RakSutkaBreast cancer: the biology, the detection, and how the treatment changed.

SurgeryEntry 04.4

The Axilla

What was established

The lymph nodes tucked into the armpit became a surgical battleground of their own.

An anatomical teaching model on a stand in a plain room, side light
Consequences borne by the armHow much of the axilla to clear was its own long argument, with lymphoedema on the other side of it.

The argument under the arm

For most of the twentieth century, clearing the axilla — the armpit — was taken as an article of faith. Halsted's operation removed the pectoral muscles and swept every identifiable lymph node from the armpit as a single block, the logic being that cancer moved through the lymphatic system in an orderly progression and that anything less left disease behind. Node clearance was not incidental; it was, under Halsted's theory of spread, the point.

The consequences for the arm were severe. Cutting the lymphatic channels draining the limb causes lymphoedema — a chronic, sometimes disabling swelling — in a significant proportion of patients. Nerve damage to the axilla can produce pain, numbness and weakness across the upper arm and chest wall. These were accepted as the cost of thoroughness.

Lifted out of the flow

Chronology

  1. Mid-twentieth centuryaxillary clearance standard with radical mastectomy
  2. 1970sNSABP B-04 finds no survival benefit attributable to extent of axillary surgery
  3. 1990ssentinel node biopsy developed and validated in prospective trials
  4. 2011ACOSOG Z0011 trial published, limiting axillary surgery further in selected patients

What challenged that acceptance was trial evidence. The NSABP B-04 trial, reported by Bernard Fisher and colleagues from Pittsburgh, compared radical mastectomy against less extensive operations and found no survival difference attributable to the extent of axillary surgery. If clearing every node did not improve survival, the rationale for the injury it caused was weakened substantially.

The field then moved toward sampling rather than clearance. Sentinel node biopsy — identifying and removing only the first node or nodes that drain a tumour, then examining them — was developed through the 1990s. If the sentinel node is free of cancer, the reasoning holds that the remaining nodes are very likely clear as well, and the axilla can be left alone. A series of prospective trials confirmed that this approach, in appropriate patients, did not increase the rate of regional recurrence and sharply reduced the rate of lymphoedema compared with full axillary clearance.

A modern operating theatre lit and prepared with instruments laid out, unoccupied
Settled by trials, not argumentRemoving less was resisted for years, then shown to give the same survival.See Conserving surgery

The American College of Surgeons Oncology Group Z0011 trial, published in 2011, pushed further: it found no survival detriment when certain patients with positive sentinel nodes had no further axillary surgery at all. The armpit, like the breast itself, turned out to require less intervention than the radical tradition had assumed.

Elsewhere in surgery

  • The radical mastectomyWilliam Halsted formalised the operation in the 1890s and it remained standard for roughly eighty years.
  • Halsted's theory of spreadThe operation followed from a theory about how the disease travelled, and when the theory turned out to be wrong the operation went with it.
  • Conserving surgeryRemoving less tissue was resisted for a long time and then shown to give the same result, which took trials rather than argument.