The surgical management of breast cancer has undergone radical change in the last 40 years. While it used to be standard practice to perform mastectomies, new breast-conserving procedures have been developed which have been shown to be as effective as mastectomy in some cases. Mr Udi Chetty reviews the evidence and the criteria for breast-conserving surgery and mastectomy.

The surgical management of breast cancer has undergone considerable change over the last 40 years. The gold standard was formerly the Halsted radical mastectomy, in which the whole of the breast was removed with the pectoralis muscles and axillary contents. The need for this mutilating surgery has been challenged. McWhirter, in Edinburgh, showed that a simple mastectomy plus radiotherapy was as effective as a radical mastectomy. In the 1970s, three groups in Europe and the US set up randomised clinical trials to test the efficacy of breast-conserving surgery (removing the tumour combined with radiotherapy) compared with a radical mastectomy. The long-term results from two of these studies have been published recently in the New England Journal of Medicine (NEJM). Both of these studies show that, after 20 years of follow-up, breast-conserving procedures gave results equivalent to radical mastectomy in terms of death from breast cancer and overall survival.

Does this mean that there is no place for mastectomy in the treatment of breast cancer? Unfortunately not. In both trials patients were selected for entry by the size of the tumour, clinical node status and site of the tumour.

In addition, patients who were initially treated by breast conservation and on histological examination were shown to have a tumour that went to the margin of excision were subsequently treated by mastectomy. Thus, breast-conserving surgery is appropriate for single tumours that are small enough in relation to the size of the breast so as to enable removal with an adequate margin and without causing marked distortion. Confirmation that the margins of excision are clear of tumour is important. However, patients with larger tumours, multifocal tumours or a single invasive tumour with extensive ductal carcinoma in situ are still best treated by a mastectomy.

Key Points

 
• Radical mastectomy, previously the standard treatment for breast cancer, involves removal of the whole breast, the underlying chest muscles and the contents of the axilla.
 
• Recent long-term trials have shown that less extensive ‘breast conserving’ surgery gives eqiuvalent survival in selected patients.
 
• Breast-conserving surgery is now appropriate for patients with breast cancers small enough to allow removal with an adequate margin of disease-free tissue.
 
• Mastectomy still required for larger and multifocal tumours.
 
• The best treatment for the contents of the axilla remains to be determined, but recent studies indicate this could be managed by selective rather than radical surgery.

The management of the axilla remains controversial. In both of the studies published recently in the NEJM the axilla was treated by a radical surgical approach in which the axilla was cleared of its contents up to at least the medial border of pectoralis minor (level II clearance). A more selective approach to the axilla would be logical. Two randomised studies comparing a four node axillary sampling procedure (with radiotherapy to the axilla only if the nodes are positive) to a surgical clearance have shown that this approach is effective and associated with less morbidity. The sentinel node biopsy technique, which identifies the first node that drains the tumour-bearing region of the breast, has been shown to be over 90% accurate in determining node status of the axilla, and should allow a selective approach.

Thus, using procedures based on present evidence, many patients with breast cancer need not lose their breast or suffer the consequences of radical axillary dissection if correctly selected for less mutilating procedures.

References

 
1. Hamilton T, Langlands AW, Prescott RJ. The treatment of operable cancer of the breast: a clinical trial in the South-East Region of Scotland. Br J Surg 1974; 61:758-61.
 
2. Veronesi U, Cascinelli N, Mariani L et al. Twenty year follow-up of a randomised study comparing breast-conserving surgery with radical mastectomy for early breast cancer. New Eng J Med 2002; 347:1227-32.
 
3. Fisher B, Anderson S, Bryant J et al. Twenty year follow-up of a randomised trial comparing total mastectomy, lumpectomy, and lumpectomy plus irradiation for the treatment of invasive breast cancer. N Eng J Med 2002; 347:1233-41.
 
4. Chetty U, Jack W, Prescott RJ et al. on behalf of the Edinburgh Breast Unit. Management of the axilla in operable breast cancer treated by breast conservation: a randomised clinical trial. Br J Surg 2000; 87:163-9.
 
5. Forrest AP, Everington D, Steele RJ et al. The Edinburgh randomised trial of axillary sampling, or clearing, after mastectomy. Br J Surg 1995; 82:1504-08.

Mr U Chetty, Consultant Surgeon, Edinburgh Breast Unit, Western General Hospital, Edinburgh, Scotland