patients without compromising outcomes.